4.3.1 Men

1. Adrian MJ, Singh M & Karpovich PV (1966): Energy cost of leg kick, arm stroke, and whole crawl stroke. .J.Appl.Physiol 21,1763-1766.

The net energy costs of the leg kick, arm stroke and whole stroke of the crawl were determined and formulas for the calculation of oxygen requirement derived. Results showed that for a given speed the energy cost of the leg kick was two to four times greater than that of the arm stroke and whole stroke. The energy cost of the arm stroke was less than that of the whole stroke up to a velocity of 3.35 ft/sec. The formulas for oxygen consumed per minute derived from test on the best swimmer are: 02 for the legs = 1.32 V^2,05; 02 for the arms = V^3,95/20.42; and 02 for the whole stroke = V^2,70/4,38 (V= velocity, ft/sec). The energy cost given here pertains to actual swimming and not to conventional swimming, which consists not only of swimming but of a dive and push-offs which inflate the so-called average velocity. The efficiency of the leg kick ranged from 0.05-1.23%, whereas the arm stroke ranged from 56-6.92%. The efficiency of the whole stroke was slightly higher than that reported in other studies and ranged from 1.71-3.99%. Results obtained substantiate opinions of swimming coaches that in long-distance crawl the leg action should be reduced to a minimum.

2. Boyle PM, Mahoney CA & Wallace WF (1994): The competitive demands of elite male field hockey. J.Sports Med.Phys.Fitness. 34, 235-241.

Physical and Health Education Unit, Queen's University of Belfast, Northern Ireland. To establish the energy cost of competitive field hockey, nine international hockey players wore a modified Sport Tester PE3000 telemetric heart rate monitor during matchplay and also completed a laboratory based incremental treadmill test to establish maximal oxygen uptake VO2max The heart rate data from competition were compared with heart rate and oxygen uptake data measured in the laboratory. Individual regression equations were established from these data to estimate the energy expenditure during competitive match-play. The mean heart rate during competition was 159 +/- 8 beats/min (mean +/- SD). The mean estimated oxygen uptake during competition was 48.2 +/- 5.2 ml/kg/min which is commensurate with 78% of the group's mean maximal oxygen uptake of 61.8 +/- 1.8 ml/kg/mint The mean estimated energy expenditure throughout an entire match was 5.19 MJ and rates of energy expenditure ranged from 83 kJ/min for the centre midfield position to 61.1 kJ/min for the left corner forward position. This study has shown the feasibility of heart rate monitoring as a means of estimating energy expenditure in elite hockey. Competitive matches place a heavy demand on the aerobic system and require players to expend energy at relatively high levels.

3. Brueckner JC, Atchou G. Capelli C, Duvallet A, Barrault D, Jousselin E, Rieu M & di Prampero PE (1991): The energy cost of running increases with the distance covered. Eur.J.Appl.Physiol 62, 385-389.

Department of Physiology, CMU, Geneva, Switzerland. The net energy cost of running per unit of body mass and distance (Cr. ml O2.kg-1.km-1) was determined on ten amateur runners before and immediately after running 15, 32 or 42 km on an indoor track at a constant speed. The Cr was determined on a treadmill at the same speed and each run was performed twice. The average value of Cr. as determined before the runs, amounted to 174.9 ml O2.kg-1.km-1, SD 13.7. After 15 km, Cr was not significantly different, whereas it had increased significantly after 32 or 42 km, the increase ranging from 0.20 to 0.31 ml O2.kg-1.km-1 per km of distance (D). However, Cr before the runs decreased, albeit at a progressively smaller rate, with the number of trials (N), indicating an habituation effect (H) to treadmill running. The effects of D alone were determined assuming that Cr increased linearly with D, whereas H decreased exponentially with increasing N. i.e. Cr = Cr0 + a D + He-bN. The Cr0, the "true" energy cost of running in nonfatigued subjects accustomed to treadmill running, was assumed to be equal to the average value of Cr before the run for N equal to or greater than 7 (171.1 ml O2.kg-1.km-1, SD 12.7; n=30). A multiple regression of Cr on N and D in the form of the above equation showed first, that Cr increased with the D covered by 0.123%.km-1, SEM 0.006 (ie about 0.22 ml 02.kg-1 per km, P<0.001); second, that in terms of energy consumption (obtained from oxygen consumption and the respiratory quotient), the increase of Cr with D was smaller, amounting on average to 0.08%.km (0.0029 J.kg-1.m-1, P<0.001); and third that the effects of H amounted to about 16% of CrO for the first trial and became negligible after three to four trials.

4. Capelli C, Rosa G. Butti F. Ferretti G. Veicsteinas A & di Prampero PE (1993): Energy cost and efficiency of riding aerodynamic bicycles. Eur.J.Appl.Physiol 67, 144-149.

Dipartimento di Scienze e Tecnologie Biomediche, Sezione di Fisiologia, Udine, Italy. Traction resistance (Rt) was determined by towing two cyclists in fully dropped posture on bicycles with an aerodynamic frame with lenticular wheels (AL), an aerodynamic frame with traditional wheels (AT), or a traditional frame with lenticular wheels (TL) in calm air on a flat wooden track at constant speed (8.6-14.6 m.s-1). Under all experimental conditions, Rt increased linearly with the square of air velocity (v2a); r2 equal to greater than 0.89. The constant k = delta Rt/delta v2a was about 15% lower for AL and AT (0.157 and 0.155 N.s2 x m-2) than for TL bicycles (0.184 N.s2 x m-2). These data show firstly, that in terms of mechanical energy savings, the role of lenticular wheels is negligible and, secondly, that for TL bicycles, the value of k was essentially equal to that found by others for bicycles with a traditional frame and traditional wheels (TT). The energy cost of cycling per unit distance (Cc, J.m-1) was also measured for AT and TT bicycles from the ratio of the 02 consumption above resting to speed, in the speed range from 4.7 to 11.1 m.s-1. The Cc also increased linearly with v2a, as described by: Cc = 30.8 + 0.558 v2a and Cc = 29.6 + 0.606 v2a for AT and TT bicycles. Thus from this study it would seem that AT bicycles are only about 5% more economical than TT at 12.5 m.s-1 the economy tending to increase slightly with the speed. Assuming a rolling coefficient equal to that observed by others in similar conditions, the mechanical efficiency was about 10% lower for aerodynamic than for conventional bicycles, amounting to about 22% and 25% at a speed fo 12.5 m.s-1. From these data it was possible to calculate that the performance improvement when riding aerodynamic bicycles, all other things being equal, ought to be about 3%. This compares favourably with the increase of about 4% observed in world record speeds (over distances from 1 to 20 km) after the adoption of new bicycles.

5. Chatard JC, Lavoie JM & Lacour JR (1990): Analysis of determinants of swimming economy in front crawl. Eur.J.Appl.Physiol 61, 88-92.

Laboratoire de Physiologie, GIP Exercice, Faculte de Medecine, Saint-Etienne, France. The purpose of this study was to investigate the relationship between swimming economy, energy cost to move the body per unit distance (CS) at a given velocity (v) and the potential determinants, i.e. performance level, body size, swimming technique and v. A total of 101 males were studied. Three performance levels (A, B. C) were determined, ranging from the slower (A) to the faster times (B. C). At level C and at 1.1 m.s- 1, CS 1.1, was reduced by 55% and 25% when compared with levels A and B and when calculated per unit of surface area (SA) and unit of hydrostatic lift (HL). For the whole group of swimmers, CS 1.1 = 21.88 SA-2.15 HL + 5.9 (r = 0.56, P less than 0.01). Among the 101 swimmers, three other groups were selected to evaluate specifically the influence of arm length and swimming technique on CS, i.e. arm or leg swimmers and sprinters versus long-distance swimmers. CS was significantly (P less than 0.05) lower for long-arm swimmers, arm and long-distance swimmers than for short-arm, leg and sprint swimmers by 12%, SD 3.3%, 15%, SD 3.8% and 16.5%, SD 3%, respectively. For all groups, CS increased with v on average by 10% every 0.1 m.s-1. It is concluded that technical ability cannot be interpreted directly from CS. Performance levels, body size, swimming technique and v at which the measurements are obtained must be also taken into account.

6. di Prampero PE, Cortili G. Celentano F & Cerretelli P (1971): Physiological aspects of rowing. .J.Appl.Physiol 31, 853-857.

Heart rate, O2 uptake and lactic acid production together with the mechanical work performed have been investigated in man a) during simulated rowing in a basin and b) during actual rowing on a racing shell. Heart rate and 02 uptake are linearly correlated, the relationship being substantially the same for both simulated and actual rowing as for other forms of exercise. Pulmonary ventilation determined in simulated rowing is a linear function of VO2, the energy taken up by the muscles per liter of expired air being 0.26 ± 0.027 kcal. The mechanical efficiency is lower in simulated (0.1) than in actual (0.18) rowing at low stroke frequencies (<25).

It approaches in both cases a maximal level of 0.2-0.23 at high frequencies (35/min). During actual rowing the mechanical power output necessary to maintain the boat progression as well as the energy expenditure appear to increase as the 3.2 power function of the average speed.

7. di Prampero PE, Cortili G. Mognoni P & Saibene F (1976): Energy cost of speed skating and efficiency of work against air resistance. .J.Appl.Physiol 40, 584-591.

The energy expenditure during speed ice skating (P_B=650 mmHg; T=-5 degrees C) was measured on 13 athletes (speed range: 4-12 m/s) from VO₂ and (for speeds greater than 10 m/s) from blood lactic acid concentration. The energy spent (O₂ equivalents) per unit body wt and unit distance (E_tot/V, ml/kg.min) increases with the speed (v, m/s): E_tot/v=0.049 + 0.44 X 10 _-3 V₂. At 10 m/s, V_tot/V amounts then to 0.093 ml/kg-m: about half the value of running. The constant 0.049 ml/kg-m is interpreted as the energy spent against gravitational and inertial forces. The term 0.44 X 10 _-3 V₂ indicates the energy spent against the wind, the constant 0.44 X 10 _-3 ml.s₂.kg_-1m_-3 being a measure of k/e, where k is the coefficient relating drag to v2, and e the efficiency of work against the wind. From a direct estimate of k in a wind tunnel, e was calculated as 0.11. In running, skating, and cycling k/e is similar (approximately 0.020 ml.s₂.m_-3 per m2 body area), hence at a given speed the energy spent against the wind is equal. On the contrary, the energy spent against other forces decreases in the above order: 0.19, 0.05, 0.018 ml.m_-1, per kg body wt. This explains the different speeds attained in these exercises with the same power output.

8. di Prampero PE, Pendergast CR, Wilson DW & Rennie DW (1974): Energetics of swimming in man. .J.Appl.Physiol 37,1-5.

Body drag, Db, and mechanical efficiency, e, during actual swimming were measured by a new method on 10 men swimming the overarm crawl at velocities, v, of 0.55 and 0.9 m.s^-1 in a 60 -m-circumference annular pool. Db measured during swimming was double that for passive towing, as was e. The ratio, e/Db, was observed to be the same for a given individual at the two velocities, averaging 0.8 kg^-1 X 10^-2, but varied from 0.42 to 1.05 kg^-1 X 10^-2 among individuals. It can be shown theoretically that v = VO2net X (e/Db) for aerobic swimming; hence the ratio e/Db establishes the velocity a person can achieve for a given VO2net and is an index of individual proficiency in swimming. The reciprocal of e/Db is equivalent to VO2/v, e.g., the energy cost of swimming 1 m. This proved to be independent of the two velocities studied and averaged 58.5 ml O2.m^-1, about four times the cost of running for men of this size. The basic approach and the quantitative analysis of swimming proficiency in terms of the ratio e/Db have promise for the study of many forms of locomotion on or under the water surface.

9. Getchell LH (1968): Energy cost of playing golf. Arch.Phys.Med.Rehabil. 49, 31-35.

Indirect calorimetric procedures using a portable dry gas meter were used to determine the caloric cost of playing golf under foursome conditions. Four middle-aged men were tested in selected golf tasks in conjunction with a time-motion analysis and in the playing of three holes of golf. The rate of 3.7 cal per minute (3.3 cal per kilogram per hour) was determined as the caloric cost of playing golf. The results of this study suggest that the accepted value of 5 cal per minute (4.8 cal per kilogram per hour) for golf is possibly too high for foursome playing conditions.

