Acute Effects of a Single Bout of Walking on Affective Responses in Patients with Major Depressive Disorder.

Exercise programs are considered an effective (add-on) treatment option for depressive disorders. However, little is known about the acute effects of exercise on affective responses in in-patient settings. Therefore, the aim of the present study was to compare the effects of a single 30-min bout of walking on affective responses to a passive control condition in patients with major depressive disorder during treatment in a mental health center. In total, 23 in-patients were exposed to two conditions (duration: 30 min) using a within-subject design: an exercise (light-moderate walking outdoors) and a passive control condition (sitting and reading). Affective responses were assessed based on the Circumplex Model in four phases: pre, during, post, and two hours following the conditions. The main results include a significantly larger pre-post increase in energetic arousal in the exercise condition compared to the control condition, p = 0.012, ηp² = 0.25, but no significantly different pre-follow-up change between conditions, p = 0.093, ηp² = 0.12. Negatively valenced affective responses showed significantly stronger pre-post decreases after the exercise condition compared to the passive control condition, p < 0.036, ηp² > 0.18. Positively valenced affective response activity showed a pre-post increase in the exercise condition and a pre-post decrease in the passive control condition, p = 0.017, ηp² = 0.23. The higher-activated, positively valenced immediate response of light- to moderate-intensity walking may serve as an acute emotion regulation in patients with major depressive disorder and provide a favorable state for adherence to exercise programs.