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

Authors

  • Adam W Potter U.S. Army Research Institute of Environmental Medicine (USARIEM)
  • David P Looney
  • Laurie A Blanchard
  • Alexander P Welles
  • William R Santee

DOI:

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

Keywords:

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

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.

Author Biography

  • Adam W Potter, U.S. Army Research Institute of Environmental Medicine (USARIEM)
    Adam Potter is a Research Physiologist and the Deputy Chief of the Biophysics and Biomedical Modeling Division (BBMD) at the U.S. Army Research Institute of Environmental Medicine (USARIEM). Prior to his work in research, he served on active duty in the U.S. Marine Corps, participating in real-world operations in Kosovo, Iraq, and Liberia. His military awards include: the Navy and Marine Corps Achievement Medal, Combat Action Ribbon, Marine Corps Good Conduct Medal, National Defense Service Medal, the Iraq Campaign Medal (w/Bronze Star), the Global War on Terrorism Service Medal, the Humanitarian Service Medal, and the Sea Service Deployment Ribbon (w/Bronze Star). Mr. Potter holds a Bachelor of Arts (BA) in Psychology from Cambridge College, a Masters of Business Administration (MBA) and a Master of Science (MS) in Sports and Health Sciences from American Military University, and is currently working towards a PhD in Biomedical and Health Informatics with a concentration in Nanomedicine from Rutgers University. As a Principle Investigator at USARIEM he leads non-human and human research protocols in the areas of thermal manikins, thermoregulatory modeling, metabolic cost studies, and real-time monitoring of physiological responses to various military operational activities. His research portfolio spans across the applied sciences, e.g., manikin testing, to the cutting-edge of product development, e.g., computer-based decision aids and wearable sensors.

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Published

2017-07-07

Issue

Vol. 5 No. 1 (2017): Journal of Sport and Human Performance

Section

Original Research Articles

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How to Cite

Accuracy of predictive equations for metabolic cost of locomotion while carrying external load. (2017). Journal of Sport and Human Performance, 5(1). https://doi.org/10.12922/jshp.v5i1.124