10. Gray GL, Matheson GO & McKenzie DC (1995): The metabolic cost of two kayaking techniques. Int.J.Sports Med. 16, 250-254.

Allan McGavin Sports Medicine Centre, University of British Columbia, Vancouver, Canada. A common technique employed in flatwater kayak and canoe races is "wash riding", in which a paddler positions his/her boat on the wake of a leading boat and, at a strategic moment, drops off the wake to sprint ahead. It was hypothesized that this manoeuver was energy efficient, analogous to drafting in cycling. To study this hypothesis, minute ventilation (VE), heart rate (HR) and oxygen consumption (VO2) were measured in 10 elite male kayak paddlers (age = 25 +/- 6.5 yrs, height = 183.6 +/- 4.4 cm, mass = 83.9 +/- 6.1 kg) during steady-state exercise at a standardized velocity in conditions of "wash riding" (WR) and "non-wash riding" (NWR). The data were collected in field conditions using a portable telemetric metabolic system (Cosmed K2). Statistical analysis of the mean values for VE, VO2 and HR was performed using the Hotelling's T2 statistic and revealed significant (p < 0.05) differences between the WR and NWR trials for all three dependent variables. Mean values for VE (I/min) were WR = 113 +/- 16.5, NWR = 126.3 +/-15.7; for VO2 (I/min) were WR = 3.22 +/- 0.32, NWR = 3.63 +/- 0.3; and for HR (bpm) were WR = 167 +/- 9.9, NWR = 174 +/- 8.0. It was concluded that wash riding during kayak paddling confers substantial metabolic savings at the speeds tested. This has implications for the design of training programs and competitive strategies for flatwater distance kayak racing.

11. Hoffman MD & Clifford PS (1990): Physiological responses to different cross country skiing techniques on level terrain. Med.Sci.Sport Exerc. 22, 841-848.

Department of Physical Medicine, Medical College of Wisconsin, Milwaukee. This study compared the physiological responses and ratings of perceived exertion elicited by several of the most common currently used cross country skiing techniques. The comparison included two classical techniques (kick double pole and diagonal stride), two ski skating techniques (V1 skate and marathon skate), and the double pole technique on both classical and skating skis. Eight male cross country ski racers skied each technique for three laps around a 420 m flat, professionally groomed and tracked oval surface at a mean (+/- SD) velocity of 14.2 +/- 0.6 km.h-1. Heart rate was recorded by telemetry and expired gases were collected for determination of minute ventilation and oxygen consumption during the final minute of each bout. Rating of perceived exertion was requested immediately after each bout. It was found that the diagonal stride technique required the highest oxygen consumption, with the V1 skate, marathon skate, and kick double pole techniques inducing a 16% lower (P less than 0.01) oxygen cost, and the double pole technique inducing a 26% lower (P less than 0.01) oxygen cost. Heart rate was also highest (P less than 0.01) with the diagonal stride technique and lowest with the double pole technique. The rating of perceived exertion was greatest (P less than 0.05) for the diagonal stride technique and lowest (P less than 0.05) for the V1 skate technique. These results indicate that the double pole technique has the greatest economy, the diagonal stride technique elicits the greatest physiological demands and has the highest perceived effort, and the V1 skate technique is associated with the lowest perceived effort under the conditions of this study.

12. Hoffman MD, Clifford PS, Foley PJ & Brice AG (1990): Physiological responses to different roller skiing techniques. Med.Sci.Sport Exerc. 22, 391-396.

Department of Physical Medicine, Medical College of Wisconsin, Milwaukee. This study compared the physiological responses during roller skiing with the V1 skate, kick double pole, and double pole techniques. Eight male nordic ski racers roller skied over a flat one-mile track at 14 and 18 km.h-1 using each of the three techniques under study. Heart rates and oxygen uptakes were measured during the last minute of each bout, ratings of perceived exertion were requested immediately after each bout, and capillary blood lactate concentrations were determined 3 min after each bout. The double pole technique was found to be significantly more economical (P less than 0.05) than the other techniques, as demonstrated by a 12% lower oxygen consumption. No differences were found between the V1 skate and the kick double pole techniques for any of the variables studied. The findings of similar physiological responses with the V1 skate and kick double pole techniques suggest that these techniques should induce similar cardiovascular adaptations when roller skiing at the same speed on flat terrain.

13. Holmer I (1974): Energy cost of arm stroke, leg kick, and the whole stroke in competitive swimming styles. Eur.J.Appl.Physiol 33,105-118.

In male elite swimmers V_O2 at a given velocity in freestyle and back-stroke was on average 1 to 21 x min-1 lower as compared with breaststroke and butterfly. Except for breaststroke, swimming with arm strokes only demanded a lower VO2 at a given submaximal velocity than the whole stroke. In freestyle and backstroke the submaximal V^O2 of leg kick at a given velocity was clearly higher than the whole stroke. The highest velocity during maximal swimming was always attained with the whole stroke, and the lowest with the leg kick, except for breast stroke, where the leg kick was most powerful. At a given submaximal V_O2, heart rate and V_E V_O2 tended to be higher during swimming with arm strokes only as compared with the whole stroke. Highest values for V_O2, heart rate and blood lactate during maximal exercise were almost always attained when swimming the whole stroke, and lowest when swimming with arm strokes only. At higher velocities body drag was 0.5 to 0.9 kp lower when arms or legs were supported by a cork as compared with body drag without support.

14. Hunter GR, Montoye HJ, Webster JG, Demment R. Ji LL & Ng A (1989): The validity of a portable accelerometer for estimating energy expenditure in bicycle riding. J.Sports Med.Phys.Fitness, 29, 218-222.

The purpose of the investigation was to determine the validity of a portable vertical accelerometer and a Large-Scale Integrated Motor Activity Monitor (LSI) for estimating energy expenditure in riding a bicycle at various velocities. Instrument placement was either at the knee or ankle. Energy consumption, i.e. oxygen consumption VO2 was determined during bicycle rides after steady state metabolism was reached. Standard errors of estimate were used to express the accuracy of estimating VO2 from accelerometer or LSI recordings. The reliability of the vertical accelerometer was found to be satisfactory. The vertical accelerometer was also effective for estimating VO2 in bicycling (standard errors of estimate = 3.3 to 4.4 ml.kg-1.min-1). The accuracy of the LSI was not as good; the standard errors of estimate being = 5.9 to 8.5 ml.kg1.min-1.

15. Jette M, Mongeon J & Routhier R (1979): The energy cost of rope skipping. J.Sports Med.Phys.Fitness, 19, 33-37.

This study was designed to measure the energy cost of different intensities of rope skipping for the purpose of exercise prescription. Five male subjects between the ages of 22 to 39 participated in the study. Expired air for gas analysis was collected during simulated intervals of rope skipping periods. The net energy cost in kcal/hr per kg were as follows: level A (66 tpm (turns per minute), one foot skip, plain bounce): 10.61; level B (66 tpm, one foot skip, rhythm bounce): 9.89; level C (66 tpm, two-feet skip, plain bounce): 10.27; level D (66 tpm, two-feet skip, rhythm bounce): 9.05; level E (84 tpm, two-feet skip, plain bounce): 11.02; level F (102 tpm, two-feet skip, plain bounce): 12.58; level G (120 tpm, two-feet skip, plain bounce): 11.91; level H (132 tpm, two-feet skip, plain bounce): 11.55. ANOVA and the SCHEFFE test revealed a significant statistical difference only between levels D and F (.05 level). Mean terminal heart rates ranged from 146 b/min for level D to 176 b/min for level F. Lactate response reached mean values of 51 mg% for level D and 110 mg% for level F. The results indicate that rope skipping can be classified as heavy to exhausting work.

16. Jette M, Thoden JS & Spence J (1976): The energy expenditure of a 5 km cross-country ski run. J.Sports Med.Phys.Fitness, 16, 134-137.

This study was designed to directly determine the net energy cost of skiing a typical 5 km run at competitive speed. Three members of the Canadian National Cross-Country Ski Team were employed as subjects. Pulmonary ventilations were collected with a KM respirometer and expired air was analyzed in situ. EKG recordings were monitored throughout the run. The net mean energy expenditure for the run was established at 20.9 cal/min or 0.296 Cal/kg/min. This would represent a caloric expenditure of 483 Cal for a 70 kg male completing the course in 23 min. 33 sec. In terms of VO2 per kg body weight it was determined that the skiers performed at a mean VO2 of 59.8 ml/kg/min or 90% of their treadmill induced max VO2 measured under laboratory conditions. The practical applications of this study are discussed.

17. Klissouras V (1968): Energy metabolism in swimming the dolphin stroke. Int.Z.angew. Physiol.einschl.Arbeitsphysiol. 25, 142-150.

The energy metabolism of subjects while they swam using the dolphin-butterfly stroke was analyzed. It was found that: 1. The oxygen consumption while swimming with the whole stroke, the arm-stroke or leg-kick, increased exponentially with an arithmetical increase in swimming velocity. 2. At competitive speeds swimming with only the leg-kick requires more energy than swimming at the same velocity with either the arm-stroke or the whole stroke. 3. A parabolic pattern is shown for the mechanical efficiency while swimming by use of each of the three methods. The mechanical efficiency increases as the velocity of swimming increases from 0 to an optimum velocity and then decreases as the velocity exceeds this value. 4. At competitive speeds swimming with only the leg-kick is less efficient than swimming with either the arm-stroke or the whole stroke. 5. At maximum speeds swimming with the whole stroke is slightly more efficient than swimming with the arm-stroke. The shortcomings of the "oxygen-dept" method for the measurement of oxygen consumption during submaximal exercise are discussed.

18. Knowlton RG, Ackerman KA & Kaminsky LA (1988): Physiological and performance comparisons of running flat and hill routes as applied to orienteering navigation. J.Sports Med.Phys.Fitness, 28, 189-193.

Twenty-six men ran under simulated orienteering conditions to determine performance and energy expenditure characteristics required of a flat route (FR) and two hill routes; one a gradual incline (GI) and one an abrupt incline (Al). The actual speed was greater on FR but slower when computed by the straight line distance as is done by orienteering convention. The energy requirement for FR was the higher, 23.8 kcal, and the least for Al, 17.5 kcal. Although the two hill courses were identical in length, there was a significant difference in energy expenditure between Gl, 18.9 kcal, and Al, 17.5 kcal. It was speculated that contrasts in the duration of positive and negative work accounted for the differences in energy expenditure between the two hill routes. The perception of exertion, RPE was nearly identical (10.6) for the three routes. Although the energy demands were similar, it was concluded that speed calculated by orienteering convention was the most reasonable criterion for route selection. This was supported by the examination of forty-seven experienced orienteers of maps representing the test routes of this study. Although Al proved the preferable choice, it is proposed that 1.8 units of flat distance to each unit of gradual climb is a reasonable criterion for route selection, at least for a 10 m hill. This refutes the 10:1 ratio suggested in the early orienteering literature.

19. Marion GA & Leger LA (1988): Energetics of indoor track cycling in trained competitors. Int.J.Sports Med. 9, 234-239.

Departement d'Education physique, Université de Montreal, Quebec, Canada. Steady-state track VO2 was estimated by means of the retroextrapolation method in seventeen competitive male cyclists at speeds ranging from 28 to 43 km.h-1. Peak VO2 was also determined using an ergocycle multistage test (80 rev.min-1). Results showed large VO2 variations at similar speeds on the track (SEE greater than 10% Y; n = 17). Third degree regressions were the most accurate to describe the evolution of VO2 with speed, while the units ml.kg-0.667.min-1 showed better correlations and lower dispersions than 1.min-1, ml.kg-1.min-1, and 1.min-1.m-2. When categorized according to the Quebec Cycling Federation ranking, (elites: n = 6; nonelites: n = 11), the elites tended to demonstrate to a lower mean VO2 for the range of velocities studied. The difference was, however, not statistically significant (P greater than 0.05). Interindividual variations were reduced by expressing VO2 and speed as relative percentages of maximal values in ten subjects: % MAP = 6.475 e exp [0.0274% MAS] where % MAP = track V02/laboratory peak VO2, and % MAS = speed/speed associated with peak VO2 on the track. No significant difference was observed between track and ergocycle peak VO2 (P greater than 0.05), indicating the validity of the 80 rev.min-1 protocol for laboratory evaluation of racing cyclists. The concept of cycling economy as a contributing factor to performance and applications of the % MAP-% MAS relationship are discussed.

