No evidence of a relationship between regular physical exercise and cardiac interoception

Cardiac interoception, the ability to sense and process cardiac afferent signals, has been shown to improve after a single session of acute physical exercise. However, it remains unclear whether repetitive engagement in physical exercise over time leads to long-term changes in cardiac interoceptive accuracy and neural activity associated with the processing of afferent cardiac signals. In this study, we aimed to investigate this hypothesis through two cross-sectional studies, categorizing participants as high or low fit based on physical fitness (Study I) or self-reported physical activity levels (Study II). Interoception was assessed using the Heart-Evoked Potential (Studies I and II), the Heartbeat Counting task (Study II), and the Rubber Hand Illusion (Study II). Despite consistent between-group differences in electrocardiogram recordings in both studies, there were not statistically significant between-group differences in any of the measures of interoception. Consequently, our results do not provide evidence to support the notion that regular physical exercise leads to an increase in cardiac interoception.