The Secret to Aging: Use It or Lose It

    The Secret to Aging: Use It or Lose It



    Following is an excerpt from Bill Gifford’s wonderful book Spring Chicken: Stay Young Forever (or Die Trying). The book recounts the author’s adventures into the world of anti-aging research, which is populated by characters ranging from wanna-live-forever crackpots to serious scientists exploring the physical secrets of life. It’s entertaining, highly informative, and ultimately inspiring—for middle-aged athletes, or for anyone who suspects that health and fitness may not conquer death, but can help guarantee a vital life.

    While I was working on this book, nearly everyone I told about it wanted to know the same thing: “So, what’s the secret to aging?”

    So far, the “secret” seems to be: Use It or Lose It.

    Which sounds simple, even simplistic. But it kept coming up, almost like a mantra, not only in conversation but in high-level research: It applies to your cardiovascular system, your muscles, your sex life, and your brain. Howard Booth, a 70-year-old pole-vaulting biology professor whom I met at the National Senior Games,  had it all figured out.

    By contrast, not using it can have dire consequences. Even retiring from working—the capstone to the American Dream—can be dangerous to your health. A paper published by the National Bureau of Economic Research, a prestigious private think tank, found that “complete retirement leads to a 5–16 percent increase in difficulties associated with mobility and daily activities, a 5– 6 percent increase in illness conditions, and 6–9 percent decline in mental health,” over the next six years. Although early retirement has been found to decrease mortality risk, at least in Europe, newly retired people often report a loss of their sense of purpose— the Okinawans’ ikigai, again—which can be hard to replace.

    Physical parameters like strength and VO2 max tend to move in one direction with age: downward. But it’s not the same for everyone. A recent study of aged Scandinavian cross-country skiers found that the older athletes had preserved much of their aerobic capacity, relative to their youthful selves; and they were far ahead of the age-matched control group, a bunch of sedentary older guys who lived in Indiana.

    Which seems like the ultimate unfair comparison—Nordic ski gods versus Midwestern couch potatoes—but who would you rather be? The skiers had done a better job preserving their ability to pump blood efficiently, the elasticity of their arteries, the suppleness of their lungs. Biologically, they were simply younger. On a practical level, this meant that they had an easier time walking around, climbing stairs, and as Howard Booth put it, participating in life. They’d never stopped using it, so they didn’t lose it.

    If you look at older athletes’ muscles and bones, the contrast with their sedentary peers becomes even more dramatic. One of the hallmarks of middle age—and one of the first things I noticed—is that it becomes much more difficult to gain and keep muscle. We begin to lose muscle mass gradually at around age forty, and as time goes on we lose it more rapidly: Between fifty and seventy, we say good-bye to about 15 percent of our lean muscle per decade. After that, it jumps to 30 percent per decade. “You could make the case that aging starts in muscle,” says Nathan LeBrasseur, a researcher at the Mayo Clinic who studies muscle.

    But even as we’re losing muscle in middle age, we don’t lose weight overall (duh). That means our muscle is gradually, insidiously being replaced by fat. More fat and less muscle means your metabolic “engine” runs at a much slower rate; less muscle means you have fewer mitochondria, which means your body becomes less efficient at burning the sugar out of your bloodstream. Not coincidentally, most new cases of diabetes appear in people in their mid-forties and older. This loss of muscle may also be why our cholesterol levels tend to surge as we get older.

    Exercise not only preserves muscle mass, then, but it keeps our blood sugar and cholesterol levels under control—among myriad other benefits. “If you could put the benefits of exercise in a pill,” says Simon Melov, a researcher at the Buck Institute for Aging Research in Novato, CA, “it would be an astonishing pill.”

    Excerpted from Spring Chicken: Stay Young Forever (or Die Trying) by Bill GiffordCopyright © 2016 by Bill Gifford. Used with permission of Grand Central Publishing. All rights reserved.