20. McArdle WD, Glaser RM & Magel JR (1971): Metabolic and cardiorespiratory response during free swimming and treadmill walking. .J.Appl.Physiol 30, 733-738.

The VO2 and telemetered HR and ventilatory response during free swimming and walking were studied in five male trained college swimmers. The swimming and walking tests were of the discontinuous type in which the subject exercised for 4-min at increasing work levels up to maximum. During walking, work was regulated by increasing the elevation of the treadmill. In the swimming test, work was altered by increasing the stroke frequency by means of an electronic pacing device. VO2 was essentially linearly related to work intensity in the swimming and walking tests. However, the slope of the HR-V02 line was shifted to the right during free swimming. For any level of VO2 within the range measured, the HR during swimming averaged 9-13 beats/min lower than the HR walking. Maximum HR averaged 22 beats/min lower in the swimming test (P<0.01). At VO2 above 2.0 L/min breathing frequency was approximately the same in both forms of exercise with a tendency for it to be slightly higher during swimming. At submaximal work levels VE was quite similar in both forms of work. However, the maximum VE and breathing rate were significantly higher in walking than in swimming. During submaximal work oxygen extraction was generally higher in swimming throughout the entire range of work. The energy cost of swimming at various speeds is presented in relation to previously reported data.

21. McCole SD, Claney K, Conte J. Anderson R & Hagberg JM (1990): Energy expenditure during bicycling. .J.Appl.Physiol 68, 748-753.

Department of Exercise and Sport Science, College of Health and Human Performance, University of Florida, Gainesville 32611. This study was designed to measure the 02 uptake VO2 of cyclists while they rode outdoors at speeds from 32 to 40 km/in. Regression analyses of data from 92 trials using the same wheels, tires, and tire pressure with the cyclists riding in their preferred gear and in an aerodynamic position indicated the best equation (r = 0.84) to estimate VO2 in liters per minute VO2 = - 4.50 + 0.17 rider speed + 0.052 wind speed + 0.022 rider weight where rider and wind speed are expressed in kilometers per hour and rider weight in kilograms. Following another rider closely, i.e., drafting, at 32 km/in reduced VO2 by 18 +/11 %; the benefit of drafting a single rider at 37 and 40 km/in was greater (27 +/- 8%) than that at 32 km/in. Drafting one, two, or four riders in a line at 40 km/in resulted in the same reduction in VO2 (27 +/- 7%). Riding at 40 km/in at the back of a group of eight riders reduced VO2 by significantly more (39 +/- 6%) than drafting one, two, or four riders in a line; drafting a vehicle at 40 km/in resulted in the greatest decrease in VO2 (62 +/- 6%). VO2 was also 7 +/- 4% lower when the cyclists were riding an aerodynamic bicycle. An aerodynamic set of wheels with a reduced number of spokes and one set of disk wheels were the only wheels to reduce VO2 significantly while the cyclists were riding a conventional racing bicycle at 40 km/in. Thus drafting and using aerodynamically designed equipment can alter the energy expenditure of cyclists at speeds similar to those encountered at competitive events (32-40 km/h).

22. Myles WS (1979): The energy cost of an 80 km run. Br.J.Sports Med. 13, 12-14.

Data was collected from two men who attempted an 80 km run. Measurements of aerobic power VO2 max) and determinations of heart rate (HR) and submaximal oxygen consumption VO2 during treadmill running were carried out one week before the run. Throughout the 80 km run, HR was recorded by telemetry and used together with the laboratory data to estimate VO2 as a percentage of VO2 max. One subject completed the 80 km distance at 58% of VO2 max. the other subject, operating at 74% of VO2 max. was obliged to retired after 55 km. The data in this and other studies indicate that the high energy costs reported for the marathon (70-85% of VO2 max) cannot be sustained over the 80 km distance but that about 60% of VO2 max can be continued for seven hours and longer.

23. Nadel ER, Holmer I, Bergh U, Astrand PO & Stolwijk JA (1974): Energy exchanges of swimming man. .J.Appl.Physiol 36, 465-471.

Three male swimmers underwent 10-min resting and 20-min swimming (breaststroke) exposures in a swimming flume. Water temperatures in separate exposures were 18, 26 and 33 °C. At each water temperature the subjects rested and swam at water velocities of 0.50, 0.75 and 0.95 m.s^-1, which were designed to produce around 40, 70 and 100% of maximal aerobic power. Measurements were made of esophageal temperature (T_es), four skin temperatures, water temperature, heat flow from five local skin surfaces (Hatfield-Turner discs), and oxygen uptake (VO2). Calculations were made of mean area-weighted skin temperature (Ts) and heat flow, metabolic rate and heat storage. Internal body temperature changes after 20 min of swimming were related to water temperature, swimming intensity and body composition. VO2 was proportional to swimming speed during submaximal efforts in any swimming speed and became greater as the swimmer approached his maximal effort. VO2 was also greater in 18 °C than in 26 °C water at any submaximal swimming speed and likewise greater in 26°C than in 33°C water. Increased cost of swimming in cold water was largely attributed to shivering. The convective heat transfer coefficient was calculated from heat flow and skin and water temperature data and was found to be 230 W.m^-2.°C^-1 at rest in still water, 460 W.m^-2.°C^-1 at rest in moving water, and 580 W.m^-2.°C:⁰¹ while swimming, regardless of swimming speed. Core-to-skin conductances were primarily related to internal temperature, although there appeared to be a minor effect of T_s modifying this relation.

24. Niinimaa V, Dyon M & Shephard RJ (1978): Performance and efficiency of intercollegiate cross-country skiers. Med.Sci.Sport Exerc. 10, 91-93.

Ten male intercollegiate cross-country skiers were studied to identify factors influencing competitive performance and to estimate the efficiency of energy expenditure in skiing. The variables examined were maximum oxygen intake, as determined by both uphill treadmill running and by maximal level skiing, physical characteristics, strength and experience in cross-country skiing and racing. Multiple regression analysis showed that racing experience, cardiorespiratory fitness, and body fat percentage were significant factors in racing success. The net mechanical efficiency at this level of competition was estimated at 21.3%.

25. Reilly T & Thomas V (1979): Estimated daily energy expenditures of professional association footballers. Ergonomics, 22, 541-548.

The daily energy demands of 23 professional English League footballers were estimated. Indirect measurement was made of energy expended in training, match-play and non-occupational activity. Mean duration of training was 75 min day^-1, mean heart rate 132 beats min^-1. Match-play constituted the dominant source of occupational strain, mean heart rate being 157 beats min ^-1 in outfielders. Temporal commitment to work was 18.5 h week ^-1 during which mean work intensity could be described as moderate. Time spent inactive was 19.5 h day-1 and daily energy expenditure was estimated to be 14.442 MJ. It was concluded that physiological strain in this occupation was not excessive and no peculiar dietary requirements obtained.

26. Saibene F. Cortili G. Gavazzi P & Magistri P (1985): Energy sources in alpine skiing (giant slalom). Eur.J.Appl.Physiol 53, 312-316.

The energy cost of a giant slalom event was measured in eight skiers of national level. The lap lasted on average 82 s. VO2 was measured during the first, the second and the last third of the lap in different trials and also during recovery from a complete lap. Blood lactate was measured at the end of a lap. From the data obtained it was possible to calculate that: a) VO2 as measured during the lap, would correspond at steady state to 80% of the VO2max of the subjects; b) the total metabolic power delivered during the lap should be equal to about 72 ml 02.kg-1.min-1, corresponding to 120% of VO2max of the subjects. Considering the short duration of the trial and the power output delivered during maximal efforts on a bicycle ergometer, it appears that the giant slalom is not a very high energy demanding event.

27. Saibene F. Cortili G. Roi G & Colombini A (1989): The energy cost of level cross-country skiing and the effect of the friction of the ski. Eur. J.Appl.Physiol 58, 791-795.

Istituto Tecnologie Biomediche Avanzate, C.N.R., Milano, Italy. Oxygen consumption VO2 in ml.kg-1.min-1], blood lactate concentration ([La] in mM) and dynamic friction of the skis on snow [(F) in N] were measured in six athletes skiing on a level track at different speeds [(v) in m.min-1] and using different methods of propulsion. The VO2 increased with v and F. the latter depending mostly on snow temperature, as did [La]. The VO2 was very much affected by the skiing technique. Multiple regression equations gave the following results: with diagonal stride (DS), VO2 = -23.09 + 0.189 v + 0.62 N; with double pole (DP), VO2 = -30.95 + 0.192 v + 0.51 N; and with the new skating technique (S), VO2 = -32.63 + 0.171 + 0.68 N. In terms of VO2 DS is the most expensive technique, while S is the least expensive; however, as F increases, S. at the highest speed, tends to cost as much as DP. At speeds from 18 to 22 km.h-1, the speeds measured in the competitions, the F for DS and DP can represent from 10% to 50% of the energy expenditure, with F ranging from 10 to 60 N; with S this range increases to 20%-70%. This seems to depend on the interface between the skis and the snow and on the different ways the poles are used.

28. Schmidt RJ, Housh TJ & Hughes RA (1985): Metabolic response to kendo. J.Sports Med. Phys. Fitness, 25, 202-206.

To determine the physiological intensity and aerobic cost of playing kendo, the heart rate responses of eight subjects (mean age 28 +- 4.8 years) were monitored continuously via radiotelemetry during a 5-minute kendo bout (jigeiko). In addition, aerobic capacity (VO2max) and heart rate values were determined during a treadmill test employing continuous incremental protocol and compared to values obtained during kendo jigeiko. The mean playing VO2 was 45 +7.6 ml/kg.min-1 representing 89% of VO2max and 111% of anaerobic threshold (AT). The mean metabolic intensity was 14.6 +- 0.7 METS. The caloric equivalent for the mean playing R value (0.99 +- 0.09) was 5.04 kcal/liter 02. The mean caloric expenditure during competition was 15.64 +- 3.06 kcal/min. Spearman Rank Order correlations revealed that of the physiological variables measured, only VO2max was significantly (p<0.05, r₃=-0.79) associated with kendo playing ability. These findings indicate that kendo jigeiko of 5 minuses' duration is of sufficient intensity and duration to stimulate cardiorespiratory fitness. The use of the arms, grip on the shinai, and the explosive nature of the techniques may serve as mechanisms for the elevation of the heartrate. Furthermore, oxidative metabolic factors (particularly VO2max contribute substantially in ability between competitors.

29. Seliger V (1968): Energy metabolism in selected physical exercises. Int.Z.angew.Physiol. einschl.Arbeitsphysiol. 25, 104-120.

The energy costs of 15 physical activities were examined in 275 subjects under training conditions of the particular activity. The sample contains usually 15 medium athletically developed persons at minimum. The energy metabolism was followed by indirect calorimetrical method, the heart rate was registered throughout the experimental telemetrically. The activities were divided into three groups, according to the time of duration. The results showed that the energy expenditure ranges were in A-group (duration 5 min and more) 0.08-0.26 kcal/min/kg, in B-group (1-3 min) Q.11-0.45 kcal/min/kg, and in C-group (1-30 see) 0.68-1.75 kcal per min/kg. The observed values of heart rate, pulmonary ventilation, and oxygen uptake are discussed. No correlation between the energy expenditure and the intensity of the motional activity, according to pedagogues' observation was found. The relationship to physiological function was with respect to motional activity on 1-5% significance level, especially in sports from groups A and B. A graph was constructed of the relationship of the intensity of metabolism, against duration of the activity. Three fields limited by parallel lines enables the judgement of the real metabolic rate during the sports' activity of examined persons to functional development of his organismus.

