Predicting metabolic cost of running with and without backpack loads

SummaryIn the past, a mathematical equation to predict the metabolic cost of standing or walking (Mw) was developed. However, this equation was limited to speeds <2.2 m · s−1 and overestimated the metabolic cost of walking or running at higher speeds. The purpose of this study was, therefore, to develop a mathematical model for the metabolic cost of running (Mr), in order to be able to predict the metabolic cost under a wide range of speeds, external loads and grades. Twelve male subjects were tested on a level treadmill under different combinations of speed and external load. Speed varied between 2.2 to 3.2 m · s−1 using 0.2 m · s−1 intervals and external loads between 0–30 kg with 10 kg intervals. Four of the subjects were also tested at 2 and 4% incline while speed and load remained constant (2.4 m · s−1, 20 kg). The model developed is based on Mw and is proportionately linear with external load (L) carried as follows: $$M_r = M_w - 0.5(1 - 0.01L)(M_w - 15L - 850), (watt)$$ The correlation coefficient between predicted and observed values was 0.99 (P<0.01) with SER of 7.7%. The accuracy of the model was validated by its ability to predict the metabolic cost of running under different conditions extracted from the literature. A highly significant correlation (r=0.95,P<0.02, SER=6.5%) was found between our predicted and the reported values. In conclusion, the new equation permits accurate calculation of energy cost of running under a large range of speeds, external loads and inclines.

[1]  M Ogasawara,et al.  Energy expenditure in walking and running , 1934, The Journal of physiology.

[2]  A HENSCHEL,et al.  Maximal oxygen intake as an objective measure of cardio-respiratory performance. , 1955, Journal of applied physiology.

[3]  R. Margaria,et al.  Energy cost of running. , 1963, Journal of applied physiology.

[4]  B. Saltin,et al.  Muscle tissue lactate after maximal exercise in man. , 1968, Acta physiologica Scandinavica.

[5]  A nomogram to calculate the oxygen-cost of running at slow speeds. , 1969 .

[6]  A nomogram to calculate the oxygen-cost of running at slow speeds. , 1969, The Journal of sports medicine and physical fitness.

[7]  R G Soule,et al.  Energy cost of loads carried on the head, hands, or feet. , 1969, Journal of applied physiology.

[8]  L. Pugh Oxygen intake in track and treadmill running with observations on the effect of air resistance , 1970, The Journal of physiology.

[9]  E Kamon,et al.  The Physiological Cost of Carrying Loads in Temperate and Hot Environments , 1971, Human factors.

[10]  R. F. Goldman,et al.  Predicting metabolic energy cost. , 1971, Journal of applied physiology.

[11]  R. F. Goldman,et al.  Predicting rectal temperature response to work, environment, and clothing. , 1972, Journal of applied physiology.

[12]  R F Goldman,et al.  Predicting heart rate response to work, environment, and clothing. , 1973, Journal of applied physiology.

[13]  C. H. Wyndham,et al.  An equation for prediction of energy expenditure of walking and running. , 1973, Journal of applied physiology.

[14]  H. B. Falls,et al.  Energy cost of running and walking in young women. , 1976, Medicine and science in sports.

[15]  R. F. Goldman,et al.  Predicting energy expenditure with loads while standing or walking very slowly. , 1977, Journal of applied physiology: respiratory, environmental and exercise physiology.

[16]  W L Daniels,et al.  The energy cost and heart-rate response of trained and untrained subjects walking and running in shoes and boots. , 1984, Ergonomics.

[17]  S J Legg,et al.  Comparison of five modes of carrying a load close to the trunk. , 1985, Ergonomics.

[18]  K Francis,et al.  Changes in oxygen consumption associated with treadmill walking and running with light hand-carried weights. , 1986, Ergonomics.

[19]  W L Daniels,et al.  The energy cost of women walking and running in shoes and boots. , 1986, Ergonomics.

[20]  K B Pandolf,et al.  Prediction modeling of physiological responses and human performance in the heat. , 1986, Computers in biology and medicine.

[21]  S. Legg,et al.  Energy cost of backpacking in heavy boots. , 1986, Ergonomics.

[22]  R. F. Goldman,et al.  Predicting sweat loss response to exercise, environment and clothing , 2004, European Journal of Applied Physiology and Occupational Physiology.

[23]  Thomas G. Allison,et al.  Differentiated perceptions of exertion and energy cost of young women while carrying loads , 1982, European Journal of Applied Physiology and Occupational Physiology.

[24]  Y. Epstein,et al.  The energy cost of walking and running with and without a backpack load , 2004, European Journal of Applied Physiology and Occupational Physiology.