Metabolic Effects of Soldier Performance on a Simulated Graded Road March while Wearing Two Functionally Equivalent Military Ensembles

Abstract

The purpose of this study was to examine metabolic effects of soldier performance on a simulated road march, comparing two functionally equivalent military ensembles (FEMEs) with changing gradation of marching, and to create prediction equations addressing workload with different loads and treadmill grades. Fourteen male military subjects were tested while wearing two different FEMEs on a graded (0%, 5%, or 10%), 3.5 miles/h, road march for 30 minutes. Data collected included oxygen uptake (VO2), carbon dioxide output, ventilation, respiratory exchange ratio, and heart rate (HR). No significant differences were found between the two FEMEs in each graded condition. Combining ensemble data, significant differences occurred in all conditions, comparing all grades. A 10% graded road march (3.5 miles/h, approximately 27-kg load) represented 61% to 90% of maximal values. For treadmill grades of <10%, VO2 and HR were modeled as follows (adjusted R2 = 0.89 [VO2] and 0.82 [HR]): VO2 (mL/kg per minute) = 10 + [2 - grade (%)] + [0.2 - load (% of body mass)]; HR (beats per minute) = 90 + [6 . grade (%)] + [0.7 - load (% of body mass)]. Three factors, namely, elevation grade, equipment weight (load), and overall subject physical abilities, were significant for overall metabolic demand during a simulated graded road march and might affect field performance.