5. Elderly

1. Calloway DH & Zanni E (1980): Energy requirements and energy expenditure of elderly men. Am.J.Clin.Nutr. 33, 2088-2092.

Basal metabolic rates (BMR) and energy cost of a few activities were measured in healthy men aged 63 to 77 years who were participants in a study of protein requirements (previously reported). The men were confined to a metabolic unit for 47 days and received a defined formula diet. Their body weights were 8 to 19 kg higher than that of younger men of the same heights and their whole body potassium content was 12% less than that of younger men (average 28 years of age) studied in the same unit. BMR of the older men was 1622 +/- 189 kcal/day, a figure 13% below the per diem rate of younger men but the same per unit of body potassium. Energy cost of sedentary activities was related to BMR. Expenditure while Iying at rest was 1.22 X BMR and while sitting quietly, 1.30 X BMR; these values are the same as in younger men. Walking level at about 2.5 mph cost 4.51 +/-0.34 kcal/min (about 4 X BMR) and cycling at a comfortable load (300 to 400 kpm) only slightly more. Energy intake required to maintain body weight of these men, who were sedentary except for 30 min of cycling daily, was 2554 +/- 222 kcal/day, or about 1.6 X BMR. Minimum maintenance energy requirement (i.e., ambulatory but inactive) of healthy older men appears to be 1.5 X BMR, the same as in other age groups.

2. Didier JP, Mourey F. Brondel L, Marcer I, Milan C, Casillas JM, Verges B & Winsland JK (1993): The energetic cost of some daily activities: a comparison in a young and old population. Age Ageing, 22, 90-96.

Groupe d'Etude et de Recherche sur le Handicap, C.H.R.U. de Dijon, France. The energetic costs of some daily activities were compared in two groups, 10 young people (24.3 +/- 2.8 years) and 10 old people (74.4 +/- 2.2 years): rising and sitting back down on a seat, getting up from and Iying down on a bed and getting up from the floor. The oxygen consumption and the time necessary for the activities were measured. The results showed a noteworthy economical energetic procedure when rising and sitting back down on a seat among the older group. The values of the energy expenditure were respectively 3.9 +/- 1.3 car/kg in the older group and 5.8 +/- 1.6 in the younger one with a standard seat (45 cm) and 2.7 +/- 1.2 vs 5.2 +/- 1.5 with a raised seat (60 cm). The activities did not vary significantly in time in the two age groups. This procedure could be understood as an adaptation of the energy expenditure to the reduced aerobic capacity with ageing. Conversely, getting up from and Iying down on the floor or a standard hospital bed involved the same energy expenditure in the older and younger group, but performing these activities took significantly longer for the older people (+60% for getting up from the floor, +33% from the bed). As these activities revealed no economical energetic procedure in the older group, they appeared responsible for a strong factor of dependence. The importance of a learning process particularly for the most usual movements in everyday life is discussed.

3. Evans BW, Potteiger JA, Bray MC & Tuttle JL (1994): Metabolic and hemodynamic responses to walking with hand weights in older individuals. Med.Sci.Sport Exerc. 26, 10471052.

Department of Physical Education, Indiana State University, Terre Haute, USA. The purpose of this study was to examine metabolic and hemodynamic responses of older adults (age = 66.2 +/5.6 yr) to walking with hand-held weights (HHW). Nineteen volunteers participated in eight randomly assigned, 10-min, submaximal, self-selected constant speed (CSP) or constant heart rate (CHR) exercise bouts using the following HHW conditions: no weight, W0; 0.45 kg, W1; 1.36 kg, W3; 2.27 kg, W5. Oxygen uptake VO2 was recorded every 30 s, heart rate (HR) each minute, and blood pressure (BP) every 2 min. Mean values for the last 5 min of exercise were analyzed using repeated measures ANOVA. Contrast comparison tests were used to determine differences among means. During CS, significant differences between means (P < or = 0.05) existed for: VO2 (W0, W1 < W3, W5); HR, SBP, DBP, SBPmax, DBPmax (W0 < W1, W3, W5); HR, rate pressure product (RPP), DBPmax (W1 < W5); SBP, DBP, SBPmax, RPP (W3 < W5). During CHR, significant differences (P < or = 0.05) between means existed for: SBP, DBP, RPP (W0, W1, W3 c W5); DBP (W0 < W3; W1, W3 < W5). These results indicate that the use of HHW significantly increases metabolic responses at W3 and W5 during CS exercise in older adults, while hemodynamic responses increase significantly across HHW for both CS and CHR. Due to the increases in hemodynamic responses, the use of HHW may be contraindicated for older individuals with suspected or diagnosed cardiovascular disease.