30. Seliger V, Ejem M, Pauer M & Safarik V (1973): Energy metabolism in tennis. Int.Z.angew.Physiol. einschl.Arbeitsphysiol. 31, 333-340.

Physiological responses of a group of 16 tennis players have been investigated under the almost natural conditions of a 10 min long training match. Collecting the expired air into Douglas bags, transmitting heart rate all the time of experiment wirelessly and analysing every player's activity, yielded the following main results: The average intensity of metabolism was 919.5% BMR, that is 0.14 kcal per min and kg of body weight. The oxygen uptake have been found 27.3 ml O2/min.kg, while the mean heart rate during the match was counted as 143 beats/mint It was found, too, that players ran totally 240 m, executed in average 62 strokes and used 41.1% of the total time for real play. With regard to our results tennis can be grouped together with bicycleball and American handball, while basketball, European handball, soccer and ice-hockey on one hand, and volleyball with table-tennis on the other hand, differ significantly. There was also found to be significant difference between caloric output in recreational and competitive type of tennis game. This investigation then can support the view that, in the main, tennis means the submaximal load for players.

31. Seliger V, Kostka V, Grusova D, Kovac J. Machovcova J. Pauer M, Pribylova A & Urbankova R (1972): Energy expenditure and physical fitness of ice-hockey players. Int.Z.angew.Physiol. einschl.Arbeitsphysiol. 30, 283-291.

We examined the energy expenditure in ice-hockey players under conditions of a model training match. The results were obtained in a group of 13 players of the national representative team (age 24.4 years), and in 1 goaler. In the players we also followed the physical fitness by means of a loading experiment on bicycle ergometer in the middle of the racing season, and before the opening of the World Championship 1971. The principal results are as follows: the energy expenditure during the play is 0.48 kcal/min.kg (3137%BMR), the oxygen debt 6.3 I. The anaerobic part of the metabolism is approximately two thirds of the total energy expenditure .The average heart rate during the activity on ice was 152 beats per minute, the pulmonary ventilation 92 I, the oxygen uptake 32 ml/min.kg. During one turn (1.17 min) the players covered the distance 285 m. The comparison of maximum values of the indices obtained by ergometrical examination in two examinations did not show any substantial differences. We can assume that the decrease observed in several indices may have been caused by a low motivation at loading up to the maximum (the lactic acid, pulmonary ventilation, oxygen uptake). Other findings (the fat percentage increment) can be explained by less intensive training, unbalance between performance and nutrition. A relative independent index is the W 170 which has shown the unchanged level of cardiorespiratory functions. From the results various conclusions can be drawn for the work of trainers. The ice-hockey proves to be an activity with mostly sub-maximal metabolic rate, where appears a great part of anaerobic metabolism simultaneously with high requirements for the aerobic metabolism. For the training practice the requirements follow to intensify the interval training, to increase the play intensity in the training, to use the necessary number of play exercise requiring the typical anaerobic power, and load the players, in the preparatory period, more often by endurance activities for the aerobic endurance be developed.

32. Smith HK, Montpetit RR & Perrault H (1988): The aerobic demand of backstroke swimming, and its relation to body size, stroke technique, and performance. Eur.J.Appl.Physiol 58, 182188.

Department of Physical Education, McGill University, Montreal, P.Q., Canada. Few studies have examined the aerobic demand of backstroke swimming, and its relation to body morphology, technique, or performance. The aims of this study were thus to: i) describe the aerobic demand of backstroke swimming in proficient swimmers at high velocities; ii) assess the effects of body size and stroke technique on submaximal and maximal 02 costs, and; iii) test for a relationship between submaximal 02 costs and maximal performance. Sixteen male competitive swimmers were tested during backstroke swimming at velocities from 1.0 to 1.4 m.s-1. Results showed that VO2 increased linearly with velocity (m.s-1) following the equation VO2 = 6.28v - 3.81 (r = 0.77, SEE/Y = 14.9%). VO2 was also related to the subjects' body mass, height, and armspan. Longer distances per stroke were associated with lower 02 costs, and better maximal performances. A significant relation was found between VO2 at 1.1 m.s-1, adjusted for body mass, and 400 m performance (r = -0.78). Submaximal VO2 was also related to reported times for 100 m and 200 m races. Multiple correlation analyses indicated that VO2 at 1.1 m.s-1 and VO2max accounted for up to 78% of the variance in maximal performances. These results suggest that the assessment of submaximal and maximal VO2 during backstroke swimming may be of value in the training and testing programs of competitive swimmers.

33. Toussaint HE, Beelen A, Rodenburg A, Sargeant AJ, de Groot G. Hollander AP & van Ingen Schenau GJ (1988): Propelling efficiency of front-crawl swimming. .J.Appl.Physiol 65, 25062512.

Department of Exercise Physiology and Health, Faculty of Human Movement Sciences, Vrije Universiteit, Amsterdam, The Netherlands. In this study the propelling efficiency (ep) of front-crawl swimming, by use of the arms only, was calculated in four subjects. This is the ratio of the power used to overcome drag (Pd) to the total mechanical power (Po) produced including power wasted in changing the kinetic energy of masses of water (Pk). By the use of an extended version of the system to measure active drag (MAD system), Pd was measured directly. Simultaneous measurement of 02 uptake (VO2) enabled the establishment of the relationship between the rate of the energy expenditure (PVO2) and Po (since when swimming on the MAD system Po = Pd). These individual relationships describing the mechanical efficiency (8-12%) were then used to estimate Po in free swimming from measurements of VO2. Because Pd was directly measured at each velocity studied by use of the MAD system, ep could be calculated according to the equation ep = Pd/(Pd + Pk) = Pd/Po. For the four top class swimmers studied, ep was found to range from 46 to 77%. Total efficiency, defined as the product of mechanical and propelling efficiency, ranged from 5 to 8%.

34. van Ingen Schenau GJ, de Groot G & Hollander AP (1983): Some technical, physiological and anthropometrical aspects of speed skating. Eur.J.Appl.Physiol 50, 343-354.

Five elite speed skaters and fourteen well trained skaters of a lower performance level performed three maximal tests: a 3,000 m race from which the skating position and the stroke frequency were derived, an oxygen consumption test both during skating and during a bicycle ergometer test. From all subjects anthropometric measures were taken. The elite group showed a VO2 during cycling of 64.4 +/- 3.5 ml.kg-1.min-1 and 59.4 +/- 3.7 ml.kg-1.min-1 during skating. The elite skaters showed: a shorter upper leg length with respect to total leg length, higher aerobic power during cycling, higher stroke frequency, smaller pre-extension knee angle coupled to higher work per stroke, higher "efficiency" during skating and higher external power during skating and during cycling when compared with the group of lower performance level. It is concluded that an important pre-requisite for speed skating appears to be the possibility to skate at a small pre-extension knee angle without an excessive claim to anaerobic metabolism.

35. Veicsteinas A, Ferretti G. Margonato V, Rosa G & Tagliabue D (1984): Energy cost of and energy sources for alpine skiing in top athletes. .J.Appl.Physiol 56, 1187-1190.

O2 uptake VO2 during exercise and at 2 min of the recovery along with blood lactate concentration 5 min after exercise were measured in an all-out special slalom (SS) and giant slalom (GS) performed by eight top male athletes and five controls in a field study. Heart rate (HR) was continuously monitored before, during, and after each task. On the basis of an energy equivalent of 3.15 ml O2.kg body wt-1 for 1 mmol.1-1 lactate accumulation and the assumption that the amount of 02 consumed in recovery is used to reconstitute approximately phosphates used during the exercise, the total energy cost (delta VO2 tot) could be calculated and subdivided into aerobic, lactic, and alactic fractions. In top athletes, delta VO2 tot was equal during SS and GS [7.28 +/- 1.14 (SD) and 7.47 +/- 0.89 liters for about 55- and 70-s performances, respectively]. When referred to time, the 02 expenditure rate was 2 and 1.6 times VO2max in SS and GS, respectively. In SS and GS, the energy sources were about 40% aerobic, 20% alactic, and 40% lactic metabolism. In control skiers, delta VO2 tot of GS was 6.12 +/- 1.45 liters for 77 s, amounting to about 1.3 VO2max with the contribution of the different energy sources being roughly the same as in top skiers. HR reached maximal values in 30-40 s in all subjects for all conditions.

36. Wilson GD & Sklenka MP (1983): A system for measuring energy cost during highly dynamic activities. J.Sports Med. 2:3, 155-158.

It has been suggested that the widely used portable respirometers (eg Max Planck) might be restrictive in some energy cost measurement situations. Therefore an alternative portable system made up of easily obtainable and inexpensive pieces was designed and compared to the Max Planck during a fastpaced game (raquetball). After play with each system, sixteen subjects were asked to complete a questionnaire relative to how the system affected their movement, their skill performance, and their comfort during play. The newly designed system fared statistically significantly better with respect to both movement and comfort. Thus, it appears that the modified portable system is to be preferred in racquet sport energy cost studies where the movement and comfort limitations of the more commonly used respirometers become significant and restrictive.

37. Zhuo D, Shephard RJ, Plyley MJ & Davis GM (1984): Cardiorespiratory and metabolic responses during Tai Chi Chuan exercise. Can.J.Appl.Sport Sci. 9, 7-10.

Tai Chi Chuan is a form of traditional Chinese exercise which has been widely practiced in China for preventive and therapeutic purposes. The present study was designed to determine the physiological demands of this exercise modality. Eleven healthy males, aged 28.4 years, were studied for oxygen cost and related metabolic variables, heart rate and blood pressure during the performance of the Long-Form Tai Chi Chuan of Yang's style. Data was collected by an automated respiratory gas analyzer (Jeger Ergooxyscreen) and ECG telemetry during a 1725 minute performance session (X = 22 minutes). The average energy cost for the Long-Form Tai Chi Chuan was 4.1 Mets, corresponding to a mean VO2 value of 1.03 I.min-1 or 14.5 ml.kg-1.min-1. The mean peak heart rate during the exercises was 134 beats per minute. These values suggest that the Long-Form Tai Chi Chuan may be classed as moderate exercise, and its intensity does not exceed 50% of the individual's maximum oxygen intake.

4.3.2 Women

1. Abernethy P & Batman P (1994): Oxygen consumption, heart rate and oxygen pulse associated with selected exercise-to-muscle class elements. Br.J.Sports Med. 28, 43-46.

Department of Human Movement Studies, University of Queensland, Brisbane, Australia. The purpose of the investigation was to determine the relative oxygen consumption VO2 heart rate and oxygen pulse associated with the constituent elements of an exercise-to-music class. Six women exercise-to-music leaders with a mean(s.d.) age, weight and height of 33.2(5.2) years, 51.0(2.8) kg and 157.9(5.6) cm respectively, completed five distinct exercise-to-music movement elements. The movement elements were of a locomoter (circuit, jump and low impact) and callisthenic (prone and side/supine) nature. The movement elements were distinguishable from one another in terms of their movement patterns, posture and tempo. Relative VO2 values were greatest for the circuit element (40.6 ml kg-1 min-1) and least for the side/supine element (20.0 ml kg-1 min-1). The differences in VO2 between the locomotor and callisthenic elements were significant (circuit approximately jump approximately low impact > prone approximately side/supine). However, effect size data suggested that the differences between the low impact and jump elements and the prone and side/supine elements were of practical significance (circuit approximately jump > low impact > prone > side/supine). With a single exception similar parametric statistics and effect size trends were identified for absolute heart rate. Specifically, the heart rate associated with the low impact element was not significantly greater than the prone element. The oxygen pulse associated with the locomotor elements was significantly greater than the callisthenic elements (circuit approximately jump approximately low impact > prone > side/supine). This suggested that heart rate may be an inappropriate index for making comparisons between exercise-to-music elements. Reasons for differences in oxygen uptake values between movement elements are discussed.

