A study on mortality rate in men with varying levels of physical activity, as would be expected, found that the group of men with high levels of physical activity had a 32% reduction in mortality rate compared to those in the sedentary group.
A subset of these sedentary men began exercising at or around age 50 – after 10 years, these men had the same mortality rate as the men who had been actively exercising all along.1
In addition to the many well-known benefits of exercise (prevents chronic disease, reduces cancer risk, beneficial for heart health), there is now accumulating evidence that exercise slows aging at the DNA level.
Telomeres are non-coding regions located on the end of linear chromosomes, and they are shortened with each cell division until the cell no longer divides. For this reason, telomere length is an indicator of cellular aging. Telomere length is maintained in actively dividing cells (such as stem cells and immune cells) by an enzyme called telomerase. There is an inverse association between leisure time exercise energy expenditure and telomere length – meaning that those who exercise regularly have “younger” DNA in their immune cells than those who are sedentary.2-3 A study of middle-aged German track and field athletes found not only longer telomeres in immune cells but also increased activity of the telomerase enzyme and decreased expression of cell-cycle inhibitors – molecules that prevent cell division – in these athletes compared to age-matched untrained individuals.4
Collectively, these studies tell us that exercise not only prevents disease, but promotes longevity, even if we get a late start.
1. Byberg L et al. Total mortality after changes in leisure time physical activity in 50 year old men: 35 year follow-up of population based cohort. BMJ 2009;338:b688
2. Ludlow AT et al. Relationship between Physical Activity Level, Telomere Length,
and Telomerase Activity. Med Sci Sports Exerc. 2008 October ; 40(10): 1764–1771
3. Cherkas LF et al. The association between physical activity in leisure time and leukocyte telomere length. Arch Intern Med. 2008 Jan 28;168(2):154-8.
4. Werner C et al. Physical Exercise Prevents Cellular Senescence in Circulating Leukocytes and in the Vessel Wall. Circulation. 2009 Nov 30. [Epub ahead of print]