At The Melbourne Sports Medicine Centre we have long been advocates of encouraging exercise and physical activity. The established guidelines regarding the intensity, frequency and type of physical activity are derived from research into maintaining physical health and disease prevention. There is also emerging evidence regarding the benefits of exercise on the brain. It’s becoming apparent that there are some striking similarities regarding the specifics of exercise recommendations for both physical and mental health.
Taking up exercise at any age is worthwhile for the brain. Evidence keeps mounting that excercise is good for the brain and may even slow brain ageing by about 10 years (1). As well as being protective, exercise can also help improve the quality of brain functioning.
A comprehensive review published in the British Medical Journal of Sports Medicine (2) found that exercising for at least 45 minutes several times a week can boost brain power in people aged over 50 regardless of their current state of brain health.
It was determined that aerobic exercise such as swimming, cycling and jogging significantly enhanced cognitive abilities. Cognition refers to the processes involved in acquiring knowledge as well as problem solving and decision making. Resistance training had a pronounced effect on memory and executive function (an umbrella term for the neurologically-based skills involving mental control and self-regulation).
Other exercises like tai chi were also found to show some improvements in cognition. In terms of how much and how often - an exercise session lasting between 45 and 60 minutes of moderate to vigorous intensity of any frequency was good for brain health.
A recent study (3) found that the neurobiological mechanisms underlying the cognitive-enhancing effects of resistance training may be different from those of aerobic training. The literature suggests that resistance training and aerobic training may promote brain function via both divergent and common biological pathways. As a result, it is likely that more comprehensive cognitive benefits will be achieved through balancing your training program with a mixture of aerobic and resistance training.
Exercise can also boost mood by triggering the release of feel-good hormones and chemicals, like endorphins, which can also improve brain health. A 2015 study (4) found that exercise may also be able to prevent the onset of depressive symptoms. Higher levels of physical activity were associated with lower levels of depressive symptoms. The findings suggest that reaching moderate-intensity physical activity levels during midlife may be protective against depressive symptoms.
Another study (5) showed that exercise therapy improves both the physical and mental health of patients with depression. The main mental health benefits resulted from improving body image, patient’s coping strategies with stress, quality of life, and independence in activities of daily living in older adults.
Also, excessive inactivity (or sedentary behaviour) was found to have negative effects on brain function. A comprehensive review of the relevant studies (6) found that whilst it wasn’t easy to measure or define sedentary behaviour precisely, greater amounts of sedentary behaviour are associated with reduced cognitive function over the lifespan. They concluded that limiting sedentary behaviour to less than 2 hours per day whilst also engaging in at least 150 minutes per week of moderate-to-vigorous physical activity may be crucial to maintaining cognitive health throughout ones’ lifespan.
So, there seems to be a coming together of the evidence on the exercise levels that are beneficial for both the mind and body. Much of the emerging evidence on physical activity and mental health has long been suggested for physical health. The current physical activity guidelines for Australian adults (7) are:-
Physical Activity Guidelines
- Doing any physical activity is better than doing none. If you currently do no physical activity, start by doing some, and gradually build up to the recommended amount.
- Be active on most, preferably all, days every week.
- Accumulate 150 to 300 minutes (2 ½ to 5 hours) of moderate intensity physical activity or 75 to 150 minutes (1 ¼ to 2 ½ hours) of vigorous intensity physical activity, or an equivalent combination of both moderate and vigorous activities, each week.
- Do muscle strengthening activities on at least 2 days each week.
Sedentary Behaviour Guidelines
- Minimise the amount of time spent in prolonged sitting.
- Break up long periods of sitting as often as possible.