Photo courtesy of Tanner Johnson

Photo courtesy of Tanner Johnson

There is no magic potion to counter aging…at least for now. Aging is a complex, multifactorial biological phenomenon which we still do not fully understand how to treat. While we know specific genes and interventions that increase lifespan in model organisms such as rodents, flies, and worms, we do not yet fully understand how to translate those findings to humans. Aging is the single largest risk factor for most chronic diseases that afflict the developed world, greater than high blood pressure, greater than high cholesterol, and greater than obesity. Unfortunately, there are no pills or simple dietary changes that prevent or delay the plethora of diseases we acquire as we age. So what can we do? What is the best defense until an anti-aging therapy is developed? In a word, exercise.

While many people know exercise is beneficial to human health, there is another way of looking at it; exercise is medicine. The American College of Sports Medicine is currently promoting their “Exercise Is Medicine” campaign that highlights the benefits of regular physical activity. Collectively, research indicates that physical activity extends median lifespan by 4-6 years in humans, but does not increase maximal lifespan. In addition to lifespan, physical activity increases the years of quality life by decreasing the likelihood of obtaining a number of different chronic diseases. Many of these chronic diseases are aging related diseases, or diseases whose prevalence increase in likelihood as one ages. Such diseases include cardiovascular diseases, metabolic diseases, osteoporosis, and certain types of cancer such as breast and prostate cancer.

While we know that increased physical activity is associated with lower rates of chronic disease, we cannot definitively say that physical inactivity is the ultimate cause of these diseases as nutrition, genetics, and other environmental factors also contribute to the development of chronic diseases. For instance, individuals who are highly active throughout their life completely prevent the decline of some cardiovascular functions (such as endothelial dysfunction, left ventricular heart mass loss, and ventricular stiffness) and maintain insulin sensitivity until at least the age of 70. Conversely, living a physically active lifestyle attenuates loss of bone density, maximal cardiovascular fitness, and skeletal muscle mass/power, but is insufficient to completely prevent. Lastly, age-related declines in function such as the loss of various senses (hearing, taste, vision) and maximal heart rate are not prevented by high levels of lifetime physical activity.

Research has shown that it is never too late to benefit from being physically active. For instance, one study showed that elderly men (age 70-82) that transitioned from unfit to fit showed a decrease in mortality risk by 50%. Similarly, an improvement in insulin sensitivity and muscle strength in older individuals is seen upon initiation of an exercise program. While physical activity primarily engages the skeletal muscle and cardiovascular systems, those are not the only tissues that receive physiological benefit. In the brain, neurogenesis (the creation of new neurons) occurs in response to physical activity, improving memory and cognitive functioning.

So in summary, while we cannot cure aging, we can certainly ameliorate some aspect of the process by leading a physically active lifestyle. It is important to know that it is never too late to start an exercise program and while more is typically better, even small increases in physical activity levels have profound benefits on overall health. So while you should consult your physician for specifics, the best exercise program is the one that you are inspired to do. Whether you prefer to walk, swim, ride, or lift, get off the couch and make the personal investment in healthy aging!