2. Chatard JC, Lavoie JM & Lacour JR (1991): Energy cost of front-crawl swimming in women. Eur.J.Appl.Physiol 63, 12-16.

Laboratoire de Physiologie, Faculté de Medecine de Saint-Etienne, C. H. R. U . de Saint-Etienne, France. The purpose of this study was to examine the relationship between the energy cost of swimming per unit distance (Cs) at different velocities (v) and performance level, body size and swimming technique in women. A total of 58 females swimmers were studied. Three performance levels (A, B. C) were determined, ranging from the slower (A) to the faster (B. C). At level C and at 1.1 m.s-1, Cs,1.1 was reduced by 7% when directly compared to level B. The Cs,1.1 was reduced by 10% when calculated per unit of height (h) and by 37% when calculated per unit of h and hydrostatic lift (HL). For the whole group of swimmers, the equation regression was Cs,1.1 = 0.27 h-2.38 HL - 7.5 (r = 0.53, P less than 0.01). To evaluate the specific influence of arm length two groups of long- and short-armed swimmers were selected among swimmers of similar h and performance. The Cs was significantly higher (P less than 0.05) by 12%, SD 2.2%, for short-armed than for long-armed swimmers. To evaluate the influence of different types of swimming technique, two other groups of similar performance and anthropometric characteristics were selected. The Cs was significantly higher (P less than 0.05) by 12%, SD 4.5% for swimmers using for preference their legs rather than their arms. The Cs of the sprinters was 15.7%, SD 2% higher than that of the long-distance swimmers. For all groups, Cs increased with v on average by 8% to 11% every 0.1 m.s-1. These findings showed that Cs variations of these women were close to those previously demonstrated for men. The Cs depends on performance level, body size, buoyancy, swimming technique and v.

3. Figura F. Cama G & Guidetti L (1993): Heart rate, alveolar gases and blood lactate during synchronized swimming. J.Sports Sci. 11, 103-107.

Istituto di Fisiologia Umana, Universita La Sapienza, Roma, Italy. Heart rate, alveolar gas partial pressures and blood lactate (BLa) concentration were measured during synchronized swimming in six subjects. During upside-down breath-holding lasting 50 s, heart rate fell progressively from 98 +/- 14 to 70 +/- 7 beats min-1 (mean +/- S.D.). While breath-holding during the compulsory figures, the subjects' heart rate increased to 142 +/- 5 beats min-1 and then fell to 72 +/- 10 beats min-1. At the end of breath-holding, alveolar oxygen pressure had fallen significantly (60 mmHg), whereas alveolar carbon dioxide pressure showed only minor changes (48 mmHg). The increase in BLa concentration due to the execution of compulsory figures was approximately 1 mM; in the free routines, BLa concentration increased by 3.4 +/- 0.5 mM. The net energy cost of completing a compulsory figures lasting 45 s was 34.6 kJ.

4. Nelson DJ, Pels AK, Geenen DL & White TP (1988): Cardiac frequency and caloric cost of aerobic dancing in young women. Res.Q.Exerc.Sport, 59, 229-233.

Our primary purpose was to characterize cardiac frequency during aerobic dancing. A continuous ECG tape recording was obtained on 13 women (21+- .5 yrs; X+- SEM) during aerobic dance classes. The tape was subsequently analyzed by microcomputer for min-by-min heart rate (HR) characteristics. During the main dancing phase of 35 min. the total elapsed time the subjects' HR was greater than or equal to HR reserve thresholds of 60%, 70%, and 80% was 23.9 +- 2.29 min. 17.2 +- 2.75 min. and 9.5 +- 2.24 min. respectively. The longest continuous time that HRs exceeded the minimal threshold of 60% was 17.8 +-2.64 mini this value decreased at the higher threshold of 70% and 80% to 12.4 +- 2.28 and 6.8 +- 1.80 min. respectively. Aerobic dancing can sustain an elevated cardiac frequency, although not all participants demonstrated this response. The caloric cost of aerobic dancing was estimated from HR during dance and the subjects' HR-oxygen consumption relationship determined in the laboratory. The caloric cost during the main dancing phase of the class was estimated to be 8 +- 1.3 kcal/min.

5. Noble L (1975): Heart rate and predicted VO2 during women's competitive gymnastic routines. J.Sports Med. 15, 151-157.

This study attempted to determine the energy expenditure of three highly skilled women gymnasts while participating in competitive optional and compulsory routines on the uneven parallel bars, balance beam, and floor exercise. Activity telemetered heart rates were used to predict VO2 using individual heart rate-VO2 regression lines obtained in the laboratory. The subjects were aged 16, 18 and 22 years. Two subjects were finalists in the 1972 U.S. Junior Olympic competition. Mean maximum VO2 and heart rates of the three subjects were 61.77 ml/kg/min and 184 bpm, respectively. Mean heart rates during performance of the routines ranged from 132 to 176 b/min. Predicted VO2 during performance of the routines ranged from 28.73 to 55.64 ml/kg/mint Optional routines were more strenuous than compulsory routines. Floor exercise routines were most strenuous and routines on the beam were least strenuous.

6. Noble RM & Howley ET (1979): The energy requirement of selected tap dance routines. Res.Q. 50, 438-442.

The primary purpose of this study was to measure the oxygen requirement of two tap dance routines. A secondary purpose was to determine if differences existed between beginning and intermediate tap dance students in the energy requirements for these dance routines. Fifteen female subjects, ranging in age from 17 to 26 years, participated in the study. Eight of the subjects were classified as beginners and seven as intermediates in their ability to tap dance. Each subject performed two tap dance routines, soft shoe and slow buck, to a medley of recorded music of 112 beats per minute (bpm). Expired gas samples were obtained from 2.5 to 3.5 and 3.5 to 4.5 minutes into each routine. There was a short rest period between routines. The mean and standard deviation of oxygen uptake was 16.6 ± 3.1 ml/kg x min for the soft shoe routine and 16.8 + 3.4 ml/kg x min for the buck routine. There was no significant difference between these two routines or between the beginners and intermediates for the energy requirements of either dance routine (p>.05). The above values place tap dancing at 112 bpm at the same intensity as the waltz, foxtrot, rumba, Petronella, and Eightsome Reel.

7. Scharff Olson M, Williford HN, Blessing DL & Greathouse R (1991): The cardiovascular and metabolic effects of bench stepping exercise in females. Med.Sci.Sport Exerc. 23, 1311-1317.

Human Performance Laboratory, Auburn University, Montgomery, AL 36117. The purpose of this investigation was to measure cardiovascular and metabolic responses to 20 min continuous bouts of "choreographed" bench stepping exercise in healthy females. Four frequently used bench heights were employed in E' cross-over design: 15.2 cm (6 inches, B-6), 20.3 cm (8 inches, B-8), 25.4 cm (10 inches, B-10), and 30.5 cm (12 inches, B-12). Oxygen uptake (VO2) responses were significantly more pronounced in direct relationship to the bench height: B-12 >

B-10 > > B-8 > B-6 (P< 0.05). Mean responses for VO2 ranged from 28.4 ml.kg-1.min-1 for B-6 to 37.3 ml.kg-1.min-1 for B-12. Interestingly, no difference was revealed for heart rate and the respiratory exchange ratio between B-12 and B-10 despite a higher VO2 for B-12 (B-12, B-10 > B-8 > B-6, P < 0.05). The incorporation of 0.91 kg (2 lb) hand weights with exercise on the 20.3 cm bench elicited a modest but statistically significant increase in VO2 compared with no hand weights. No significant increase in VO2 was revealed for conditions that employed 0.45 kg (1 lb) hand weights. The results demonstrate that aerobic bench stepping is an exercise modality that provides sufficient cardiorespiratory demand for enhancing aerobic fitness and promoting weight loss in females.

8. Skubic V & Hodgkins J (1966): Energy expenditure of women participants in selected individual sports. .J.Appl.Physiol 21,133-137.

Energy expenditure was determined for two women subjects while exercising on a treadmill. Ventilation, oxygen consumption, and caloric determinations were made when the heart rate reached levels during exercise. The subjects also participated in the playing of five individual type sports and their heart rates were telemetered throughout the activity. Resting and recovery rates were also obtained each day of testing. Regression coefficients for each subject were found showing the relationship between heart rate and ventilation, heart rate and kilocalories, and heart rate and oxygen consumption for work on the treadmill. From these data, estimates were made for the energy cost of game participation as calculated from the known heart rates. The various calculations indicated that badminton and tennis are significantly more strenuous than golf, bowling, and archery, and that golf and archery are more strenuous than bowling. According to available classifications on energy cost, badminton and tennis were rated as moderate activities and golf, bowling, and archery were rated as mild activities.

9. Williford HN, Blessing DL, Olson MS & Smith FH (1989): Is low-impact aerobic dance an effective cardiovascular workout? Physician Sportsmed. 16, 95-109.

Ten women performed four different aerobic dance routines in a randomized crossover study to evaluate energy expenditure. The routines consisted of the following combinations: low intensity, low impact; high intensity, low impact; low intensity high impact; and high intensity and high impact. The women warmed up for five minutes, then did a 20-minute routine. Metabolic measures were monitored by means of open circuit spirometry and heart rates measured by ECG. Statistical analyses showed that for both high and low intensities, the high-impact routines. required a significantly greater energy expenditure, regardless of heart rate. Thus for low-impact dance to meet the minimum guidelines for exercise suggested by the American College of Sports Medicine, it should be performed at high intensity.

4.3.3 Men & women

1. Adams WC (1967): Influence of age, sex, and body weight on the energy expenditure of bicycle riding. .J.Appl.Physiol 22, 539 545

Energy expenditure observations were made on 60 normal adult men and women, ranging in age from 20 to 52.2 years, while riding a narrow-tire bicycle at a previously determined average speed. Analysis of variance indicated that age had no effect on gross energy expenditure and that, when the latter was divided total body weight, there was no significant difference between men and women. The results of multiple regression analysis confirmed the dominant effect of total body weight, in that neither the addition of age, height, body surface area, lean body weight, fat body weight, or tricep skinfold contributed significantly to the prediction of energy expenditure for the ride.

2. Bergh U (1987): The influence of body mass in cross-country skiing. Med.Sci.Sport Exerc. 19, 324-331.

National Defense Research Institute, Environmental Stress and Human Performance, Stockholm, Sweden. The influence of body weight on the performance in cross-country skiing has been studied by: dimensional analysis of the ratio (R) between the factors of importance to power production VO2max acceleration of gravity) and the braking powers, e.g., friction and air resistance; measuring the energy cost of level skiing (N = 6); comparing male world class skiers (N = 5) with less successful ones (N = 34) and female winners of the National Championships (N = 9) with non-winners (N = 9) in regard to the relationship between body weight and VO2max The dimensional analysis revealed that R was less than unity for rather steep uphills. For level, downhill, and less steep uphill skiing, R was greater than unity. Thus, skiers who are light will be favored in steep uphill slopes, whereas heavier skiers have advantages in the other parts of the track. Energy cost per kilogram for level skiing was inversely related to the transported mass. Per unit of distance, this cost was positively related to velocity. The world class skiers displayed significantly greater VO2max than the less successful ones, regardless of the unit used. The lowest standard deviation among the world class skiers was attained when expressing VO2max as ml X min-1 X kg-2/3. The present results indicate that R will be quite close to unity and therefore the performance capability would theoretically be independent of body mass. Furthermore, VO2max is preferably expressed as ml X min-1 X kg-2/3 for cross-country skiers.

3. Blanksby BA & Reidy PW (1988): Heart rate and estimated energy expenditure during ballroom dancing. Br.J.Sports Med. 22, 57-60.

