More Exercise, Less Aging?
By Jill Horn
Successful aging implies growing old in the absence of chronic illness while maintaining mental and physical well-being and successfully adapting to the changes of increased age. It is well-known that lifestyle factors can influence the process of aging in either positive or negative ways through epigenetic and other pathways. In addition to a healthy diet and psychosocial well-being, it has been repeatedly shown that regular physical exercise fundamentally influences longevity in a positive manner. As confirmed by a variety of studies, physical activity may reverse or slow the effects of aging on various physiological functions. The preservation of these physiological functions into old age is mainly attributed to metabolic health, cardiovascular risk reduction and the psychological benefits that exercise brings about which correspond to reduced overall depression and anxiety.
“…physiological and psychological benefits of exercise, independently of weight, support longevity and decrease mortality risk.”
Converging evidence suggests that the physiological and psychological benefits of exercise, independently of weight, support longevity and decrease mortality risk. Scientific studies have found that regular physical exercise is associated with a reduced risk of many of the diseases of our current epidemic of chronic noninfectious diseases, including cardiovascular disease, stroke, type 2 diabetes, osteoporosis, breast cancer, colon cancer, anxiety, and depression. As the absence of pathology is a key component of successful aging, these effects may also bring about a reduction in mortality risk and improved longevity. In fact, in another study it was found that a physically active group showed a life expectancy increase of eight years when compared to a sedentary control group of the same age people. Further supporting these findings, a meta-analysis confirms a 30% reduction in the risk of cardiovascular mortality in people who regularly exercise when compared to inactive people.
“…regular physical exercise can be considered a more important component of healthy aging than body weight…”
Another recent study found that the cardiometabolic improvements of exercise are independent of weight loss, and while exercise is substantially backed by scientific evidence to reduce mortality risk, weight loss as an independent variable is not consistently associated with such a risk reduction. Therefore, regular physical exercise can be considered a more important component of healthy aging than body weight or even body mass index.
“…as little as one hour of aerobic exercise three times per week resulted in improvements in specific cognitive functions…”
Evidence further suggests that physical activity may prevent cognitive decline, another key component of healthy aging. Emerging evidence supports a positive effect of exercise on cognition preservation in the elderly, both short-term and long-term. For example, in a recent clinical study, as little as one hour of aerobic exercise three times per week resulted in improvements in specific cognitive parameters over just a six-week study period. Despite these promising findings, more research is needed to confirm the effects of exercise on reduction of cognitive decline.
“…physical activity seems to result in preserved telomere length.”
Besides the cardioprotective and mental health enhancing effects of exercise, its influence on longevity and the slowing of the aging process is further attributed to the maintenance of telomere length. Chromosomal telomere length has long been used as a measure of biological age since the activity of the telomerase enzyme decreases with chronological age. Less telomerase activity corresponds to a reduction in telomere length, which is used as a biological indicator of age, while longer telomeres are associated with youth. A recent study investigated the effects of exercise on telomere length and found that physical activity seems to result in preserved telomere length. Subjects who were less physically active were found to have shorter telomeres by an average of 200 nucleotides when compared to people who engaged in regular exercise.
“…current guidelines suggest engaging in moderate-intensity aerobic exercise for a minimum of 30 min on 5 days/week or vigorous intensity aerobic activity for 20 min on 3 days/week.”
Aiming at putting theory into practice, many scientists and physicians have been trying to figure out the perfect amount of exercise for optimal health and longevity. According to a recent review, current guidelines suggest engaging in moderate-intensity aerobic exercise for a minimum of 30 min on 5 days/week or vigorous intensity aerobic activity for 20 min on 3 days/week. In addition to that, resistance training for strengthening muscles should be performed more than 2 days/week, and flexibility and stretching exercises should be included more than 2 days/week as well. However, excessive strenuous exercise more than 10 hours per week has been shown to actually reduce health benefits. As previously discussed in this newsletter, intense physical exercise in the form of ultramarathon or triathlon participation is perceived by the brain as a threat to homeostasis, triggering an allostatic stress response which can lead to systemic immune activation. On the other hand, despite the recommended amount of a minimum of 30 min of moderate intensity aerobic activity 5 days/week, it has been shown that even just as little as 15 min per day 6 days/week was associated with reductions in mortality.
Most importantly, finding an exercise routine that works for you; one which adds balance to your schedule and connects you with friends and/or nature will be the most important aspect when it comes to reaping the health and longevity benefits of physical activity in the long run.
Jill Horn is an international student from Switzerland on a pre-med track, currently majoring in Neuroscience at UCLA.