Men report greater pain relief following sustained static contractions than women when matched for baseline pain

The authors compared men and women with similar experimental pain at rest to determine if sex differences in pain relief occurred following fatiguing isometric contractions. Men (n=13) and women (n=13) were matched retrospectively in pairs from a large database based on baseline pain perception. Pain (threshold and ratings) was measured with a noxious stimulus before and after quiet rest or a submaximal isometric contraction. Following quiet rest, there was no change in pain ratings or pain threshold for either men or women. Following the isometric contraction, pain thresholds increased for both men and women, whereas pain ratings decreased for men only. Pain reports prior to exercise may contribute to sex differences in pain relief following exercise.