Exercise as medicine was prescribed as early as 600 BC by Susrata, an Indian physician¹. Susrata believed that moderate exercise was crucial for healthy digestion, skin complexion, aging, and physical development¹. Since then, the scientific method has proven many of the ancient physician's presuppositions and continues to reveal the healthful benefits of physical activity². This week, we will explore the benefits of physical activity on depression.
It is a well established finding that individuals that are less fit suffer from greater symptoms of depression³⁻⁵ More specifically, exercise reduces the severity of depression while also preventing its onset⁶⁻⁷. In one study, researchers found that there were no differences in depressive symptoms between an exercise group that was prescribed 3 weekly aerobic workouts and an antidepressant (sertraline) group 4 months following the intervention⁷. After 10 months, decreased depressive symptoms and relapse rates were observed among the exercise group⁸.
There are numerous mechanisms that potentially mediate the beneficial effects of exercise on depression. Participation in a regular exercise routine may be met with positive feedback from broader society and establish a sense of normalcy in depressed individuals². Moreover, exercising at high intensities makes it very difficult to ruminate on one's personal issues². Physical activity may combat fatigue which is characteristic among depressed individuals². Furthermore, increased perspiration and heart rate during physical activity teaches depressed individuals that such sensations are normal². Finally, exercise may increase hippocampal (the stress regulation center of the brain) volume which has been demonstrated to be shrunken among individuals suffering from depression⁹⁻¹⁰.
There are no conclusive exercise prescriptions for testing depression². Therefore, it is advised that readers follow the public health guidelines of 150 minutes of moderate to vigorous physical activity per week².
References
Bhishagratna, K. K (1996). Sushruta Samhita: Volume 1. Chowkhamba Sanskrit Series Office.
Pedersen, B. K., & Saltin, B. (2015). Exercise as medicine - evidence for prescribing exercise as therapy in 26 different chronic diseases. Scandinavian Journal of Medicine & Science In Sports, 25 Suppl 3, 1–72. https://doi.org/10.1111/sms.12581
Thirlaway, K., & Benton, D. (1992). Participation in physical activity and cardiovascular fitness have different effects on mental health and mood. Journal of Psychosomatic Research, 36(7), 657–665. https://doi.org/10.1016/0022-3999(92)90055-7
Galper, D. I., Trivedi, M. H., Barlow, C. E., Dunn, A. L., & Kampert, J. B. (2006). Inverse association between physical inactivity and mental health in men and women. Medicine and Science In Sports and Exercise, 38(1), 173–178. https://doi.org/10.1249/01.mss.0000180883.32116.28
Tolmunen, T., Laukkanen, J. A., Hintikka, J., Kurl, S., Viinamäki, H., Salonen, R., Kauhanen, J., Kaplan, G. A., & Salonen, J. T. (2006). Low maximal oxygen uptake is associated with elevated depressive symptoms in middle-aged men. European Journal of Epidemiology, 21(9), 701–706. https://doi.org/10.1007/s10654-006-9038-5
Sui, X., Laditka, J. N., Church, T. S., Hardin, J. W., Chase, N., Davis, K., & Blair, S. N. (2009). Prospective study of cardiorespiratory fitness and depressive symptoms in women and men. Journal of Psychiatric Research, 43(5), 546–552. https://doi.org/10.1016/j.jpsychires.2008.08.002
Blumenthal, J. A., Babyak, M. A., Moore, K. A., Craighead, W. E., Herman, S., Khatri, P., Waugh, R., Napolitano, M. A., Forman, L. M., Appelbaum, M., Doraiswamy, P. M., & Krishnan, K. R. (1999). Effects of exercise training on older patients with major depression. Archives of Internal Medicine, 159(19), 2349–2356. https://doi.org/10.1001/archinte.159.19.2349
Babyak, M., Blumenthal, J. A., Herman, S., Khatri, P., Doraiswamy, M., Moore, K., Craighead, W. E., Baldewicz, T. T., & Krishnan, K. R. (2000). Exercise treatment for major depression: maintenance of therapeutic benefit at 10 months. Psychosomatic Medicine, 62(5), 633–638. https://doi.org/10.1097/00006842-200009000-00006
Campbell, S., Marriott, M., Nahmias, C., & MacQueen, G. M. (2004). Lower hippocampal volume in patients suffering from depression: a meta-analysis. The American Journal of Psychiatry, 161(4), 598–607. https://doi.org/10.1176/appi.ajp.161.4.598
Pajonk, F. G., Wobrock, T., Gruber, O., Scherk, H., Berner, D., Kaizl, I., Kierer, A., Müller, S., Oest, M., Meyer, T., Backens, M., Schneider-Axmann, T., Thornton, A. E., Honer, W. G., & Falkai, P. (2010). Hippocampal plasticity in response to exercise in schizophrenia. Archives of General Psychiatry, 67(2), 133–143. https://doi.org/10.1001/archgenpsychiatry.2009.193