Metabolic, cardiovascular and spinal strain of a representative fuel replenishment task

The metabolic, cardiovascular and spinal strain of a representative fuel replenishment task for a tank crew were assessed using nine military subjects wearing coveralls in a comfortable ambient climate. The task involved lifting 5 gal jerry cans (weighing 23·4 kg) from the ground to a height representing a tank deck (1·676 m) at a rate of two lifts per minute for 15 min. Oxygen uptake ([Vdot]O2), minute ventilation ([Vdot]E), heart rate (HR) and intra-abdominal pressure (IAP) were monitored continuously. After 15 min of lifting the mean [Vdot]O2 was 0·821 min−1 (S.D. 0·18). This was 27% of the predicted [Vdot]O2 max. The mean [Vdot]E was 21·81 min−1 (S.D.4·1) and the HR was 111·3 beats min−1 (S.D. 17·8). The mean peak IAP was 105·6 mmHg, with 56% of the peak IAPs exceeding 90 Hg. The mean intrasubject coefficient of variation was 10·7% (range 7·2–24·2). In a separate series of 20 consecutive bimanual straight arm vertical lifts of 10 kg at 15 s intervals, the mean intrasubject COV% was 7·2% (range 3·2–11·...