In contemporary society, people experience considerable stress in their daily lives. Therefore, developing effective approaches and convenient means to cope with their mood problems is important nowadays. Physical activity has been consistently reported as a cost-effective way to improve physical fitness, prevent mental illnesses, and alleviate mood problems. In this systematic review, the effects of exercise intensity, duration, and modality on mood change are discussed. Results show that moderate-intensity anaerobic exercise is associated with greater mood improvements. The relationship between exercise duration and mood change is non-linear; A regime of 10- to 30-minute exercise is sufficient for mood improvements. For exercise modality, anaerobic exercise improves mood, but the efficacy of aerobic and mindfulness-related exercises remains to be further examined. In addition to the systematic review of potential moderators, a narrative review of psychological and neurophysiological theories of exercise effects on mood is provided; we have highlighted the central role of neuroplasticity in integrating the two classes of theories. An adoption of neuroimaging techniques in future research is critical to reveal the mechanisms underpinning the therapeutic influence of physical activity on affective responses. Some future research directions are also raised.
Keywords: Anxiety; depression; neuropsychology; stress and coping.