Evaluation of physiological cost in dynamic muscular work by recovery cost

II. In different work loads and durations of work

Abstract

Four male students performed bicycle ergometer work at different work loads (0-900kgm/min) for different durations of work (4-15mm). From the data on oxygen uptake and heart rate during work and recovery, oxygen cost and cardiac cost per minute of the work above resting level were calculated. At the same work load, oxygen cost and cardiac cost per minute of work were almost same regardless of different durations of work. The regression of cost per minute against work load was linear in oxygen cost, and quadratic in cardiac cost.
If the duration of work is taken into account, the total oxygen or cardiac cost per minute can be estimated by the recovery cost above resting level on the basis of their linear relationship. In practical situations, the method by the 3-min recovery cost above zero is considered to be useful for the evaluation of oxygen cost as well as cardiac cost.