4. Treuth MS, Hunter GR, Weinsier RL & Kell SH (1995): Energy expenditure and substrate utilization in older women after strength training: 24-h calorimeter results. .J.Appl.Physiol 78, 2140-2146.

Department of Nutrition Science, University of Alabama at Birmingham, 35294-3360, USA. The purpose of this study was to examine the effects of strength training (ST) in healthy older women on 24-h energy expenditure (EE) and its components and on 24-h substrate utilization. Thirteen women (age 67 +/- 1 yr) exercised three times per week for 16 wk in a total body ST program. EE components and substrate utilization were determined for 24 h in an indirect room calorimeter before and after training. The ST invoked a 47% increase in upper body and a 66% increase in lower body strength (P < 0.001). Body weight, percent body fat, and fat-free mass did not change significantly; however, midthigh muscle area increased (55.2 +/- 3.1 vs. 60.4 +/2.3 cm2; P < 0.05). There is a significant increase in resting EE (5,017 +/- 218 vs. 5,473 +/- 213 kJ/day; P < 0.05) but no significant changes in sleeping EE (4,929 +/- 180 vs. 5,067 +/- 251 kJ/day), diet-induced thermogenesis (359 +/- 25 vs. 393 +/- 33 kJ/day), activity EE (682 +/- 84 vs. 381 +/117 kJ/day), or 24-h EE (6, 054 +/- 188 vs. 6,247 +/- 243 kJ/day). The increase in resting EE is not significant after the increase in muscle area is taken into account. The 24-h nonprotein respiratory quotient decreased (0.90 +/- 0.01 vs. 0.82 +/- 0.01; P < 0.001), revealing a significant increase in 24-h fat oxidation (42 +/- 6 vs. 81 +/- 7 g/day) and a decrease in carbohydrate oxidation (180 +/- 14 vs. 113 +/- 10 g/day; both P < 0.001). In conclusion, ST increases resting EE and fat oxidation, which may have important implications in improving the metabolic profile of older adults. The increase in resting EE may be partly explained by increased muscle mass.

5. Visser M, van der Horst A, de Groot LC, Deurenberg P & van Staveren WA (1995): Energy cost of physical activities in healthy elderly women. Metabolism, 44, 1046-1051.

Department of Human Nutrition, Wageningen Agricultural University, The Netherlands. In recent studies, daily physical activity ratios (PARs) greater than the Food and Agriculture Organization/World Health Organization/United Nations University (FAO/WHO/UNU) reference value of 1.5 have been reported for elderly men and women. The purpose of this study was to investigate whether a high PAR in elderly subjects can be explained by a higher energy cost of physical activities (EEact). To this end, 12 elderly women aged 69 to 82 years, completed physical activity diaries during a 2-day stay in a respiration chamber. From these diaries, total daily energy expenditure (TEE) in the calorimeter was estimated (TEEfac) using FAO/WHO/UNU PARs for physical activities and measured resting metabolic rate (RMR). TEEfac was 7.0 +/- 0.9 MJ/d (PAR, 1.35 +/- 0.06). TEE was also measured in the chamber (TEEcal) and was 8.3 +/- 1.3 MJ/d (PAR, 1.60 +/- 0.16). TEEfac was 14.8% +/- 8.1% lower than TEEcal. To investigate whether the underestimation of TEEcal was due to a higher EEact in the elderly women as compared with the FAO/WHO/UNU references, EEact of six specific activities ranging from sitting at rest to walking on a treadmill at self-chosen speed was measured with a ventilated-hood system. Individually measured PARs of the six activities were similar to FAO/WHO/UNU reference PARs. This study suggests that in elderly women a high TEEcal is not explained by EEact during nonstandardized physical activities performed at self-chosen speeds. Whether these results car. be extrapolated to the free-living environment needs to be investigated further.

