Effort of Dynamic Exercise: Influence of Load, Duration, and Task

The investigation examined the perceived effort of cycling and cranking with one and two limbs. Each task was performed at govern] loads for durations that ranged from 15 to 240 s. Magnitude estimates of effort increased as a nagatively accelerated power function of duration (exponent < 1.0) and a positively accelerated function of load (exponent > 1.0). The exponent of the functions for effort vs load was slightly groater than 1.4 and did not. vary systematically from one tusk to another. Effort of cycling was less than that of cranking, particularly at high loads, and grew more slowly over time. Similarly, effort of two-limb exercise was lower than that of one-liḿb exercise and grew more slowly over time. Local sensations from the working limbs accounted for most of the feelings of effort in all tusks. Central sensations from the cere of the body made only a relatively small contribution to overall effort. Contours of equal effort for various load-duration combinations resembled the endurance function that relates maximum duration of work to the load.