Thermal-Work Strain and Energy Expenditure during Marine Rifle Squad Operations in Afghanistan (August 2013).

摘要

Marines in-theater must often accomplish demanding mission goals in extreme environments. The collection of physiological and metabolic data provides a means to characterize, and potentially mitigate, thermal-work strain. Heart rate (HR), core body temperature (Tcore), skin temperature (Tskin), activity counts, and average total daily energy expenditures (TDEE) were collected from 19 USMC test volunteers in the 2nd Battalion 2nd Marines (2/2), Fox Company during regular patrols as well as non-mission activities while stationed in Afghanistan. All mission periods occurred during white/green or yellow Wet Bulb Globe Temperature (WBGT) flag conditions. Test volunteers (n = 13) experienced low levels of thermal-work strain during missions as indicated by mean physiological strain index (PSI) values between 2.7 and 3.6 PSI units with a maximum of 4.6. The combination of combat load and mission demands resulted in a mean TDEE of 13.20 1.41 MJ/day (3150 630 kcal/day, mean standard deviation, n = 17) as determined by doubly labeled water (DLW) over four days. Metabolic rates for mission activities were back calculated using Tcore and environmental data as inputs for the SCENARIO thermo regulatory model Mean modeled TDEE values were 13 18 criterion DLW method.