6. Voorrips LE, van Acker TMJ, Deurenberg P & van Staveren WA (1993): Energy expenditure at rest and during standardized activities: a comparison between elderly and middle-aged women. Am. J. Clin. Nutr. 58,15-20.

Department of Human Nutrition, Wageningen Agricultural University, The Netherlands. To estimate energy expenditure (EE) in elderly subjects, more age-specific data are required on energy costs of standardized activities. EE was assessed by using indirect calorimetry in 28 women aged 72 +/- 4 y (mean +/- SD) and in 29 middle-aged women (42 +/- 1 y) at rest (resting metabolic rate; RMR) and during sitting, sitting with standardized arm activity, and walking on a treadmill at 3 km/in. RMR and EE during sitting, and sitting with standardized arm activity did not differ significantly between the groups, although EE expressed as a ratio of arm activity to RMR (physical activity ratio, PAR) tended to be higher in the elderly subjects. Walking EE was significantly higher in the elderly women (16.4 +/-4.0 kJ/min) than in the middle-aged women (12.7 +/- 2.3 kJ/min), also when expressed as PAR. It is suggested that elderly women walk less efficiently. Because PARs are frequently used to estimate daily EE, it is important to note that additional age-specific data might be required.

7. Waters RL, Hislop HJ, Perry J. Thomas L & Campbell J (1983): Comparative cost of walking in young and old adults. J.Orthop.Res. 1, 73-76.

Normative data that summarize the energy requirements and gait characteristics of level outdoor walking were determined in 111 normal subjects between the ages of 20 and 80 years. Subjects were divided into two age groups: young adults (20-59 years) and senior subjects (6080 years). The mean rate of oxygen consumption for young adults and senior subjects did not significantly differ, averaging 11.9 ml/kg-min for both groups. The data on heart rate paralleled the findings on oxygen consumption, averaging 100 and 103 beats/min, respectively. The net oxygen cost per meter walked for senior subjects, 0.16 ml/kg-m, was significantly greater (p < 0.0005) than the value for young adults, 0.15 ml/kg-m, due to a decline in the average walking speed. The average gait velocity for senior subjects, 73 m/min, was statistically significantly less (p < 0.0005) than the values for the younger adults, 80 m/mint

8. Waters RL, Lunsford BR, Perry J & Byrd R (1988): Energy-speed relationship of walking: standard tables. J.Orthop.Res. 6, 215-222.

Department of Surgery, Rancho Los Amigos Medical Center, Downey 90242. The energy expenditure of level walking was measured in 260 normal male and female subjects walking around a 60.5m-circular outdoor track. Subjects were divided into four age groups (children, 612 years; teens; young adults, 20-59 years; and senior adults, 60-80 years). Oxygen consumption was measured with a modified Douglas Bag technique during the fourth and fifth minutes of each trial. Standard tables according to age and sex were derived for the average energy expenditure (rate of oxygen uptake, energy cost per meter, and heart rate) and for the gait characteristics (speed, cadence, stride length) at the subjects' customary slow, normal, and fast walking speeds. Statistical analysis was performed to determine the energy-speed relationship for the different age groups to derive normative tables for the rate of oxygen uptake throughout the range of customary walking velocities.