Effects of MOPP Configurations and Two Drinking Systems on Fluid Balance and Performance

摘要

The impact of wearing MOPP on fluid balance, thermoregulation and performance was evaluated. Fifteen male soldiers walked for 6 consecutive 50/10 min. work/rest cycles on two non-consecutive days and iodinated water (30 C) was consumed ad-lib. On one day, soldiers wore the Battle Dress Uniform (BDU) and drank from canteens; on the second day, they wore MOPP IV and drank with either the current gravity feed system (CS) or a fluid hydraulic (FH) system. All BDU subjects completed the entire 300 min of exercise, and average water intake (0.25 L/hr) partially compensated for sweat losses (SR) of 0.37 L/hr that contributed to body weight (WT) losses of 0.24 kg/hr. During work bouts, CS drank significantly less than FH (0.28 vs 0.42 L/hr, respectively). While SR was similar in both groups (0.84 L/hr) and markedly increased relative to BDU, WT deficits were doubled those of BDU. Increased SR and inadequate rehydration produced increases in heart rate (49 bpm) and heat storage (33 kcal/m2) contributing to performance decrements in CS (210 min) and FH (231 min). Both CS and FH perceived more symptoms of hyperthermia and dehydration, and rated their final walk significantly more difficult than their first. The results demonstrate that physiological and perceptual decrements can occur when MOPP IV level is worn during low intensity work in a warm climate, that a FH system may improve drinking during work/exercise. Keywords: MOPP 4: Heat tolerance: Protective clothing: Water consumption: Stress physiology. (kr)