Time to train: Keeping fit involves much more than cardiovascular workouts

Everyone knows that exercise is one of the best things you can do for your health. But most people ignore one crucial component of it: resistance training. According to federal researchers, only 6 per cent of adults do the recommended minimum amount of at least two muscle-strengthening workouts each week. Neglecting resistance training — any type of workout that builds strength and muscle — is a big mistake. It increases your metabolism, lowers your body fat and protects you from some of the leading causes of early death and disability. You don’t have to lift like a bodybuilder (or look like one) to benefit from resistance training. And it’s never too late to get started. Here is what you need to know about resistance training, along with some simple, expert-approved workouts you can do at the gym or at home with minimal equipment.

Fighting back against muscle loss

Our muscles are invaluable. They’re the reason we can walk, run, climb and carry things around. But as we get older, they begin to melt away. Muscle starts to deteriorate when we reach our 30s. After age 40, we lose on average eight per cent of our muscle mass every decade, and this phenomenon continues to accelerate at an even faster rate after age 60. Studies show that this loss of muscle hastens the onset of diseases, limits mobility, and is linked to premature death.

Another detrimental consequence is the impact that this has on your bones. The same factors that help you maintain muscle are the same factors that keep your bones strong and dense. So as you lose muscle with age — a process called sarcopenia — your bones become brittle, a process known as osteopenia, said Wayne Westcott, a professor of exercise science at Quincy College in Massachusetts.

“The bones, muscles, ligaments and tendons in your musculoskeletal system all work together, and they either become stronger together or weaker together,” he said. “Whenever you lose muscle you automatically lose bone — they go hand in hand.”

Because your muscles and bones are inextricably linked, when you lose muscle you’re at greater risk of osteoporosis, arthritis, chronic back pain, frailty and fractures.

Most people accept the loss of muscle, bone and all the downsides that follow as a natural part of aging. But studies show you can slow and delay these processes by years or even decades with a muscle strengthening program that works your entire body. Scientists at the Buck Institute for Research on Aging found that doing just two resistance-training sessions each week can reverse the age-related cellular damage that contributes to sarcopenia and functional impairment.

“Resistance training is the closest thing to the fountain of youth that we have,” said Brad Schoenfeld, an assistant professor of exercise science and director of the Human Performance Laboratory at Lehman College in New York.

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Build muscle, live longer

In 2014, researchers at the University of California, Los Angeles medical school discovered something striking.

They followed about 4,000 healthy adults over the age of 55 for more than a decade and noticed that their muscle mass was tightly linked to their lifespans. The researchers did this by zeroing in on each person’s “muscle index” — your muscle mass divided by your height squared. Those who were in the group with the highest muscle index had the lowest mortality, while those who had the lowest muscle index had the highest mortality rates. This relationship remained after the scientists accounted for traditional markers of disease, and it showed that muscle index was an even better predictor of premature mortality than obesity.

Another study recruited over 2,200 middle-aged men and followed them for up to 44 years. The researchers found that being physically active and having “good muscle strength” in middle age were among the strongest predictors of a longer lifespan. Over the years, a number of other studies have also shed light on why resistance training can be so beneficial.

• It improves cardiovascular health. Resistance training increases blood flow to muscles throughout your body, which lowers your blood pressure.

• Resistance training significantly improves your VO2max and your overall cardiorespiratory fitness. Studies have linked this to better heart health and a lower risk of death from cancer.

• Skeletal muscle helps regulate and dispose of blood sugar. Muscle soaks up glucose like a sponge, using it for energy or storing it as glycogen for later use.

• Resistance training makes you insulin sensitive. To absorb glucose from your bloodstream, your muscle cells must be responsive to the hormone insulin, which pushes blood sugar into cells. Studies suggest that an early step in the development of Type 2 diabetes occurs when your muscles become insulin resistant. Resistance training accomplishes the opposite: it makes your muscles insulin sensitive.

• Muscle acts like a coat of armour against diabetes. A 2011 study in the Journal of Endocrinology & Metabolism found that for every 10 per cent increase in your skeletal muscle index, you see an 11 per cent reduction in your risk of insulin resistance and a 10 per cent reduction in your risk of pre-diabetes.

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Keep it consistent 

One of the worst parts about losing muscle as we age is that we also get fatter. The average person gains about a pound of fat a year in middle age. That means that our bodies undergo a striking change in composition, with muscle melting away and fat creeping in to take its place. This reshaping of the body reduces your metabolic rate because muscle is more metabolically active than fat — causing things to get worse. 

But a recent landmark study provided some reassuring news. It looked at the effects of diet and exercise programs on 250 people over the age of 60 to compare how the programs affected their fat and muscle composition. The subjects were split into three groups. One was assigned to follow a program that cut about 300 calories a day from their diets. Another group cut calories and did about 45 minutes of aerobic exercise four times a week. And a third group cut calories while embarking on a resistance-training programme.

The results were striking. The subjects that combined both diet and exercise lost the most amount of weight, roughly 20 pounds on average. But here’s where it got really interesting. The group that did aerobic exercise lost 16 pounds of fat and four pounds of muscle — while the group that did resistance training lost more fat (18 pounds) and less muscle (only two pounds). Other studies have had similar results, confirming that one of the best ways to burn fat and hold onto muscle is to combine diet with resistance training.

© 2018 The New York Times