The influence of submaximal isometric exercise on temporal summation of heat pain

Abstract

Numerous studies have indicated an attenuation of pain following exercise in healthy young adults, and this phenomenon has been referred to as exercise-induced hypoalgesia. Little is known, however, about the effect of short duration isometric exercise (i.e., static muscular contraction) on temporal summation of pain. Thus, the purpose of this study was to examine the influence of submaximal isometric exercise on the temporal summation of heat pain in men and women. Fifty-two men and women with a mean age of 21 yrs (sd = 3) participated in this study. Ten heat pulses were applied to the thenar eminence of the dominant hand using a standardized temporal summation protocol. Participants rated the intensity of the heat pulses using a 0-100 rating scale at baseline, before, and following isometric exercise which consisted of squeezing a hand dynamometer at 25% of maximum for 3 minutes. The data were analyzed with a 2 (sex) X 3 (trials: baseline, pre, and post) X 3 (pulses: 1, 5, and 10) repeated measures ANOVA. The results indicated a significant reduction (p < 0.05) in pain ratings following isometric exercise. The magnitude of reduction in temporal summation of heat pain was moderate (effect sizes for the men = 0.37-0.40 and for the women = 0.57-0.64). It is concluded that short duration, submaximal isometric exercise was associated with a reduction in temporal summation of heat pain in men and women. Supported by NIH grant R21AR057159. Numerous studies have indicated an attenuation of pain following exercise in healthy young adults, and this phenomenon has been referred to as exercise-induced hypoalgesia. Little is known, however, about the effect of short duration isometric exercise (i.e., static muscular contraction) on temporal summation of pain. Thus, the purpose of this study was to examine the influence of submaximal isometric exercise on the temporal summation of heat pain in men and women. Fifty-two men and women with a mean age of 21 yrs (sd = 3) participated in this study. Ten heat pulses were applied to the thenar eminence of the dominant hand using a standardized temporal summation protocol. Participants rated the intensity of the heat pulses using a 0-100 rating scale at baseline, before, and following isometric exercise which consisted of squeezing a hand dynamometer at 25% of maximum for 3 minutes. The data were analyzed with a 2 (sex) X 3 (trials: baseline, pre, and post) X 3 (pulses: 1, 5, and 10) repeated measures ANOVA. The results indicated a significant reduction (p < 0.05) in pain ratings following isometric exercise. The magnitude of reduction in temporal summation of heat pain was moderate (effect sizes for the men = 0.37-0.40 and for the women = 0.57-0.64). It is concluded that short duration, submaximal isometric exercise was associated with a reduction in temporal summation of heat pain in men and women. Supported by NIH grant R21AR057159.