A new study published in The British Medical Journal compares the effects of varying amounts of exercise on preventing depressive symptoms in older adults. There has been limited research to date on the long-term mental health effects of exercise within older adult populations. Utilizing a prospective approach, the authors compared four types (duration/frequency) of moderate exercise and found evidence that persistent low amounts of exercise can have physical and psychological benefits for older adults.
Persistent low-volume practice (less than 15 minutes of moderate intensity exercise per day) was shown to have preventive effects on depressive symptoms, similar to the effects of 30 minutes of exercise, the authors explain.
“These findings suggest that short, age-friendly exercise types may benefit older adults both physically and psychologically.”
Exercise has the potential to be an effective approach to both treating and preventing depressive symptoms. As the authors point out, there is evidence of hippocampal neurogenesis and as a result of exercise, which can have anti-depressive effects. Exercise has also been linked with increases in B-endorphins, vascular endothelial growth factor, brain-derived neurotrophic factor, and serotonin.
The efficacy of exercise interventions has been demonstrated in studies of yoga for depression and decreasing depressive symptoms in children. Moreover, a meta-analysis of 25 trials found that the effect of exercise on reducing depressive symptoms has been underestimated. Much of the research on the impact of exercise, however, has not focused on the effects of exercise on an older adult population.
Data from the Taiwan Longitudinal Study on Aging (TLSA) was utilized in this analysis. They included 2673 adults aged 65 years and over. The impact of 4 different types/amounts of exercise on depression was assessed. Depression ratings were collected with the Center for Epidemiologic Studies Depression Scale (CESD) and categorized into (1) no depressive symptoms, (2) lower level of depressive symptoms, and (3) higher level of depressive symptoms.
The four exercise conditions all were of moderate intensity and covered: (1) 15 minutes, three times/week, (2) 30 minutes, three times/week, (3) 15 minutes, six times/week, and (4) 30 minutes, six times/week. Physical activity was assessed by asking participants about frequency, duration, and intensity based on sweating level (none, a little, a lot and none of the above) after exercise. Further, patterns of exercise consistency were calculated to explore the effect of changes in exercise habits. These were classified as; low pattern, declining pattern, increasing pattern, and persistent pattern.
Data on participants’ gender, age, marital status, the level of education, economic satisfaction, employment status, physical function, social participation, emotional support, self-rated health, smoking, and chronic conditions was also gathered.
On average, the participants were 74.4 years old, and 54.5% were male. Only exercise at the level of 6 times per week, 30 minutes in duration was found to have a significant effect on reducing high levels of depressive symptoms. High levels of depressive symptoms were also positively predicted by physical function, emotional support, self-rated health and economic satisfaction.
When examining the effect of changes in exercise models, controlling for other determining factors, and looking at the interactions of time and patterns of activity, results showed that only persistent patterns of exercise have a protective effect on higher levels of depressive symptoms.
In this analysis, even moderate intensity from 15 minutes, 3 times a week was protective, however. The results of this study suggest those who practice consistent exercise of moderate intensity, at least 15 minutes, three times a week are likely to have lower levels of depressive symptoms.
Chang Y, Lu M, Hu I, et al Effects of different amounts of exercise on preventing depressive symptoms in community-dwelling older adults: a prospective cohort study in Taiwan BMJ Open 2017;7:e014256. doi: 10.1136/bmjopen-2016-014256 (Abstract)