Post-exercise analgesia: replication and extension.

This study was designed to investigate whether post-exercise analgesia occurs following an ad lib exercise routine. All of the 17 male participants exercised on a regular basis. In an exercise setting (student gymnasium) they participated in 20 min of self-selected exercise, while in the neutral setting (laboratory) they rested quietly for 20 min. Pain was induced via the gross pressure device. Pain threshold and pain tolerance were measured twice, with an interval of 20 min, in both the exercise and the neutral setting. Pain threshold was stable in the exercise setting. A significant increase in pain tolerance followed the 20 min bout of exercise, indicating a post-exercise analgesic response. These results support the prediction that the analgesic effect of exercise is not limited to controlled experimental conditions, but generalizes to naturally occurring situations.