Only a small amount of research has been conducted examining whether exercise-induced hypoalgesia (EIH) occurs after isometric exercise. Thus, the purpose of this investigation was to examine whether EIH occurred in women after short-duration submaximal isometric exercise and whether the responses were restricted to the exercised hand (ipsilateral) or also occurred in the nonexercised (contralateral) hand. Fourteen healthy women (mean age = 19.5 years) completed 2 sets of submaximal (40% to 50% of max) isometric exercise consisting of squeezing a dynamometer for 2 minutes with the dominant hand. A pressure stimulus was applied to the forefinger on the dominant and nondominant hands for 2 minutes before and after isometric exercise. Participants pressed a button when the stimulus became painful, indicating pain threshold (PT), and also rated the intensity of the stimulus every 15 seconds, using a pain rating scale (PR). Results indicated that there were significant trials effects (P < .05) for PT and PR, but the main effect for hands was not significant (P > .05). PTs were found to be elevated, whereas PRs were reduced for both hands after isometric exercise. It is concluded that submaximal isometric exercise performed for 2 minutes resulted in ipsilateral and contralateral hypoalgesic responses.
Perspective: The findings from the present study demonstrated that short-duration nonexhaustive isometric exercise was associated with hypoalgesic responses in the exercised and nonexercised hands. It appears that short-duration submaximal isometric exercise resulted in generalized (ie, ipsilateral and contralateral) pain-inhibitory responses in healthy young women.