Greater depression severity predicts improvements in physical exhaustion following aerobic exercise in youth with bipolar disorder.

OBJECTIVE: Despite the potential benefits of exercise on mood and physical health in bipolar disorder (BD), exercise rates in youth with BD remain low. Given that exercise-induced feelings predict future exercise participation, the present study examined the association of baseline depression and mania severity with exercise-induced feelings in youth with BD. METHOD: Fifty-two youth with BD (17.3 ± 1.3 years) completed semi-structured diagnostic and mood symptom rating scales. The Exercise-Induced Feeling Inventory (EFI) was completed before and after a single session of aerobic exercise. Multiple linear regression was used to examine associations of baseline depression and mania severity with changes in EFI subscales, controlling for age and sex. To explore heterogeneity in physical exhaustion responses post-exercise, analyses also compared clinical characteristics across subgroups with reduced (n = 14), unchanged (n = 22), and increased (n = 16) physical exhaustion post-exercise. RESULTS: Greater depression symptom severity was associated with moderate-large reductions in physical exhaustion post-exercise (β = -0.44, p = 0.002) among youth with BD, explaining 17.2% of variance. Participants with reduced exhaustion following exercise had greater baseline irritable mood (p = 0.04), anhedonia (p = 0.03), and fatigue (p = 0.02), compared to those with increased exhaustion following exercise. Mania symptom severity was not associated with changes in any EFI subscales. DISCUSSION: Youth with greater depression severity, including fatigue, experienced reduced exhaustion following aerobic exercise. Given that fatigue is a common barrier to exercise, this finding highlights a missed opportunity for youth experiencing depression to benefit from exercise. Current findings have potential implications for exercise-related psychoeducation and motivational-enhancement strategies in youth with BD.