The Pandolf equation under-predicts the metabolic rate of contemporary military load carriage

Abstract

ObjectivesThis investigation assessed the accuracy of error of the Pandolf load carriage energy expenditure equation when simulating contemporary military conditions (load distribution, external load and walking speed). DesignWithin-participant design. MethodsSixteen male participants completed 10 trials comprised of five walking speeds (2.5, 3.5, 4.5, 5.5 and 6.5km·h−1) and two external loads (22.7 and 38.4kg). ResultsThe Pandolf equation demonstrated poor predictive precision, with a mean bias of 124.9W and −48.7 to 298.5W 95% limits of agreement. Furthermore, the Pandolf equation systematically under-predicted metabolic rate (p<0.05) across the 10 speed-load combinations. Predicted metabolic rate error ranged from 12–33% across all conditions with the ‘moderate’ walking speeds (i.e. 4.5–5.5km·h−1) yielding less prediction error (12–17%) when compared to the slower and faster walking speeds (21–33%). ConclusionsFactors such as mechanical efficiency and load distribution contribute to the impaired predictive accuracy. The authors suggest the Pandolf equation should be applied to military load carriage with caution.