|Bibliography of Studies of the Energy Cost of Physical Activity in Humans (London School of Hygiene and Tropical Medicine, 1997, 162 p.)|
1. Anonymous (1967): Energy cost of simulated space activities. Nutr.Rev. 25, 301-304.
Simulation of space conditions indicates that human energy requirements are decreased by reduced G-force but increased by suit pressurization. Heat removal may be inadequate for extravehicular activities in present suits. This paper presents the findings from studies which have attempted to simulate various features of space activities, such as reduced gravitational forces and features related to life support systems.
2. Anonymous (1971): Ergonomics guide to assessment of metabolic and cardiac costs of physical work. Am.lnd.Hyg.Assoc.J. 32, 560-564.
This paper discusses the significance of and ways to determine the energy costs and heart rates associated with the performance of physical tasks. Such information may be of use in achieving adjustments between the physical capacities of workers and job demands. Some data from the literature on the energy cost of various occupational activities are presented [not original abstract]
3. Ainsworth BE, Haskell WL, Leon AS, Jacobs DR, Jr., Montoye HJ, Sallis JF & Paffenbarger RS, Jr. (1993): Compendium of physical activities: classification of energy costs of physical activitites. Med.Sci.Sport Exerc. 25, 71-80.
A coding scheme is presented for classifying physical activity by rate of energy expenditure, ie, by intensity. Energy cost was established by a review of published and unpublished data. This coding scheme employs 5 digits that classify activity by purpose (de, sports, occupation, self-care), the specific type of activity, and its intensity as the ratio of work metabolic rate to resting metabolic rate (METs). Energy expenditure in kilocalories or kilocalories per kilogram body weight can be estimated for all activitites, specific activitites, or activity types. General use of this coding scheme would enhance the comparability of results across studies using self report of physical activity.
4. Jette M, Sidney K & Blumchen G (1990): Metabolic equivalents (METS) in exercise testing, exercise prescription, and evaluation of functional capacity. Clin.Cardiol. 13, 555-565.
Department of Kinanthropology, School of Human Kinetics, University of Ottawa, Canada. One metabolic equivalent (MET) is defined as the amount of oxygen consumed while sitting at rest and is equal to 3.5 ml 02 per kg body weight x min. The MET concept represents a simple, practical, and easily understood procedure for expressing the energy cost of physical activities as a multiple of the resting metabolic rate. The energy cost of an activity can be determined by dividing the relative oxygen cost of the activity (ml O2/kg/min) x by 3.5. This article summarizes and presents energy expenditure values for numerous household and recreational activities in both METS and watts units. Also, the intensity levels (in METS) for selected exercise protocols are compared stage by stage. In spite of its limitations, the MET concept provides a convenient method to describe the functional capacity or exercise tolerance of an individual as determined from progressive exercise testing and to define a repertoire of physical activities in which a person may participate safely, without exceeding a prescribed intensity level.
5. Lane HW (1 992): Energy requirements for space flight. J.Nutr. 122, 13-18.
Biomedical Operations and Research Branch, NASA-Johnson Space Center, Houston, TX 77058. Both the United States and the Soviet Union perform human space research. This paper reviews data available on energy metabolism in the microgravity of space flight. The level of energy utilization in space seems to be similar to that on Earth, as does energy availability. However, despite adequate intake of energy and protein and in-flight exercise, lean body mass was catabolized, as indicated by negative nitrogen balance. Metabolic studies during simulated microgravity (bed rest) and true microgravity in flight have shown changes in blood glucose, fatty acids and insulin concentrations, suggesting that energy metabolism may be altered during space flight. Future research should focus on the interactions of lean body mass, diet and exercise in space, and their roles in energy metabolism during space flight.
6. McCarroll JE, Goldman RF & Denniston JC (1979): Food intake and energy expenditure in cold weather military training. Mil Med. 144, 606-610.
This paper examines the question of energy demands of military activities in a cold environment and the associated food requirements. The metabolic effects of cold on skin temperature are shivering and non-shivering thermogenesis. These effects are negligible for the well-clothed person since the temperature is not lowered. Acclimatization to cold is a complicated phenomenon which has only slight gains in comfort compared with the time required to achieve it. Energy expenditure (activity) is the primary determinant of food requirements. An energy expenditure prediction is presented for practical use when the following factors are known: load carried, velocity of movement, and the type of terrain. Estimates of energy expenditure for various military activities are presented, in order to allow the reader to make rough estimates of energy demands upon troops in varying terrains and using different means of mobility. Using these estimates, a scenario can be created and food requirements can be predicted.
