Year in Fitness: How Exercise Keeps Us Young

Some of the biggest news in exercise science this year concerned the tiniest impacts from physical activity, which does not mean that the impacts were inconsequential. It means they were microscopic.

We learned this year, for instance, that exercise changes how our cells communicate with one another, as well as how rapidly they age. This new research began to detail the many, pervasive ways in which working out alters the inner workings of our bodies and contributes to better health.

When the scientists subsequently isolated these vesicles in mice and tagged them with a dye that glows, they tracked where they went and discovered that most homed in on the liver. There, the vesicles entered the organ, dissolved and delivered a load of biological stuff, including snippets of genetic material that can supply messages to other genetic material.

In this way, the scientists speculate, the vesicles probably delivered a biological alert to the liver, letting it know that exercise was underway, and it might want to start releasing stored energy for use by other, working tissues, like the muscles.

This study is a bracing reminder that multiple far-flung bodily systems are involved when we move and they all must communicate, but the process is bogglingly complex and, for the most part, still to be mapped.

It found that sedentary, middle-aged people who took up aerobic exercise for six months developed longer telomeres in their white blood cells. Telomeres are the tiny caps on the ends of chromosomes that protect our DNA from damage during cell division. Telomeres shorten as cell ages, until they are so abbreviated that the cell cannot function and often dies. Lengthy telomeres, on the other hand, are thought to denote relative cell youth and vigor.

In this study, aerobic exercise appears to have lengthened people’s telomeres, almost dialing back time.

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