Emerging evidence has demonstrated an impressive link between physical activity and improved mood. While evidence of beneficial mental health effects of exercise is mounting, doctors, psychologists and other health practitioners are slow to consider exercise and seldom use it as a therapy tool. The present opinion piece argues that, in view of the unsatisfactory mitigation of disease burden and limited long-term effectiveness of the available treatments for depressive disorders, physical exercise and sport deserve far greater consideration and may become a viable measure in the prevention and treatment of depression. The available research findings make a robust case for exercise as a means of protecting and improving mental health as well as physical health.

Depression is highly prevalent across the entire lifespan worldwide and has become the leading cause of burden of disability globally (1). Depression is highly debilitating, causing reduced quality of life and severe functional disability, and because of its high rate of recurrence, depression is difficult to treat (2). The therapies available for major depressive disorder remain less than satisfactory, with a significant proportion of people treated for depression remaining refractory to treatment. The long-term effectiveness of pharmacotherapy, such as the administration of selective serotonin reuptake inhibitors, and psychological treatment, such as cognitive behavioural therapy, remains a matter of debate, and the capacity of these treatments to ameliorate the cumulative burden of depression on society is limited. There is therefore an urgent need to find novel approaches to the prevention and treatment of depression. The major impact of lifestyle on the development of depression often goes unrecognised, and an ever-growing body of research findings suggest a significant contribution of maladaptive lifestyle choices to the pathogenesis of the disorder. Available evidence supports the view that modifiable lifestyle factors, such as diet and physical exercise, should be considered in the management of common mental disorders. Lifestyle-oriented interventions may be capable of reducing the occurrence and severity of depressive disorders and could become targets of health campaigns at population level. Diet and exercise modification has also been suggested as a treatment strategy in the management of depressive disorders arising during the current coronavirus pandemic (3–6). While various nutrients and food bioactives have been claimed to be effective in alleviating depression, evidence of their clinical efficacy is lacking (7–10).