Mood alteration from treadmill running and its relationship to beta-endorphin, corticotropin, and growth hormone

We examined the effects of running on mood alteration in males and females and its relationship to changes in beta-endorphin (B-EN), corticotropin (ACTH), and growth hormone (GH). Thirteen males and ten females ran on a treadmill for 30 min at 80% of previously determined maximum heart rate. Five plasma samples were obtained through an indwelling catheter before exercise (-30 and 0 min), during exercise (15 min), at exercise completion (+30 min), and after 30 min of recovery (R30); the Profile of Mood States (POMS) inventory was administered at -30 and +30. Composite mood improved after the run for both males and females withput concomitant rise in B-EN. For males but not females, an increase in mood was associated with lower B-EN (r = 0.65) and ACTH (r = 0.65) and this relationship was also significant prior to exercise for B-EN (r = 0.74) and ACTH (r = 0.81). It appears that an increase in peripheral beta-endorphin concentration may not be a major contributor to improved mood in response to exercise, but is an indicator of negative mood in males.