Perceived exertion reflects exercise-induced pain rather than psychological characteristics in recreational endurance athletes

In endurance exercise, psychological characteristics such as anxiety, depression, and personality traits may influence ratings of perceived exertion (RPE) and exercise-induced pain (EIP). However, it remains unclear whether these characteristics are independently associated with session RPE (sRPE) or influence the relationship between sRPE and EIP. This study examined the association between sRPE and EIP in recreational endurance athletes and explored the potential role of psychological characteristics in this relationship. A total of 144 recreational endurance athletes (41 trail runners, 73 hikers) were enrolled at organized outdoor endurance events conducted on non-technical terrain (≤ T2, Swiss Alpine Club classification) at altitudes below 2500 m during the summer season. Participants rated maximum pain intensity, average pain intensity, and pain unpleasantness, which were averaged to derive a composite EIP score. Psychological assessments included the personality traits, pain catastrophizing, anxiety sensitivity, and symptoms of anxiety and depression. External exercise load was quantified using effort-adjusted pace and exercise duration. EIP was the only variable consistently associated with sRPE, with each one-unit increase corresponding to an approximately 13-19% increase in perceived exertion. This association remained significant after adjustment for all covariates, suggesting that sRPE may primarily reflect concurrent EIP rather than external load or psychological characteristics.