Fitness level, but not sex, affects exercise-induced pain modulation

A previous study by the researchers (Nold et al., 2025) explored how exercise-induced pain modulation is affected by sex, fitness level, and drug treatment. They found that males experienced increased pain tolerance after high-intensity exercise, which decreased when a certain drug was introduced. However, this effect was not observed in females. These findings prompted further research to understand if and how much exercise-induced pain modulation is influenced by fitness level and/or sex.

In this current study, the researchers focused on a group of all-female participants with high fitness levels (N=21) and examined the impact of exercise intensity and stimulus intensity on heat pain. Their results revealed an interaction between exercise intensity and stimulus intensity, indicating greater pain relief after high-intensity exercise, particularly at the highest stimulus intensity.

Although pressure pain ratings did not reach statistical significance, a similar pattern was observed. These findings suggest that high-fitness females also exhibit exercise-induced pain modulation when engaging in high-intensity exercise compared to low-intensity exercise.

Moreover, the researchers combined the data from the current study with the previous one, which demonstrated that both fitness level and sex do not moderate exercise-induced pain modulation in heat pain. These findings support the notion that exercise-induced pain modulation is primarily influenced by fitness level, rather than sex.