Department of Human Movement and Recreation Studies, University of Western Australia, Nedlands. Ten competitive ballroom dance couples performed simulated competitive sequences of Modern and Latin American dance. Heart rate was telemetered during the dance sequences and related to direct measures of oxygen uptake and heart rate obtained while walking on a treadmill. Linear regression was employed to estimate gross and net energy expenditures of the dance sequences. A multivariate analysis of variance with repeated measures on the dance factor was applied to the data to test for interaction and main effects on the sex and dance factors. Overall mean heart rate values for the Modern dance sequence were 170 beats.min-1 and 173 beats.min1 for males and females respectively. During the Latin American sequence mean overall heart rate for males was 168 beats.min-1 and 177 beats.min1 for females. Predicted mean gross values of oxygen consumption for the males were 42.8 +/-5.7 ml.kg-1 min-1 and 42.8 +/- 6.9 ml.kg-1 min-1 for the Modern and Latin American sequences respectively. Corresponding gross estimates of oxygen consumption for the females were 34.7 +/- 3.8 ml.kg-1 min-1 and 36.1 +/- 4.1 ml.kg-1 min-1. Males were estimated to expend 54.1 +/-8.1 kJ.min-1 of energy during the Modern sequence and 54.0 +/-9.6 kJ.min-1 during the Latin American sequence, while predicted energy expenditure for females was 34.7 +/- 3.8 kJ.min-1 and 36.1 +/- 4.1 kJ.min-1 for Modern and Latin American dance respectively. The results suggested that both males and females were dancing at greater than 80% of their maximum oxygen consumption. A significant difference between males and females was observed for predicted gross and net values of oxygen consumption (in L.min-1 and ml.kg-1 min-1).

4. Bransford DR & Howley ET (1977): Oxygen cost of running in trained and untrained men and women. Med.Sci.Sport Exerc. 9, 41-44.

The purpose of this study was to compare the oxygen cost of running as it relates to speed of running among the following four groups: trained male distance runners, trained female distance runners, untrained but active men and women. Each subject was given a series of treadmill tests during which Vo2 was measured at submaximal work loads. The linear regression equation was utilized to compute the relationship between Vo2 and running speed for each groups. The results indicated that the rate of increase in Vo2 for a given increase in running speed could be represented as a straight line and was the same for all groups (P greater than .05). The trained male runners had a significantly lower Vo2 (P less than .05) than those of the other three groups at any measured speed. The trained females and untrained males had significantly lower Vo2s than the untrained females (P less than .05) at any of the given range of speeds. No significant differences were observed between the untrained mean and trained women (P greater than .05). It was concluded that there were differences in the oxygen cost of running not only between the trained and untrained groups but also between males and females.

5. Brehm BA & Gutin B (1986): Recovery energy expenditure for steady state exercise in runners and nonexercisers. Med.Sci.Sport Exerc. 18, 205-210.

This study examined the effects of intensity, mode of exercise, and aerobic fitness on the energy expended during recovery (recovery oxygen consumption, or rec VO2 following steady state exercise. Eight runners (4 mares, 4 females; 22-32 yr) walked at 3.2 and 6.4 km X h-1 and ran at 8.1 and 11.3 km X h-1 (18, 33, 50, and 68% peak VO2 All subjects completed 3.2 km of walking or running each session. Eight sedentary adults (4 male, 4 female; 21-33 yr) completed the 6.4 km X h-1 test. For the runners, net rec VO2 for 3.2, 6.4, 8.1 and 11.3 km X h-1 exercise was (X +/-SE) 12.52 +/- 3.00, 29.53 +/- 5.41, 28.64 +/- 2.91, and 44.27 +/-5.32 ml X kg-1, respectively, for the recovery period (18-48 min). Differences among group means were significant (P less than 0.05), except between 6.4 and 8.1 km X h-1 walking (29.53 +/-5.41 and 35.09 +/- 9.39 ml X kg-1). Statements attributing substantial energy expenditure to the recovery period may be misleading to people exercising at levels similar to those described in this study, since the recovery energy expenditure only amounted to approximately 13-71 kJ (3-17 kcal).

6. Bunc V & Heller J (1989): Energy cost of running in similarly trained men and women. Eur.J.Appl.Physiol 59, 178-183.

Physical Culture Research Institute, Charles University, Prague 1, Czechoslovakia. The energy demand of running on a treadmill was studied in different groups of trained athletes of both sexes. We have not found any significant differences in the net energy cost (C) during running (expressed in J.kg-1.m-1) between similarly trained groups of men and women. For men and women respectively in adult middle distance runners C = 3.57 +/- 0.15 and 3.65 +/-0.20, in adult long-distance runners C = 3.63 +/- 0.18 and 3.70 +/- 0.21, in adult canoeists C = 3.82 +/- 0.34 and 3.80 +/- 0.24, in young middle-distance runners C = 3.84 +/- 0.18 and 3.78 +/-0.26 and in young long-distance runners C = 3.85 +/- 0.12 and 3.80 +/- 0.24. This similarity may be explained by the similar training states of both sexes, resulting from the intense training which did not differ in its relative intensity and frequency between the groups of men and women. A negative relationship was found between the energy cost of running and maximal oxygen uptake (VO2max) expressed relative to body weight (for men r = -0.471, p less than 0.001; for women r = -0.589, p less than 0.001). In contrast, no significant relationship was found in either sex between the energy cost of running and VO2max. We conclude therefore that differences in sports performance between similarly trained men and women are related to differences in VO2max.kg-1. The evaluation of C as an additional characteristic during laboratory tests may help us to ascertain, along with other parameters, not only the effectiveness of the training procedure, but also to evaluate the technique performed.

7. Burke EJ & Keenan TJ (1984): Energy cost, heart rate, and perceived exertion during the elementary backstroke. Physician Sportsmed. 12, 75-80.

The purpose of this study was to determine the energy cost of the elementary backstroke and to see if heart rate and perceived exertion are useful for monitoring exercise intensity. Five healthy men and five healthy women swam the elementary backstroke at four different intensities, and velocity, VO2 heart rate, and perceived exertion were monitored. Each dependent variable significantly increased with increasing intensity. The only sex difference was a higher VO2 in men for each work intensity. Average energy cost ranged from 0.097 kcal.kg^-1.min^-1 at 1.1 to 1.4 km.hr^-1 to 0.17 kcal.kg^-1.min^-1 at 1.8 to 2.0 km.hr^-1 (SEM + - 0.01). It was concluded that the elementary backstroke is suitable for a fitness program.

8. Capelli C, Zamparo P. Cigalotto A, Francescato MP, Soule RG, Termin B. Pendergast DR & di Prampero PE (1995): Bioenergetics and biomechanics of front crawl swimming. .J.Appl.Physiol 78, 674-679.

Dipartimento di Scienze e Tecnologie Biomediche, Universita di Udine, Italy. "Underwater torque" (T') is one of the main factors determining the energy cost of front crawl swimming per unit distance (Cs). In turn, T' is defined as the product of the force with which the swimmer's feet tend to sink times the distance between the feet and the center of volume of the lungs. The dependency of Cs on T' was further investigated by determining Cs in a group of 10 recreational swimmers (G1: 4 women and 6 men) and in a group of 8 male elite swimmers (G2) after T' was experimentally modified. This was achieved by securing around the swimmers' waist a plastic tube filled, on different occasions, with air, water, or 1 or 2 kg of lead. Thus, T' was either decreased, unchanged, or increased compared with the natural condition (tube filled with water). Cs was determined, for each T' configuration, at 0.7 m/s for G1 and at 1.0 and 1.2 m/s for G2. For T' equal to the natural value, Cs (in kJ.m-1.m body surface area-2) was 0.36 +/-0.09 and 0.53 +/0.13 for G1 in women and men, respectively, and 0.45 +/- 0.05 and 0.53 +/- 0.06 for G2 at 1.0 and 1.2 m/s, respectively. In a given subject at a given speed, Cs and T' were linearly correlated. To compare different subjects and different speeds, the single values of Cs and T' were normalized by dividing them by the corresponding individual averages. These were calculated from all single values (of Cs or T') obtained from that subject at that speed. The normalized Cs was found to be a linear function of the normalized T' (r=0.84, P<0.001; n-86) regardless of sex, speed, or swimming skill. We concluded that, in the speed range of 0.7-1.23 m/s, T' is indeed the main determinant of Cs regardless of sex or swimming skill.

9. Cohen JL, Segal KR, Witriol I & McArdle WD (1982): Cardiorespiratory responses to ballet exercise and the VO2max of elite ballet dancers. Med.Sci.Sport Exerc. 14, 212-217.

Physiologic responses to ballet exercise and VO2max during treadmill running were studied in elite professional ballet dancers (7 men, 8 women; age 20-30 yr) from the American Ballet Theatre. Ten dancers were studied during standard 1-h ballet classes consisting of 28 min of barre and 32 min of center floor exercise. Eight dancers performed maximal treadmill running tests yielding VO2max values (ml . min-1 . kg-1) of 48.2 (range 43.8-51.9) for men and 43.7 (range 40.9-50.1) for women. Mean VO2 (ml . min-1 . kg-1) during barre exercise was 18.5 (38% VO2max) for men and 16.5 (38% VO2max) for women; during center floor exercise 26.3 (55% VO2max) for men and 20.1 (46% VO2max) for women, with a peak of 77% VO2max for a male dancer. Mean caloric output values (kcal . kg-1 . min-1) during barre exercise were 0.09 and 0.08 for men and women, respectively, and during center floor exercise 0.13 for men and 0.10 for women, with a peak of 0.18 for one male dancer. Estimated net caloric outputs for the entire ballet class averaged 200 kcal . h-1 for women and 300 kcal . h-1 for men. During barre exercise, HR was below the training sensitive zone (70% HR max) for significant periods of time. Peak HR (beats . min-1) was relatively high during allegro center floor exercise, averaging 178 (92% HR max) and 158 (85% HR max) for men and women, respectively. However, these were maintained for only brief durations similar to sprint or burst activities. We conclude that these physiologic data obtained during ballet class represent only a relatively modest stimulus for augmenting aerobic (VO2max). In conjunction with the strong isometric component in ballet exercise, along with the sprint or burst component of ballet exercise, these factors would produce in elite ballet dancers VO2max values in the range of non-endurance athletes.

10. Holmer I (1972): Oxygen uptake during swimming in man. .J.Appl.Physiol 33, 502-509.

It is possible to set the water flow rate with great accuracy in a recently constructed swimming flume, i.e., a kind of swimming "treadmill". Oxygen uptake, heart rate, and blood lactate concentrations were measured in three female and six male adult subject, with varying proficiency in swimming, while subjects swam three styles at different speeds. The same determinations were made during exercise on a Krogh bicycle ergometer and on a treadmill. The same determinations were made in 12 girl swimmers, 13-18 years old, but only during maximal running and maximal swimming. Minimal oxygen uptake during floating in a vertical position in nine subjects varied from 0.9 to 2.0 I.min^-1. At a given swimming speed the trained swimmers were able to swim with a much lower oxygen uptake than subjects who were not trained swimmers. At a given oxygen uptake trained swimmers also swam much faster than the untrained swimmers. The front crawl proved to be the most economical style, as is the case in competition swimming. The back crawl was somewhat less economical and the breaststroke was the least economical style. Maximal oxygen uptake, maximal pulmonary ventilation, and maximal heart rate were significantly lower in swimming than in running or cycling, respectively.

11. Howley ET & Glover ME (1974): The caloric costs of running and walking one mile for men and women. Med.Sci.Sport Exerc. 6, 235-237.

Our purpose was to resolve the disagreement as to the number of calories expended per unit distance for walking and running. The caloric costs of walking and running one mile on a treadmill were calculated for eight men and eight women. The subjects walked at a speed of 82 +3 m/min (X+- SD) and ran at a speed that was regarded subjectively as comfortable. The average speed at which the mile was run was 195 +- 25 m/min for men and 137 +- 4 m/min for women. The average R measured during the walk was 0.86 and during the run 0.96. The gross caloric cost of walking was 1.08 +- 0.06 kcal/kg per mile for men and 1.15 +-0.08 kcal/kg per mile for women, and the cost of running was 1.57 +- 0.09 kcal/kg per mile for men and 1.73 +0.09 kcal/kg per mile for women. The running required significantly more kcal/kg per mile than walking (P<0.001) and the women used significantly more calories for both running and walking compared to the men (P<0.01). The net caloric cost of walking was 0.76 +- 0.07 kcal/kg per mile for men and 0.83 +- 0.08 kcal/kg per mile for women, and the cost of running was 1.43 +-0.08 kcal/kg per mile for men and 1.53 +- 0.09 kcal/kg per mile for women. The difference between the run and walk was highly significant (P<0.001) and the women used significantly more calories than men for both activities (P<0.05). Possible reasons for the small but statistically significant difference between men and women are discussed. It was concluded that running a given distance required more calories than walking the same distance.

