BY EVA NORLYK-HERRIOTT
For most of us, getting older is associated with graying hair, sagging and folds in the oddest places, and wrinkles that drop in like unwelcome visitors and somehow never leave.
The most profound shift of aging, however, creeps up on us over the years, unseen and unnoticed. Like the proverbial flapping of a butterfly’s wing, it starts with small, innocuous changes, which over time produce large-scale effects, creating a tidal wave of systemic transformation. This invisible decline is the slow, progressive loss of muscle mass and strength that starts as early as age 25. In the medical literature, this phenomenon is known as “sarcopenia.”
Loss of Muscle Mass
Progressing slowly at first, sarcopenia becomes a real concern from the mid-40s and onward, as the muscle loss continues to accelerate, progressing at an estimated rate of 1 percent per year. By the age of 70, the average person has lost about 25 percent of muscle mass; another 25 percent, on average, is lost by the age of 90.
Sarcopenia is not a disease—it comes with no high-tech tests or fancy drugs, and it has received relatively little attention in our market-driven medical system. That doesn’t mean that it is not significant, however. Sarcopenia is the backdrop against which a multitude of age-related changes and ailments arise. Ever wonder why you eat like a bird and still gain weight? If you are above 45, sarcopenia may well be a factor.
Muscle tissue is the most active metabolic tissue in the body, and when muscle mass decreases, so does the resting metabolic rate of the body. With loss of muscle mass, we need fewer calories. Yet when we continue to eat the same amounts, the result, inevitably, is those extra pounds.
Sarcopenia is also a factor in the development of osteoporosis and in diminished cardiovascular fitness. It is thought to play a role in impaired glucose tolerance, diabetes, arthritis, and immune dysfunction. In addition, sarcopenia impacts our ability to withstand disease, because when we’re sick, the body draws protein from the muscles to fight illness and heal wounds. If the muscle protein “reservoir” is depleted by sarcopenia, resistance is less.
Most significantly, sarcopenia leads to what for most people is the leading concern of aging—the progressive frailty that prevents the elderly from living a full and independent life. The frailty that stems from loss of muscle mass is even more universal than the disability associated with osteoporosis. Sarcopenia is a serious degenerative condition. It appears as innocuous changes at first—difficulty climbing the stairs, getting up when we kneel down, and so on. But over time, these small shifts make it harder and harder to perform even simple daily activities. And of course, the harder it is to bend down and reach for that pan at the bottom shelf in the cabinet, the less we do it, creating a vicious cycle of gradually decreasing physical activity, which speeds up muscle loss even more.
Statistically, women—who have less muscle mass than men to begin with—face higher risks from loss of muscle mass.
Sarcopenia is caused by several factors. As we age, the nerve cells that link the brain to the muscles gradually die off. As the chemical connections to the muscle cells are lost, the cells begin to deteriorate. Hormonal changes play a role as well. The levels of testosterone, estrogen, and growth hormone decline with age. These hormones are involved in protein metabolism and maintenance, and as the rate of muscle protein synthesis declines, muscle mass decreases, and further, the muscles are less able to regenerate themselves following injury or overload. Inadequate protein intake can also play a role. If we don’t get enough protein, the body will use amino acids from the muscles as an extra source of protein.
Use It—Don’t Lose It
The largest predictor of sarcopenia, however, is lack of physical activity. When it comes to muscles and aging, “use it or lose it” pretty much sums it up. Physical inactivity precipitates a faster and greater loss of muscle mass.
Fortunately, loss of muscle mass can be slowed and, to a degree, reversed. Building muscle mass, particularly after the age of 45, is like putting savings in the bank. All other things equal, it will help see you through old age with much greater vitality, energy, and health.
Pushing Back Sarcopenia
Popular fitness activities such as walking, jogging, swimming, and biking provide great aerobic exercise for strengthening the heart and lungs. These are endurance-related activities, and they mainly increase a certain type of muscle fiber, the so-called slow twitch muscle fibers.
You also need to include activities that strengthen the so-called fast twitch fibers of the muscles, which tend to be lost in greater numbers. The fast twitch fibers are involved when a high, sudden muscular action has to be mobilized, e.g., to prevent a fall. You are engaging fast twitch fibers for such things as opening tightly sealed jars, carrying heavy groceries, or pulling deeply seated roots out of the ground.
The best way to strengthen your muscles is physical activity that involves weight bearing. The standard fitness prescription for sarcopenia is progressive resistance training. As little as two 40-minute sessions a week are enough to yield the results you need.
Keep in mind the need for variety, however. Muscle fibers develop according to how much they are used, so it’s important to have a well-rounded exercise program that mobilizes all the different types of muscle fibers. Many people find it rewarding to engage in activities that involve both weight bearing and coordination, such as yoga, tai chi, martial arts, and some forms of dance. These holistic forms of activity help keep the body vital because they augment multiple dimensions of fitness, like posture, flexibility, and endurance.
The good news is that a little goes a long way. Physical activity provides not just increased muscle strength, but also the increased energy that comes with being stronger. As you build muscle and physical fitness, you create a positive cycle—the better and stronger you feel, the more likely you are to stay active and do things you enjoy. And the more active you stay, the more likely you are to be able to continue to enjoy your life to its fullest, no matter what your age.
Eva Norlyk-Herriott, Ph.D., LMT, RYT-200, is a writer and bodyworker specializing in therapeutic yoga and massage. Reach her at (641) 470-2737 or Fairfieldyoga@yahoo.com