Abstract # 3110 Reward functioning following an acute bout of exercise among healthy adults

Abstract

Exercise is thought to exert beneficial effects on reward functioning, as it alters neurotransmitter levels in reward-related circuits. However, there has been little investigation of the effect of exercise on reward functions in humans. We hypothesized a bout of exercise would increase motivation for and pleasurable responses to rewards in healthy adults. We also examined possible moderators of exercise’s effects. Thirty-five participants completed exercise (20 min run at 105% of lactate threshold intensity) and rest (20 min sit) sessions in a randomized, counterbalanced order. After each activity, participants completed measures of motivation for (Effort Expenditure for Rewards Task) and pleasurable responses to (International Affective Picture System Task) rewards. Exercise did not increase motivation for or pleasurable responses to rewards on average. However, there was a moderating effect of years running, as individuals who had been runners for more years showed increased motivation for rewards after exercise, while individuals with less years running showed decreases. Further, baseline heart rate variability negatively correlated with the effects of exercise on arousal. As this was not specific to picture type, it suggests a dysregulation of emotional responses after exercise in individuals with low HRV. Our results indicate that baseline characteristics may have important moderating influences on the effect of exercise on emotional functioning. Previous experience with the exercise used should be examined as a possible moderator in exercise interventions.