The link between fitness and longevity

05.30.14 |

Our choices can directly affect how long we live.

Early science perpetuated a fallacy that our life span is predetermined—that we have some kind of internal clock, and when it strikes midnight, we die.

Clearly, genetics are important, and they do have some influence on how long you’re going to live. But studies of identical twins raised in different environments and exposed to different lifestyles have demonstrated that genetics determine only about 20 to 30 percent of your health and longevity.

The other 70 to 80 percent is dependent on your own lifestyle and daily behaviors, making your choices the dominant factor in how long you are likely to live.
While a wide range of factors and choices contribute to your longevity, one surefire way to make a dramatic difference in your health is to introduce and maintain regular exercise. In addition to the many benefits of an active lifestyle, like improving heart health and fighting obesity, the very presence of muscle has been linked to longevity.

For example, a 2013 study (published in The American Journal of Medicine) found that among older adults “total mortality was significantly lower in the fourth quartile of muscle mass index compared to the first.” In other words, the older adults that had more muscle mass were more likely to live longer.

Here’s the challenge

Beginning at age 20, we lose about a pound of muscle each year. And what replaces those muscle cells? Fat cells.

Each pound of muscle consumes around 50 to 70 calories a day. Fat, on the other hand, consumes much less energy—less than 10 percent of the energy that muscle uses.

That means that as we lose muscle over the years, our energy expenditure decreases. And when energy expenditure decreases, fat accumulation increases, creating a vicious cycle.

This is why the loss of muscle mass and muscle strength—known as sarcopenia of aging—is linked to pre-obesity, and obesity contributes to a downward spiral of non-sickness and disease.

If you’re an older adult—or perhaps are thinking about an older adult in your life that you care about—you might be thinking that a powerlifting routine or an intense jogging schedule is just not an option. Don’t worry. You don’t need to be a body builder to successfully defeat sarcopenia of aging.

In support of this, a 2014 BMJ (formerly the British Medical Journal) study used grip strength, the speed at which participants could stand from sitting, and their ability to balance while standing as indicators of fitness for subjects from age 53 to 66. The researchers found that “lower levels of physical capability at age 53 and inability to perform capability tests are associated with higher rates of mortality.”

Think about that

If you could live a longer life simply by improving your grip, how well you can stand, and by working on your balance, think about how much of an impact you could make on your health with a regular walking program.

You don’t need an extreme fitness routine to maintain your muscle mass as you age. Staying active through little choices like taking the stars, washing the dishes by hand instead of using the dishwasher, and by making an effort to go for a walk a few times a week can help you fight obesity and create health. Your small efforts to be active will add up, but you have to keep making them. Don’t get sucked into a life of inactivity. To keep the muscle you have, you have to use it!

Looking for ideas and strategies for incorporating more Habits of Health into your life? Take Dr. A’s 30-Day Challenge—completely free—to get daily emails that guide you through his proven system for creating health.