Accuracy of predictive equations for metabolic cost of locomotion while carrying external load

Adam W Potter, David P Looney, Laurie A Blanchard, Alexander P Welles, William R Santee

Abstract


Introduction: Energy cost estimation of dismounted military movements is of significant importance for a number of reasons, including optimal performance planning and to ensure individual safety.  Predicting energy costs during military road marches, i.e., locomotion, requires insights into key factors such as: body mass, clothing, any additional load carried, walking velocity, surface grade, and other terrain features (e.g., pavement, gravel, snow).  Methods: Physiological measures and measures of oxygen uptake (VO2) were collected from nine individual Soldiers (age, 22 ± 4 (SD) y; wt, 76.44 ± 10.67  kg; ht, 175.00 ± 10.14 cm; body fat, 23.4 ± 5.8%; VO2max, 49.22 ± 3.33 ml•kg-1•min-1), during treadmill exercise in an environmental chamber.  Volunteers walked at two different work intensities, approximately 350 and 540 W: under warm-humid (air temperature (Ta) 25°C, 50% relative humidity (RH)), hot-humid (35°C, 70% RH), and hot-dry (40°C, 20% RH) environmental conditions.  Observed VO2 values, in W, were compared to predicted total energy costs from four predictive equations using the root mean square error (RMSE), mean absolute error (MAE), and correlation coefficient (R2) values.  Results: Analyses showed predictions were in close agreement with measured values, with RMSE ranging from 19.56 to 38.16 W, MAE from 15.71 to 28.9 W, and R2 from 0.86 to 0.96.  Conclusion: The results indicate that for the specified test conditions, metabolic estimation equations can be used to accurately predict energy expenditure of walking locomotion.  These equations accurately predict energy costs when individual differences exist in external load, walking velocity, moderate differences in grade increased surface grade, and different levels of thermal stress.


Keywords


energy expenditure, exercise, predictive equations, modeling, human locomotion

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References


FM 21-18 (1990). Foot marches, Department of the Army. Washington, D.C.

Knapik J, Reynolds K. Chapter 11. Load carriage in military operations: a review of historical, physiological, biomechanical and medical aspects. In: : Friedl K.E. and W.R. Santee (eds), Military quantitative physiology: problems and concepts in military operational medicine. Office of the Surgeon General and the Borden Institute, Ft. Detrick, MD. 2012:303-37.

Tharion WJ, Lieberman HR, Montain SJ, Young AJ, Baker-Fulco CJ, DeLany JP, Hoyt RW. Energy requirements of military personnel. Appetite. 2005; 44(1):47-65.

American College of Sports Medicine. ACSM's guidelines for exercise testing and prescription (6th ed.). Baltimore, MD: Lippincott Williams & Wilkins; 2002.

Givoni B, Goldman RF. Predicting metabolic energy cost. Journal of Applied Physiology. 1971;30(3):429-33.

Pandolf KB, Givoni B, Goldman RF. Predicting energy expenditure with loads while standing or walking very slowly. Journal of Applied Physiology. 1977; 43(4):577-81.

Santee WR, Allison WF, Blanchard LA, Small MG. A proposed model for load carriage on sloped terrain. Aviation, Space, and Environmental Medicine, 2001; 72(6), 562-566.

Santee WR, Xu X, Yokota M, Buller MJ, Karis AJ, Mullen SP, Gonzalez JA, Blanchard LA, Welles AP, Cadarette BS, Potter AW, and Hoyt RW. Core temperature and surface heat flux during exercise in heat while wearing body armor. US Army Research Institute of Environmental Medicine, Natick, MA, 01760, USA, Technical Report, T16-1, 2015, ADA#622653, accessible at: www.dtic.mil/dtic/tr/fulltext/u2/a622653.pdf

Potter AW, Santee WR, Clements CM, Brooks KA, Hoyt RW. Comparative Analysis of Metabolic Cost Equations: A Review. Journal of Sport and Human Performance, 2013; 1(3).

Danielsson U, & Grambo S. Position och arbetsbelastning i fält. Direktmätning och beräkning från GPS-data. 2003.

Bach AJ, Costello JT, Borg DN, Stewart IB. The Pandolf load carriage equation is a poor predictor of metabolic rate while wearing explosive ordnance disposal protective clothing. Ergonomics, 2016; 1-9.

Dorman LE, Havenith G. The effects of protective clothing on energy consumption during different activities. European Journal of Applied Physiology, 2009; 105(3), 463–470.

Santee WR, Blanchard LA, Speckman KL, Gonzalez JA, Wallace RF. Load carriage model development and testing with field data. US Army Research Institute of Environmental Medicine, Natick, MA, 01760, USA, Technical Note, TN03-3, 2003

Richmond PW, Potter AW, Santee WR. Terrain factors for predicting walking and load carriage energy costs: Review and refinement. Journal of Sport and Human Performance, 2015; 3(3):1-26.




DOI: https://doi.org/10.12922/jshp.v5i1.124

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