The influence of exercise on dental pain thresholds and the release of stress hormones.

Different levels of exercise (50-200 W) were produced by a bicycle ergometer. In all six subjects the heart rate and blood pressure were increased with increasing work load. Dental pain thresholds tended to increase with increasing work load, too. Plasma ACTH levels were above the normal range during the whole experiment in all subjects, whereas plasma cortisol and prolactin levels were elevated only in one subject. Growth hormone levels had a tendency to elevation at 200 W. There was no correlation between the release of cortisol, prolactin or ACTH and the dental pain threshold elevation. However, there was significant correlation between the release of growth hormone and the dental pain threshold elevation. The results indicate that physical exercise at submaximal work loads is enough to produce a pain threshold elevation in some subjects, with a minor coactivation of stress mechanisms.