Exercise, the Brain, and Mental Health

Key Points

• Exercise is neuroprotective and neurogenic.
• Exercise is associated with reduced risk of Alzheimer’s and Parkinson’s diseases
• Exercise improves mood and reduces depression and anxiety.
• Withdrawal of exercise results in depressive symptoms
• Exercise improves cognition.

Exercise is broadly neuroprotective. It increases brain-derived neurotrophic factor (leading to greater repair and creation of neurons), improves neuronal insulin sensitivity, reduces neuroinflammation, and enhances neural mitochondria function.^{1, 2}

Neurodegeneration

Exercise, especially when combined with diet, can improve brain health and reduce the risk of Alzheimer’s disease,² and Parkinson’s disease,³ and reduce the deterioration of motor and cognitive function in Parkinson’s.³

Mood, depression, and anxiety

Exercise also improves mood and reduces depression in young people,⁴ and improves symptoms in people with schizophrenia.⁵ Even moderate-intensity aerobic exercise (45 min 3 times per week) significantly reduces depression,⁶ while the withdrawal of exercise consistently results in depressive symptoms and anxiety, with the greatest effect seen when exercise is halted for > 2 weeks.⁷

Cognition

All types of exercise; aerobic, resistance, and mind-body exercises are associated with improved cognition,^{8, 9}  especially in the domains of processing speed, attention, and executive function.⁹ Studies also report significant positive effects of physical exercise on cognition, agitation, mood, mobility, and functional ability for people with dementia.¹⁰

References

1.         Zhu MM, Lai JSM, Choy BNK, Shum JWH, Lo ACY, Ng ALK, et al. Physical exercise and glaucoma: a review on the roles of physical exercise on intraocular pressure control, ocular blood flow regulation, neuroprotection and glaucoma-related mental health. Acta Ophthalmologica. 2018;96(6):e676-e91.

2.         Baranowski BJ, Marko DM, Fenech RK, Yang AJT, MacPherson REK. Healthy brain, healthy life: a review of diet and exercise interventions to promote brain health and reduce Alzheimer’s disease risk. Applied Physiology, Nutrition, and Metabolism. 2020;45(10):1055-65.

3.         Cammisuli DM, Bonuccelli U, Daniele S, Martini C, Fusi J, Franzoni F. Aerobic Exercise and Healthy Nutrition as Neuroprotective Agents for Brain Health in Patients with Parkinson’s Disease: A Critical Review of the Literature. Antioxidants. 2020;9(5):380.

4.         Pascoe M, Bailey AP, Craike M, Carter T, Patten R, Stepto N, et al. Physical activity and exercise in youth mental health promotion: a scoping review. BMJ Open Sport & Exercise Medicine. 2020;6(1):e000677.

5.         Kim M, Jeon J. The effect of exercise on physical and mental health for adults with schizophrenia: A review of clinical aerobic exercise. Ethiopian Journal of Health Development. 2020;34(1).

6.         Morres ID, Hatzigeorgiadis A, Stathi A, Comoutos N, Arpin-Cribbie C, Krommidas C, et al. Aerobic exercise for adult patients with major depressive disorder in mental health services: A systematic review and meta-analysis. Depression and Anxiety. 2019;36(1):39-53.

7.         Weinstein AA, Koehmstedt C, Kop WJ. Mental health consequences of exercise withdrawal: A systematic review. General Hospital Psychiatry. 2017;49:11-8.

8.         Batsis JA, Roderka MN, Rauch VK, Seo LM, Li X, DiMilia PR, et al. Impact of Diet and Exercise on Weight and Cognition in Older Adults: A Rapid Review. American Journal of Health Promotion. 2021;35(3):456-66.

9.         Gomes-Osman J, Cabral DF, Morris TP, McInerney K, Cahalin LP, Rundek T, et al. Exercise for cognitive brain health in aging. A systematic review for an evaluation of dose. 2018;8(3):257-65.

10.       Brett L, Traynor V, Stapley P. Effects of Physical Exercise on Health and Well-Being of Individuals Living With a Dementia in Nursing Homes: A Systematic Review. Journal of the American Medical Directors Association. 2016;17(2):104-16.