Effect of long-distance load marching on physiological responses at desert environment

AIM: The present study was undertaken to examine the effect of long-distance load marching on the physiological responses, walking efficiency, and mobility of soldiers at sandy desert environment. METHODS: A total of nine physically fit soldiers (age, 30.00 [SE 0.9] years; height, 175.56 [SE 1.18] cm; and weight, 77.83 [SE 1.37] kg) volunteered for long-distance (6 km) load marching by self-selected speed when carrying 22 kg (28.27% of body weight [BW]) load and no load (NL). Heart rate (HR), respiratory frequency (RF), and core body temperature (CBT) were recorded. Relative workload (RWL) and Physiological Cost Index (PCI) were calculated to assess the work intensity and mobility. RESULTS: It was observed that HR (P = 0.01), RWL (P = 0.01), and PCI (P = 0.01) were significantly increased by 23.79, 39.71, and 77.73%, respectively, and mobility was significantly reduced (P = 0.01) by 18.56% during marching with 22 kg load as compared to NL. CONCLUSION: It may be that marching without external load at speed of 4.85 ± 0.54 km/h should not be continued for more than 2 h, whereas marching with load of 28.27% of BW at speed of 3.95 ± 0.55 km/h should be restricted to maximum 30 min. This combination of load, speed, and duration provides information about soldiers' routine load carriage tasks, which may help in optimizing the load carriage task to reduce the chances of cumulative carriage-related injuries and, therefore, may contribute to improved soldiers' operational readiness and mobility.