The effect of prescribed and preferred intensity exercise on psychological affect and the influence of baseline measures of affect.

This study compared the effects of 20 minutes of treadmill exercise at a prescribed intensity exercise (65% VO(2)max) and a preferred intensity exercise on psychological affect and exercise enjoyment in aerobically fit individuals. Affect was measured before exercise, at 5-minute intervals during exercise and 5 minutes post-exercise. Heart rate, ratings of perceived exertion (RPE) and enjoyment were also measured during each session. Results indicated that there was no difference in psychological affect or enjoyment between the two exercise sessions, although work rate was higher in the preferred condition. However, pre-exercise values of affect played an influential role in the affective response to exercise. These results suggest that allowing fit individuals to select their own exercise intensity may be more beneficial physiologically and psychologically.