Metabolic Cost of Soldiers During Load Carriage at Self-selected Walking Speed in Different Gradient
Background: The ability to carry heavy loads over long distances for prolonged duration is a core functional competency for military personnel, particularly the infantry soldiers. They must not only be capable of performing arduous physical tasks, but must have the physical reserve to remain combat fit on completion of that particular task. The great interest of military researchers is to establish how well soldiers can perform their prime functions during and after load carrying.
Aims and Objectives: The present study was undertaken to assess the effect of different positive gradients on metabolic cost of soldiers during carrying of military loads at self selected walking speed.
Materials and Methods: Ten physically fit male infantry soldiers of Indian Army were volunteered for the study. Each volunteer completed twelve treadmill walking trials at their self-selected comfortable walking speed while carrying no external load, 10.7 kg and 21.4 kg loads for 10 min duration over four different gradients on treadmill. During walking trials heart rate (HR), oxygen consumption (VO2) and energy expenditure (EE) were determined by the process of breath-by-breath gas analysis using K4b² system (K4b², Cosmed S.r.l, Italy).
Result: The present study demonstrated that HR, VO2, EE and relative workload (%V.O2max) were raised with increasing gradients (5%, 10% and 15%) in comparison to level walking (0%) condition. Conclusion: Present study suggested that soldiers could carry 21.4 kg load upto15 % gradient at their self selected comfortable walking speed.