The purpose of this study was to evaluate the impact of current physical activity on the affective and mood state response to acute moderate exercise in individuals with major depressive disorder (MDD). Twenty-nine individuals with MDD performed a moderate-intensity exercise bout for 30 minutes and rated their affective valence and depressive mood states at six time points: PRE-, MID-, POST-exercise as well as at 25-, 50-, and 75-minutes post-exercise. The affective valence was measured with the Feeling Scale (FS) while the depressive mood states were measured with the Profile of Mood States Depression subscale (POMS-D). Participants were divided into Low and High physical activity (PA) based on their average steps per day.

There was no significant influence of PA level on the affective valence response to a moderate-intensity exercise session (p = .26) nor a group main effect (p = .96). There was also no significant difference in the MID-PRE change score between individuals in Low PA and those in High PA (p = .42), nor in the POST-PRE change score (p = .71). The largest effect size between Low PA and High PA was found at PRE (g = 0.42). There was also no evidence that PA significantly influenced the mood state response to exercise (p = .75) nor a group effect (p =.85). The largest effect size between Low PA and High PA in the POMS-D was at POST (g = 0.28).

While affective valence and depressive mood states change during and after an exercise session, regular physical activity levels do not appear to be associated with the variability of this response in adults with MDD. Ultimately, understanding what factors influence how an individual feel during an exercise session should aid adherence to exercise programs, and therefore, the potential success of prescribing exercise as a treatment of MDD.