Thirty-eight men and 35 women completed diaries of exercise, mood, and the experience and appraisal of daily stressors over 12 consecutive days. It was hypothesized that exercise would be associated with positive moods and with the experience of fewer daily stressors. Positive moods were rated higher and depression lower on exercise days than no-exercise days. Participants low in trait anxiety reported fewer stressful events on the days on which they exercised. Those with strong personal (health, physical appearance, and mood) motives for exercise reported more stressful daily events overall; in addition, they experienced more potentially stressful events as nonstressful on the days during which they engaged in physical exercise. The results are discussed in relation to the acute after-effects of exercise on mood and stress responsivity and the long term of psychological benefits of regular exercise.