Cardiac responses under diverse combinations of marching speed and backpack load

Abstract

Thirty seasoned foot-soldiers were exposed to a total of 16 combinations of marching speed and backpack load, each soldier experiencing 8 of the combinations between 3.5km.h-1 with a 20kg load and 6.5km.h-1 with a 65kg load. Detailed physiological analyses were conducted, of which the heart rate responses are reported here. Steady state was achieved with all combinations under 5.5km.h-1 speed and 35kg load. Excessively elevated heart rates were elicited by all loads over 20kg at 6.5km.h-1 marching speed; by loads over 35kg at 5.5km.h-1 marching speed and by the 65kg load even at 4.5km.h-1 marching speed.