Everyone knows that muscle moves you — that each time you blink, take a step or cram your suitcase into an overhead bin, your muscles make it happen. But “what scientists are just now understanding,”…
Everyone knows that muscle moves you — that each time you blink, take a step or cram your suitcase into an overhead bin, your muscles make it happen. But “what scientists are just now understanding,” says Andy Galpin, director of the Biochemistry and Molecular Exercise Physiology Laboratory at California State University–Fullerton, “is just how synonymous muscle health is with all health.”
Recent research shows that the amount of muscle on your frame is a leading indicator of health and longevity, with one 2017 study finding that lean muscle mass outperforms body mass index, or BMI, at gauging overall health. What’s more, a 2015 study published in The Lancet suggests that grip strength — a widely recognized surrogate for total-body muscle strength and health — can more accurately predict our likelihood of death by heart disease than can blood pressure.
“We tend to compartmentalize the body as the muscular system and the skeletal system and the cardiovascular system and the nervous system and the immune system, but the body is one system,” Galpin says. “When one part gets healthier, everything gets healthier. And muscle is the one part over which you have the most direct control.”
Muscle, which comprises roughly 40 percent of the body, is a massive endocrine organ, communicating via hormones to the liver, heart, brain and other endocrine glands to influence metabolic, hormonal and cardiovascular health. “I love to tease endocrinologists and tell them that diabetes is not a disease of the pancreas; it’s a disease of the muscle,” says Tim Church, adjunct professor of preventive medicine at Pennington Biomedical Research Center at Louisiana State University. “The biggest consumer of blood sugar in your body is skeletal muscle, so when you think about insulin resistance [a chronic condition in which the body does not properly process blood sugar], you have to understand it’s happening at the muscle level.”
By building muscle through resistance training, you increase the amount of tissue available to use and store glucose for energy. You also improve the ability of specialized proteins to deliver glucose to that muscle, per one review by Austrian and Yale scientists. They found that this enhances the body’s ability to process glucose and to use fats and sugars for fuel, while combating abdominal fat and helping prevent or manage Type 2 diabetes.
That partly explains why, when Harvard T. H. Chan School of Public Health researchers followed 10,500 men over 12 years, they found that people who performed 20 minutes of resistance training per day gained less abdominal fat, a marker of overall health, than those who spent the same time frame doing cardio.
While aerobic exercise has long been prescribed to burn fat, current studies consistently demonstrate that resistance training, by building both the size and cellular health of muscle, leads to bigger reductions in body fat. After all, the biggest factor you can control when it comes to your basal metabolic rate — the number of calories your body burns each day to keep you alive — is your muscle mass, Church says. Evidence suggests that muscle tissue accounts for approximately 20 percent of total daily caloric expenditure.
However, researchers are learning that muscle doesn’t only process sugar and burn calories, it also builds. Muscle serves as the body’s predominant amino acid reserve, supplying the materials needed for the body to produce wound-healing molecules, antibodies and other proteins that are important for sustaining health.
That may in large part explain why people with more muscle live longer and are better able to combat disease, says Arny A. Ferrando, a professor of geriatrics with the Center for Translational Research in Aging and Longevity at the University of Arkansas for Medical Sciences. He explains that muscle mass is a strong predictor of disease survivability, including cancer treatment outcomes. Muscle wasting is a common complication of cancer treatment, and contributes to a higher risk of chemotherapy side effects and lower survival rates, research suggests.
“All of these fields are starting to turn their eyes heavily toward muscle and say, ‘OK, muscle is a major priority,’ ” Galpin says. “If muscle is out of whack, the rest of our treatments and interventions become secondary to affecting the muscle issue.”
Many of us don’t. Sarcopenia, or age-related muscle loss, typically sets in after our 30th birthday. From age 50 on, people naturally lose 1 to 2 percent of their lean leg mass annually, and 1 in 3 adults 60 and older suffers from severe muscle loss, research suggests.
