The evidence supporting the physical and mental health benefits of exercise across the life span is compelling. In a recent review of prospective population based studies the authors concluded that those practicing regular physical activity at had significantly lower risk of depressive symptoms. Further, the latest Cochrane review of randomized controlled studies on exercise among patients with medical diagnosed depression concluded that exercise had the same antidepressant effect as psychological or pharmacological therapies.
Additionally, observational studies support an association between higher levels of physical activity and a reduced risk of cognitive decline and dementia. Most recently published results from a Norwegian randomized controlled study found that a high intensity functional exercise program improved balance and muscle strength as well as reduced apathy in nursing home patients with medical diagnosed dementia.
Still, there is limited research to guide how much and what sort of exercise is needed to prevent and treat depression and cognitive decline. But both aerobic exercise and resistance exercise may be effective. At the American College of Sports Medicine (ACSM) 62st Annual Meeting, held May 26-30 in San Diego, California Dr. Wenfei Zhu from Arizona State University presented promising results from the American population based REGARDS study. Among 3385 white and black older adults who were followed for almost three years, higher levels of objectively measured moderate-to-vigorous physical activity (MVPA) were independently associated with lower prevalence and incidence of cognitive impairment, and better memory and executive function. Interestingly the authors also found that the amount of MVPA associated with lower risk of cognitive impairment (259 min/week) is >70% higher than the minimal amount of MVPA recommended by current physical activity guidelines. According to the authors future studies are needed to determine if less amounts of physical activity than what was found to be protective in the REGARDS study are also related to lower cognitive impairment in older adults.
The biological mechanisms behind the positive effects from exercise on mental health are far from clear.
What is obviously evident is that more translational research is needed to answer all our questions about the association between exercise and mental health. However, the scientific evidence so far should be taken seriously. Instead of comparing our brain to a computer it should also be thought of as a muscle which can, and preferably should be, strengthened with physical exercise.
Linda Ernstsen Post Doc at CERG