12. Igbanugo V & Gutin B (1978): The energy cost of aerobic dancing. Res.Q. 49, 308-316.

The energy cost of three intensities of aerobic dance (low, medium, and high) was determined on four graduate students at Teachers College, Columbia University. All subjects danced seven 2-to 3-minute routines alternated with six 15- to 90-second recovery intervals of continuous walking. The dances were metabolically monitored with a Max Planck respirometer which measured ventilation and collected .06% sample of expired air, which was then analyzed for 02 and CO2 concentration. Values were expressed as VO2 I/minute, VO2 ml/kg/minute, and energy consumption as kcal/minute, and kcal/kg/minute. Heart rates were monitored by telemetry every minute throughout the dance. The women utilized 3.96 kcal/minute, 6.28 kcal/minute, and 7.75 kcal/minute, for the low, medium, and high intensity routines, respectively, while the men utilized 4.17 kcal/minute, 6.86 kcal/minute, and 9.44 kcal/minute, respectively. The energy expenditure for the low intensity routine was metabolically similar to walking on the level, that of the medium intensity routine to playing tennis, and that of the high intensity to playing hockey. Mean heart rates were 114, 145, and 156 beats per minute (bpm) for women; 106, 129, and 141 bpm for men. On the basis of these results, it is concluded that aerobic dance can be useful as a modality for cardiorespiratory training and rehabilitation, as well as weight reduction and maintenance.

13. Jette M & Inglis H (1975): Energy cost of square dancing. .J.Appl.Physiol 38, 44-45.

This experiment was concerned with determining the energy cost of two popular Western square dancing routines: the "Mish-Mash," which is a relatively fast-moving dance with quick movements, and the "Singing" dance, which is a slower and more deliberate type of dance. The subjects were four middle-aged couples, veteran members of a local square dancing club. Sitting and standing pulmonary ventilations were determined through the use of the Tissot gasometer. Kofranyi-Michaelis respirometers were employed for the dance routine ventilations.

These apparatus were fitted with a Monoghan neoprene cushion plastic mask. Gas samples were collected in polyethylene metallized bags and analyzed for O2 and CO2 content. The net energy cost for the two dances was appropriately summarized. The results indicated that for the males the net average energy cost of the Mish-Mash dance was 0.085 and 0.077 kcal/min per kg for the Singing dance. For the females, the cost was 0.088 and 0.084 kcal/min per kg, respectively. A net average cost of these two dances yielded a caloric expenditure of 5.7 kcal/min for a 70-kg male and 5.2 kcal/min for a 60-kg female. It was indicated that during the course of a typical square dance evening, a 70-kg man would expend some 425 kcal. while a 60-kg female would burn some 390 kcal. The energy cost of the dances studied were determined to be within the permissible work load of a functional class 1 patient with diseases of the heart as determined by the American Heart Association.

14. Jing L & Wenyu Y (1991): The energy expenditure and nutritional status of college students. I The energy cost and the total energy expenditure per day. Biomed.Environ.Sci. 4, 295-303.

The energy cost of major activities was determined in healthy students. Among the 606 medical students, 319 were males and 287 were females. Their ages ranged from 18 to 24 years. Douglas method was used to measure energy cost of each of a total of 42 activities, as well as that of the basal metabolic rates (BMR), resting metabolic rates (RMR) and the total energy expenditure per day under normal situations. The average RMR of male and female subjects were 0.669 +- 0.033 and 0.656 +- 0.030 kcal/sq.m/min respectively. The total energy expenditure per day of male students was 2706 kcal, and 2373 kcal for female students. The energy cost of single activities can be used as the basal data in studies of energy metabolism.

15. Lampley JH, Lampley PM & Howley ET (1977): Caloric cost of playing golf. Res.Q. 48, 637639.

The caloric cost of playing golf was measured in 11 men and 11 women. All subjects played the same nine holes and pulled a golf cart weighing approximately 14.kg. Expired air was collected for 15 seconds each minute during play, but no gas collections were made during a full swing due to limitations of the equipment. The measured energy costs were 4.2 + 0.6 kcal/kg/hr for men and 4.8 ± kcal/kg/hr for women, which was significantly higher (p < 0.05). These values are consistent with energy costs of playing golf reported by other investigators when expressed as net energy costs for 18 holes of golf.

16. Leger LA (1982): Energy cost of disco dancing. Res.Q.Exerc.Sport, 53, 46-49.

The purpose of this study was to evaluate the energy cost of dancing in the conditions that prevail in disco clubs. To avoid any hindrance in the movements of the dancers, oxygen uptake was assessed by retroextrapolating the O2 recovery curve to time zero of recovery. Males and females required a similar energy cost for disco dancing, that is 30.1 +- 10.3 ml O2.kg^-1.min^-1 for a fundamental music rhythm of 135.0 +- 7.7 bpm (X +- SD = for 15 university students). Males, being heavier than females, have a higher absolute energy expenditure (X +- SD = 48.5 +- 15.2 and 31.7 +- 13.7 kJ.min^-1). Heart rate was 134.5 +- 13.4 bpm. Total energy expenditure for a dancing evening (90 min of active time) was estimated to be 4350 and 2850 kJ for the males and the females respectively. At approximately 60 and 70% VO2 max for males and females respectively, disco dancing could be efficient for improving aerobic fitness and for controlling excess body fat. In this respect, and from the literature, disco dancing (rock and roll, hustle, twist, disco) appears almost twice as strenuous as square dancing and most other traditional dances (rumba, fox trot, waltz). The above figures are averages, and intra-individual variations of 3.0 ml.kg-1.min-1 (average difference between two trials) and inter-individual variations of 10.3 ml.kg1.min-1 (standard deviation) suggest caution before applying the average scores to any individual. Results reported above did not appear to be affected by the music rhythm, at least not for the range observed in this study (120-150 bpm). Indeed the energy cost of dancing on two music rhythms (128.0 +-8.9 and 140.0 +- 9.8 bpm) was not significantly different; furthermore, the correlation between the rhythm and the oxygen uptake was only r= 0.1.

17. Leger L & Mercier D (1984): Gross energy cost of horizontal treadmill and track running. Sports Med. 1, 270-277.

The gross energy cost of treadmill and track running is re-investigated from data published in the literature. An average equation, weighted for the number of subjects in each study, was found: VO2 (ml/kg/min) = 2.209 + 3.163 speed (km/h) for 130 subjects (trained and untrained males and females) and 10 treadmill studies. On the track, wind resistance as predicted by Pugh (1970) was added to the treadmill cost of running and yielded the following equation for adults of average weight and height: VO2 = 2.209 + 3.163 speed + 0.000525542 speed. Between 8 and 25 km/in, the following linear equation: VO2 = 3.5 speed (or met = km/in) was very close to the cubic equation. This linear equation for track running is, however, different from the treadmill linear equation, particularly for speeds over 15 km/in. This equation is also slightly different from the one published by Pugh (1970) for track running from 7 trained subjects only.

18. Maughan RJ & Leiper JB (1983): Aerobic capacity and fractional utilisation of aerobic capacity in elite and non-elite male and female marathon runners. Eur. J.Appl.Physiol 52, 80-87. The physiology of marathon running has been extensively studied both in the laboratory and in the field, but these investigations have been confined to elite competitors. In the present study 28 competitors who took part in a marathon race (42.2 km) have been studied; 18 male subjects recorded times from 2 h 19 min 58 s to 4 h 53 min 23 s; 10 female subjects recorded times between 2 h 53 min 4 s and 5 h 16 min 1 s. Subjects visited the laboratory 2-3 weeks after the race and ran on a motor driven treadmill at a series of speeds and inclines; oxygen uptake VO2 was measured during running at average marathon racing pace. Maximum oxygen uptake VO2 max) was measured during uphill running. For both males (r = 0.88) and females (r = 0.63), linear relationships were found to exist between marathon performance and aerobic capacity. Similarly, the fraction of VO2 max which was sustained throughout the race was significantly correlated with performance for both male (r = 0.74) and female (r = 0.73) runners. The fastest runners were running at a speed requiring approximately 75% of VO2 maxi for the slowest runners, the work load corresponded to approximately 60% of VO2 max. Correction of these estimates for the additional effort involved in overcoming air resistance, and in running on uneven terrain will substantially increase the oxygen requirement for the faster runners, while having a much smaller effect on the work rate of the slowest competitors. Five minutes of treadmill running at average racing pace at zero gradient did not result in marked elevation of the blood lactate concentration in any of the subjects.

19. Mayhew JL, Piper FC & Etheridge GL (1979): Oxygen cost and energy requirement of running in trained and untrained males and females. J.Sports Med. 19, 39-44.

The oxygen cost and energy requirement of submaximal treadmill running was assessed on trained (n=1) males and trained (n=5) and untrained (n=6) females. Open circuit spirometry was used to determine each subject's oxygen consumption during the final 2 minutes of 5-minute runs at 135, 150, 165, and 180 m/mint Two-way ANOVA was used to determine differences across speeds and subjects. Submaximal VO2 (ml/kg/min) was not significantly different among the four groups. Trained subjects, however, showed slightly greater efficiency than their untrained counterparts (5%). The VO2-running speed relationships were linear for all groups. Regression slopes and intercepts were not significantly different. Untrained females expended significantly more relative energy (kcal/kg/km) than untrained males, but no more than the two trained groups. The reason for this was perhaps a combination of greater relative fat content and inefficient running mechanics of the untrained females.

20. Padilla S. Bourdin M, Barthelemy JC & Lacour JR (1992): Physiological correlates of middle-distance running performance. A comparative study between men and women. Eur.J.Appl.Physiol 65, 561-566.

Centro Medicina Deportiva, Neudigonoza Amadeo Garcia Salazar S/U, Victoria-Gasteiz, Spain. To compare the relative contributions of their functional capacities to performance in relation to sex, two groups of middle-distance runners (24 men and 14 women) were selected on the basis of performances over 1500-m and 3000-m running races. To be selected for the study, the average running velocity (v) in relation to performances had to be superior to a percentage (90% for men and 88% for women) of the best French v achieved during the season by an athlete of the same sex. Maximal 02 consumption VO2max and energy cost of running (CR) were measured in the 2 months preceding the track season. This allowed us to calculate the maximal v that could be sustained under aerobic conditions, va,max. A v:va,max ratio derived from 1500-m to 3000-m races was used to calculate the maximal duration of a competitive race for which v = va,max (tva,max). In both groups va,max was correlated to v. The relationships calculated for each distance were similar in both sexes. The CR [0.179 (SD 0.010) ml.kg-1 x m-1 in the women versus 0.177 (SD 0.010) in the men] and tva,max [7.0 (SD 2.0) min versus 8.4 (SD 2.1)] also showed no difference. The relationships between VO2max and body mass (mb) calculated in the men and the women were different. At the same mb the women had a 10% lower CR than the men; their lower mb thus resulted in an identical CR. In both groups CR and VO2max were strongly correlated (r=0.74 and 0.75 respectively, P < 0.01), suggesting that a high level of VO2max could hardly be associated with a low CR. These relationships were different in the two groups (P < 0.05). At the same VO2max the men had a higher va,max than the women. Thus, the disparity in track performances between the two sexes could be attributed to VO2max and to VO2max/Cr relationships.