7. Numajiri K & Shindo H (1970): Energy expenditure of industrial workers in Japan. J.Sci.Labour, 46, 383-388.
This paper discusses the use of RMR (relative metabolic rate) as an indicator of the intensity of muscular work. RMR is defined as the quotient of energy requirement of work by basal metabolism:
R = resting metabolism
W = work metabolism
BM = basal metabolism
RMR can be converted into energy expenditure: energy expenditure (kcals) = (RMR x 1.2) x BM
1.2 is the average ratio of resting metabolism to basal metabolism.
Some previously gathered data on the RMR of various occupational activities are presented and also the daily energy expenditure of some occupational groups.
8. Shephard RJ (1982): The daily work-load of the postal carrier. J.Hum.Ergol. 11, 157-164.
An analysis of physical demand shows that a male postal carrier may sustain an 8 hr energy expenditure of 21.8 kJ.min-1, with an average of 28.4 kJ.min-1 for 4-5 hr of walking the route, and a peak output of 40.6 kJ.min-1. Comparable figures for a female carrier are 17.7, 23.0 and 32.7 kJ.min-1. The work is close to the physiological limit for older individuals, but complaints are few due to (i) the conditioning effect of employment, (ii) selective elimination of inappropriate employees, (iii) relatively early retirement, and (iv) ability of older employees to bid for easier mail routes.
9. Shephard RJ (1987): Science and medicine of canoeing and kayaking. Sports Med. 4, 19-33. Canoeing and kayaking are upper-body sports that make varying demands on the body, depending on the type of contest and the distance covered. The shorter events (500 m) are primarily anaerobic (2 minutes of exercise), calling for powerful shoulder muscles with a high proportion of fast-twitch fibres. In contrast, 10,000 m events call for aerobic work to be performed by the arms. Such contestants need a high proportion of slow-twitch fibres, and an ability to develop close to 100% of their leg maximum oxygen intake when paddling. In slalom and whitewater contests, the value of physiological testing is somewhat limited, since performance is strongly influenced by experience and the ability to make precisely judged rapid paddling efforts under considerable emotional stress. Paddlers face dangers from their hostile cold water environment; causes of fatalities (drowning, cardiac arrest, ventricular fibrillation and hypothermia) are briefly reviewed. Medical problems include provision of adequate nutrition and a clean water supply, effects of repeated immersion (softening of the skin, blistering, paronychial infections, sinusitis, otitis), varicose veins (secondary to thoracic fixation) and hazards of exposure to fibreglass and polystyrene in the home workshop. Surgical problems include muscle sprains and mechanical injuries (haemotomas, lacerations, contusions, concussion, and fractures).
10. Torun B (1990): Energy cost of various physical activities in healthy children. In: Activity, energy expenditure and energy requirements of infants and children. Proceedings of an IDECG workshop held in Cambridge, Massachuseffs, USA, November 14-17, 1989, edited by B. Schurch, et al, pp. 139-183. IDECG, Switzerland.
Twenty-eight studies that measured the energy cost of several common activities of children were found through an extensive literature search and personal communications. The characteristics of the children, the method used to measure energy expenditure and the energy costs of the activities from each study are presented in summer tables. The children's basal metabolic rate (BMR) and the energy cost of activities per kg or as multiples of BMR (X BMR) were calculated to present the data uniformly. The activities were classified in ten categories. In most age groups there is no information about the energy cost of household work, agricultural chores, other common tasks, and many sports or games, especially for girls. Although the methodology varied between studies and the activities were not standardized, the data suggest that when energy costs are expressed as X BMR: (a) they are similar for boys and girls, (b) there are no age-related differences in sedentary activities, (c) the cost of walking and moving around increases from preschool years to mid-adolescence, and (d) energy costs from 15 years onwards are similar to those of adults. The use of energy costs of adults per kg of body weight to calculate energy costs of children leads to errors which increase with decreasing age. Suggestions are made to estimate the energy costs of children based on their known or calculated BMR and from similar activities of adults expressed as fractional multiples of BMR. Additional investigations are necessary to confirm whether there are differences related to racial, geographic and socioeconomic conditions.