Thermal-Work Strain and Energy Expenditure during Marine Rifle Squad Operations in Afghanistan (August 2013)
Technical rept. 2013-2015
ARMY RESEARCH INST OF ENVIRONMENTAL MEDICINE NATICK MA BIOPHYSICS AND BIOMEDICAL MODELING DIV
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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 22, Fox Company during regular patrols as well as non-mission activities while stationed in Afghanistan. All mission periods occurred during whitegreen 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 MJday 3150 630 kcalday, 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.
- Anatomy and Physiology
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