The motivational implications of characteristics of exercise bouts

The purpose of this research was to examine the psychological adaptations to two different exercise prescriptions. The dependent variables were three types of self-efficacy: task (for elemental aspects of the behavior); coping (for exercising under challenging circumstances); and scheduling (for arranging one's time commitments to exercise regularly). Participants were randomly assigned to one of two 12-week exercise prescriptions: a higher-intensity, shorter-duration condition (about 70 percent VO_2max, n = 21) and a lower-intensity, longer-duration condition (about 50 percent VO_2max, n = 23). The two conditions were equated for total work output (by manipulation of duration) in megajoules. The two exercise conditions produced similar aerobic fitness gains. Thus, the results regarding self-efficacy are not confounded by differential physical effects of the exercise prescriptions. Both groups were found to increase in task self-efficacy. The higher-intensity, shorter-duration group, however, showed an overall advantage in terms of coping (F[1,41] = 10.48, p < .002), and a group by time interaction was found for scheduling self-efficacy (F[2,39] = 3.81, p < .03) in favor of the higher-intensity, shorter-duration group. The motivational implications of the exercise prescriptions are discussed in terms of self-efficacy theory. It is concluded that it is important to consider not only the physical fitness implications of exercise prescription, but also the motivational implications. It is suggested that characteristics of the exercise bouts may influence motivation for subsequent physical activity involvement.