Thanks to our culture’s embrace of sedentary lifestyles, muscle loss is becoming an increasing health threat, even showing up at ages when muscle mass should be peaking. Meanwhile, the muscle that’s left tends to be weaker. That’s because so-called fast-twitch muscle fibers, those that contribute most to strength and power, are the first to go in young adults who let inactivity and poor nutrition set in. The ones that remain, the slow-twitch fibers more responsible for endurance, are more resistant to aging until later decades, says Christopher Travers, an exercise physiologist with Cleveland Clinic Sports Health.
Fortunately, science has made it easier than ever to build the muscle you need for optimal health. Here’s your muscle health Rx:
Strength train at least twice a week. Current guidelines from the Centers for Disease Control and Prevention prescribe at least two days per week of muscle-strengthening activities. Galpin recommends gradually increasing that weekly goal to three to five days as your technique and strength levels improve.
Move through a full range of motion. When performing strength-training exercises, prioritize using resistance — think weights, bands or your own bodyweight — that you can control through a full range of motion. If you’re doing a squat, say, that means sinking as low as you can without compromising your form. Doing so trains more muscle fibers and improves joint range of motion, Galpin says.
Focus on compound exercises. “The body’s muscles are like a symphony,” says Jason Machowsky, an exercise physiologist and sports dietitian at the Hospital for Special Surgery in New York City. “There are different instruments at play, but it’s them coming together that creates effective motion.”
Compound movements, such as deadlifts, lunges, squats, presses and rows, achieve symphonic harmony by tapping multiple muscle groups and joints at once, while training the body to perform movements of everyday life. Bonus: Compound movements can burn more calories and build more muscle than can isolation exercises such as biceps curls.
When performing compound exercises, it’s also important to remember that your body is a 3D object and meant to move in all planes of motion, Machowsky says. In addition to performing front-to-back exercises such as lunges, bench presses and rows, integrate side-to-side exercises such as lateral band walks, side lunges and shoulder raises. Lastly, incorporate rotational movements such as woodchops and rotational presses. You’ll not only build more muscle, but also you’ll build functional muscle that’s prepared to support you through all of life’s movement patterns.
Load up. “One of the most common mistakes in resistance training is that the load, or weight moved, is too low,” says exercise physiologist Abbie E. Smith-Ryan, director of the Applied Physiology Laboratory at the University of North Carolina–Chapel Hill. Resist the temptation to go easy. To build muscle, a repetition range of eight to 12 is generally a good place to start, she says. “You should pick a load that you cannot do for more than 10 to 12 reps.”
Pump up the protein. Skimping on protein is a surefire way to undercut your muscle goals, says Machowsky, explaining that every bout of strength training creates microscopic damage to the body’s muscle cells. It’s only by providing them nutrients, including protein, that they are able to repair and grow back stronger.
Currently, the recommended daily allowance of protein, which represents the minimum nutritional requirement, is 0.8 daily grams of protein per kilogram body weight, or about 55 grams for a 150-pound person. However, the latest science suggests that adults need up to double that amount to achieve optimal muscle health.
“Given that protein’s amino acids are stored in the liver only temporarily, we have to pay attention to the timing if we are looking to maximize protein synthesis in the body,” says Kelly Pritchett, assistant professor of sports nutrition at Central Washington University and spokesperson for the Academy of Nutrition and Dietetics. A 2018 review published in the Journal of the International Society of Sports Nutrition suggests that, for the best results, people should consume 0.4 to 0.55 grams of protein per kilogram of body weight four times per day. For a 150-pound adult, the recommendation works out to four meals of 27 to 37.5 grams of protein each.
Ramp up your routine. As your muscles adapt to your workouts, it’s critical to systematically increase the demand placed on your body, Galpin says. Progressive overload, as it’s called, can be achieved by increasing exercise intensity, load lifted, number of reps and sets performed, or workout frequency. He recommends increasing how hard or much you work by no more than 5 to 10 percent per week to allow sufficient recovery.
Prioritize active recovery. The hours and days in between each workout are meant to help your body repair and rebuild your muscles, with a given muscle group needing roughly 36 to 48 hours to fully recover after a hard workout. “But recovery is not just about waiting, it’s about the things you do in that period to help your body recover,” Machowsky says. He recommends prioritizing good sleep, balanced nutrition and lower-effort movement. Research shows that low-intensity aerobic exercise such as cycling is an effective way to promote muscle strength and recovery after tough workouts.