21. Pendergast DR, Bushnell D, Wilson DW & Cerretelli P (1989): Energetics of kayaking. Eur.J.Appl.Physiol 59, 342-350.

Department of Physiology, State University of New York at Buffalo 14214. The metabolic cost of paddling at low speeds (v) was measured from oxygen uptake VO2 and anaerobic glycolysis in an annular pool or calculated from submaximal VO2 measured at higher speeds when the kayaker was assisted in overcoming water resistance. Also calculated were the total drag (D) and the net mechanical efficiency (e). Each of the above variables was determined in male (n = 17) and female (n = 7) kayakers ranging in experience from beginners to elite. The VO2 increased with v to a peak of approximately 3.4 I.min-1 (80%-100% of peak VO2 during running) in men and of approximately 2.8 I.min-1 in women, while at higher speeds the additional energy was accounted for by anaerobic glycolysis. In all subjects the energy cost to paddle a given distance (C) increased according to a power function with increasing v. The C was lower for the elite male paddlers than for the unskilled group, while that for elite women was slightly less than that for the elite men. Also the rates of increase of C appeared to be inversely proportional to the subjects' skill. Total D for elite men increased from approximately 15 to 60 N over a range of speeds from 1 to 2.2 m.s-1 while those of unskilled men and skilled women for the same speed range were 10-20 N greater and slightly less, respectively. The e increased linearly, but at a different rate, with increases in v for the unskilled and the elite kayakers (males and females) being 4.2% and 6%, respectively, at v = 1.2 m.s-1.

22. Pendergast DR, di Prampero PE, Craig ABJ, Jr., Wilson DR & Rennie DW (1977): Quantitative analysis of the front crawl in men and women. .J.Appl.Physiol 43, 475-479.

Body drag, D, and the overall mechanical efficiency of swimming, e, were measured from the relationship between extra oxygen consumption and extra drag loads in 42 male and 22 female competitive swimmers using the front crawl at speeds ranging from 0.4 to 1.2 m/s. D increased from 3.4 (1.9) kg at 0.5 m/s to 8.2 (7.0) kg at 1.2 m/s, with D of women (in brackets) being significantly less (P < 0.05) than that of men. Mechanical efficiency increased from 2.9% at 0.5 m/s to 7.4% at 1.2 m/s for men, the values for women being somewhat greater than those for men. The ratio D/e was shown to be identical to the directly measured energy cost of swimming one unit distance, V02/d, and was independent of the velocity up to 1.2 m/s. It averaged 52 and 37 I/km for men and women respectively (P < 0.05). When corrected for body surface area the values were 27 and 22 I/km-m2 for men and women, respectively (P < 0.05). The underwater torque, T. a measure of the tendency of the feet to sink, was 1.44 kg-m for men and 0.70 kg-m for women (P less than 0.05). VO2/d increased linearly with T for both men and women of similar competitive experience. However, the proportionality constant delta VO2/d-delta T was significantly less for competitive than noncompetitive swimmers. The analysis of the relationship VO2/d vs. T provides a valuable approach to the understanding of the energetics of swimming.

23. Schantz PG & Astrand P (1984): Physiological characteristics of classical ballet. Med.Sci.Sport Exerc. 16,472-476.

The aerobic and anaerobic energy yield during professional training sessions ("classes") of classical ballet as well as during rehearsed and performed ballets has been studied by means of oxygen uptake, heart rate, and blood lactate concentration determinations on professional ballet dancers from the Royal Swedish Ballet in Stockholm. The measured oxygen uptake during six different normal classes at the theatre averaged about 35-45% of the maximal oxygen uptake, and the blood lactate concentration averaged 3 mM (N = 6). During 10 different solo parts of choreographed dance (median length = 1.8 min) representative for moderately to very strenuous dance, an average oxygen uptake (measured during the last minute) of 80% of maximum and blood lactate concentration of 10 mM was measured (N = 10). In addition, heart rate registrations from soloists in different ballets during performance and final rehearsals frequently indicated a high oxygen uptake relative to maximum and an average blood lactate concentration of 11 mM (N = 5). Maximal oxygen uptake, determined in 1971 (N = 11) and 1983 (N = 13) in two different groups of dancers, amounted to on the average 51 and 56 ml.min-1.kg-1 for the females and males, respectively. In conclusion, classical ballet is a predominantly intermittent type of exercise. In choreographed dance each exercise period usually lasts only a few minutes, but can be very demanding energetically, while during the dancers' basic training sessions, the energy yield is low.

24. Seliger V (1969): Energy expenditures during paddling. Physiologia Bohermoslovaka, 18, 4955.

Energy metabolism was assessed in 16 students of the Faculty of Physical Education during paddling in canoe-doubles on a tourist laminate canoe on a 1000m course. A similar examination was performed on 13 men and 13 women of the first grade during paddling in kayak-singles on a 500m course. In spite of the fact that the activity does not concern the whole body musculature, energy expenditure in canoeists was 9.7, and for paddling in kayaks was 33.8 in men and 16.6 kcal/min in women. The oxygen debt was 8.2 litres in men for kayak racing, which indicates the important role of anaerobic metabolism. This value was somewhat lower in women (4.5 litres). In canoeists the oxygen debt was 3.8 litres and this shows the greater anaerobic component of this performance. The pulse rate and especially the minute ventilation increases in kayak paddling almost to maximum values. It appears from these results that during training for high speed canoe paddling more attention should be paid to the development of the anaerobic capacity of the organism.

25. Snyder AC, O'Hagan KP, Clifford PS, Hoffman MD & Foster C (1993): Exercise responses to in-line skating: comparisons to running and cycling. Int.J.Sports Med. 14, 38-42.

Department of Human Kinetics, University of Wisconsin, Milwaukee 53201. A comparison of the physiological responses to in-line skating with the more traditional modes of exercise training has not been reported. The purpose of this study was to examine the physiological responses to inline skating compared with running and cycling. Nine trained volunteers (2 male, 7 female) performed 3-6 submaximal (30-90% VO2max workloads with each exercise mode. Oxygen uptake, heart rate and blood lactate were measured during each trial. Across the spectrum of oxygen uptakes studied, heart rate was higher with in-line skating than with cycling or running. At a lactate concentration of 4 mM, oxygen uptake was less for in-line skating and cycling than for running. Therefore, while in-line skating may be an effective mode of aerobic exercise, the training adaptations for in-line skating at 4 mM lactate may not be as great as for running, and at a given HR may be less than for running and cycling.

26. Toussaint HM, Knops W. de Groot G & Hollander AP (1990): The mechanical efficiency of front crawl swimming. Med.Sci.Sport Exerc. 22, 402-408.

Department of Exercise Physiology and Health, Faculty of Human Movement Sciences, Vrije Universiteit, Amsterdam, The Netherlands. In this study the gross efficiency of swimming was determined in a group of male (N = 6) and female (N = 4) competitive swimmers. The gross efficiency is defined as the ratio of the power output (W) to the power input (W). In a range of swimming velocities (0.95-1.6 m.s-1), the power input (rate of energy expenditure, 445-1137 W) was calculated from the oxygen uptake values (1.33-3.25 1 O2.min-1). The total power output (26-108 W) was directly measured during front crawl swimming using a system of underwater push-off pads instrumented with a force transducer (MAD-system). Using the MAD-system, the effect on total body drag due to the addition of the respiratory apparatus was evaluated to be negligible. The gross efficiency ranged from 5 to 9.5%. At equal swimming speed, the male competitive swimmers demonstrated a higher gross efficiency. However, this was due to the higher power output required by the male swimmers at a given speed. Gross efficiency was dependent on the absolute power output such that as power output increased so did the calculated gross efficiency. At the same power output, the values for the gross efficiency do not differ between the male and female competitive swimmers.

27. van Baak MA & Binkhorst RA (1981): Oxygen consumption during outdoor recreational cycling. Ergonomics, 24, 725-733.

The relation between oxygen consumption and cycling speed during outdoor recreational cycling was studied in 20 healthy subjects, men and women aged 20-30 and 50-60 years. They rode a touring bicycle at speeds between 2.8 and 8.3 m/s (10 and 30 km/hr). No significant differences in oxygen consumption were found between the sexes and two age groups. The scatter of the oxygen consumption data was least when oxygen consumption was expressed in terms of body surface. Different types of equations were developed for the prediction of oxygen consumption from the cycling speed which all gave approximately equally accurate predictions (VO2=0.137+0.0248V²; VO2=0.379-0.102V+0.0346V²; VO2=0.103V+0.00103V³; VO2 is oxygen consumption in l/min/m², V is cycling speed in m/s). The equation may also be applied for cycling in traffic situations if the mean speed is corrected for stop times.

28. Wigaeus E & Kilbom A (1980): Physical demands during folk dancing. Eur.J.Appl.Physiol 45, 177-183.

This investigation was undertaken to evaluate the aerobic demands during one of the most popular and demanding Swedish folk dances, the "hambo". Six men and six women, ranging in age from 22 to 32, participated. Their physical work capacity was investigated on a bicycle ergometer and a treadmill, using two to three submaximal and one maximal loads. All subjects were moderately well-trained and their average maximal oxygen uptakes on the treadmill were 2.5 and 3.7 I/min (42.8 and 53.2 ml/kg.min-1) for women and men, respectively. When dancing the "hambo" the heart rate was telemetered, and the Douglas bag technique was used for measurements of pulmonary ventilation and oxygen uptake. The physical demand during "hambo" dancing was high in all subjects. Oxygen uptake was 38.5 and 37.3 ml/kg.min-1 and heart rate 179 and 172 in women and men, respectively. Women used 90% and men 70% of their maximal aerobic power obtained on the treadmill. The pulmonary ventilation and respiratory quotient of the female subjects were lower when dancing as compared to running, possibly because of voluntary restriction of the movements of the thoracic cage. Some popular Scandinavian folk dances are performed at a speed and with an activity pattern resembling the "hambo", while others are performed at a slower pace. The exercise intensity used in "hambo" is more than sufficient to induce training effects in the average individual provided that the dancing is performed at the frequency and for length of time usually recommended for physical training. For older or less fit people dances with a slow pace can be used for training purposes.

29. Wilmore JH, Parr RB, Ward P. Vodak PA, Barstow TJ, Pipes TV, Grimditch G & Leslie P (1978): Energy cost of circuit weigh: training. Med.Sci.Sport Exerc. 10, 75-78.

The metabolic cost of circuit weight training was determined in a group of 20 men and 20 women, 17 to 36 years of age, who volunteered to participate in this study. Performing 3 circuits (10 stations/circuit), using a work (30-see) to rest (15-see) ratio of 2:1, and a total exercise time of 22.5 min. the energy expenditure was found to be highly related to body weight (r = 0.84 and r = 0.67 for men and women respectively). The average gross energy expenditure was 539.7 and 367.5 kcal/hr. (9.0 and 6.1 kcal/min) for the men and women respectively, but was 7.0 and 6.0 kcal/kg-hr when expressed relative to body weight, and 8.1 and 8.2 kcal/kg(LBW)-min when expressed relative to lean body weight. Thus, when body composition was considered, there were essentially no differences in the energy expenditure for males and females.

30. Zamparo P. Perini R. Orizio C, Sacher M & Ferretti G (1992): The energy cost of walking or running on sand. Eur.J.Appl.Physiol 65, 183-187.

Dipartimento di Scienze e Tecnologie Biomediche, Cattedra di Fisiologia, Udine, Italy. Oxygen uptake VO2 at steady state, heart rate and perceived exertion were determined on nine subjects (six men and three women) while walking (3-7 km.h-1) or running (7-14 km.h-1) on sand or on a firm surface. The women performed the walking tests only. The energy cost of locomotion per unit of distance (C) was then calculated from the ratio of VO2 to speed and expressed in J.kg1.m-1 assuming an energy equivalent of 20.9 J.ml 02-1. At the highest speeds C was adjusted for the measured lactate contribution (which ranged from approximately 2% to approximately 11% of the total). It was found that, when walking on sand, C increased linearly with speed from 3.1 J.kg-1.m-1 at 3 km.h-1 to 5.5 J.kg-1.m-1 at 7 km.h-1, whereas on a firm surface C attained a minimum of 2.3 J.kg-1.m-1 at 4.5 km.h-1 being greater at lower or higher speeds. On average, when walking at speeds greater than 3 km.h-1, C was about 1.8 times greater on sand than on compact terrain. When running on sand C was approximately independent of the speed, amounting to 5.3 J.kg-1.m-1, i.e. about 1.2 times greater than on compact terrain. These findings could be attributed to a reduced recovery of potential and kinetic energy at each stride when walking on sand (approximately 45% to be compared to approximately 65% on a firm surface) and to a reduced recovery of elastic energy when running on sand.