Abstract
Each subject performed eight works by bicycle ergometer or treadmill. From data on oxygen uptake and heart rate during work and recovery, total oxygen cost and total cardiac cost above resting level were calculated on four male students. Total cost correlated closely with work performed in oxygen cost and cardiac cost. The relation of total oxygen cost to total cardiac cost was different between bicycle ergometer work and treadmill walk. Both in oxygen cost and in cardiac cost, linear relation was found between recovery cost above resting level and total cost irrespective of work type.
When it is difficult to record physiological reactions during work, recovery cost is sufficient to evaluate physiological cost of the work. In recovery cost above resting level, there are two problems, measurement of resting value and prolongation of measuring time during recovery period. The first three-minute recovery cost above zero correlated linearly with total cost both in oxygen cost and in cardiac cost irrespective of work type. The evaluation of physiological cost of work by the threeminute recovery cost above zero is considered to be practically useful.
