Brief submaximal isometric exercise improves cold pressor pain tolerance

Exercise-induced hypoalgesia (EIH), or the inhibition of pain following physical exercise, has been demonstrated in adults, but its mechanisms have remained unclear due to variations in methodology. This study aimed to address methodological imitations of past studies and contribute to the literature demonstrating the generalizability of EIH to brief submaximal isometric exercise and cold pressor pain. Young adults (n = 134) completed a baseline cold pressor trial, maximal voluntary contraction (hand grip strength) assessment, 10-min rest, and either a 2-min submaximal isometric handgrip exercise or a sham exercise in which no force was exerted, followed by a cold pressor posttest. Results indicated that cold pressor pain tolerance significantly increased during the exercise condition, but not during the sham exercise condition. Exercise did not affect pain intensity and marginally affected pain unpleasantness ratings. These findings suggest that submaximal isometric exercise can improve cold pressor pain tolerance but may have an inconsistent analgesic effect on ratings of cold pressor pain.