Energy cost of physical task performance in men and women wearing chemical protective clothing.
BACKGROUND: Chemical protective clothing (CPC) is required to perform certain occupations and is known to inhibit physical performance. Few data are available that quantify the physiological response of men and women during task performance while wearing CPC. HYPOTHESIS: The mobility of a task will have a significant effect on the change in energy cost. The energy cost of wearing CPC will be greater in women than men during physical task performance. METHODS: Energy cost (VO2) and the psychophysical scales, rating of perceived exertion (RPE) and respiratory distress (RD), were measured in 32 men and 26 women during the performance of 31 physical tasks. Tasks were categorized by mobility: stationary, intermittent or continuous. Between 6-12 men and 5-13 women conducted each task wearing 2 clothing conditions: battle-dress uniform (BDU, wt = 3.7 kg) and (CPC, wt = 9.3 kg). RESULTS: VO2 L x min(-1), was higher in CPC compared with BDU for the continuous task category for both genders. However, when VO2 (ml x kg(-1) clothed wt x min(-1)) was normalized for clothing weight, there remained a significant clothing effect for the continuous category, but there were no gender differences. VO2, expressed as a % VO2max, was significantly increased for BDU compared with CPC for the continuous task category only. This difference was significantly greater for women than men. Women exercised at a higher % VO2max and reported a higher RPE than men for all categories in both BDU and CPC. Both genders reported higher RD wearing CPC for the continuous task category only. CONCLUSIONS: There is an increase in energy cost wearing CPC during continuous tasks which can be attributed to both the clothing weight and the hobbling effect. Wearing CPC is more physiologically and psychologically demanding for women than men, especially when performing tasks of a continuous nature.