The Physiological Determinants of Load Bearing Performance at Different March Distances

Abstract : The purpose of this study was to further our knowledge of the physiological determinants of load bearing performance over distances from 2 to 12 km. Twenty eight soldiers, experienced in load bearing, were initially assessed for: aerobic power (VO2max), leg strength and muscular endurance, maximal lift capacity, maximal heart rate (HRmax), body composition, body anthropometry, and submaximal treadmill response to load bearing. Following a week of fitness assessment, each soldier performed four, best effort, load bearing trials at distances of 2, 4, 8 and 12 km. All trials were scheduled in random order on four successive weeks. The total load carried (pack, weapon, and clothing) was 46.12 kg. Mean performance times for each distance were 16.0, 35. 1, 77.2 and 125.0 minutes, respectively. Mean exercise intensity (% HRmax) as measured by HR telemetry for each trial was 74, 71, 69 and 63% respectively. Keywords: Loaded marching physical performance, Muscle strength, Aerobic fitness, Human factor engineering. (jes)