The coronary-prone behavior pattern and the suppression of fatigue on a treadmill test.

A study was conducted to test the hypothesis that Type A (coronary-prone) individuals would show greater suppression of subjective fatigue than Type B (non-coronary-prone) individuals in order to persist at a tiring but challenging task. Type A and Type B college students completed a Balke treadmill test (at a walking pace) while rating their fatigue at 2-minute intervals. Each subject also completed another treadmill test (at a running pace) that was designed to assess maximum aerobic capacity. Subjects' aerobic capacities and their aerobic performance levels attained on the Balke test were determined by analysis of expired air. Each subject's walking performance was scored as a proportion of his maximum aerobic capacity. Analysis of the resulting percentage values indicated greater effort among A's than B's. Moreover, the subjective fatigue ratings of A's were lower than those of B's. The results were discussed in terms of fatigue suppression as an instrumental response for attaining mastery over the environment. consideration was also given to the role of fatigue in the onset of coronary heart disease.