It was one of those butterfly wing events: a butterfly flaps its wings and an earthquake erupts on the other side of the world. Well, in this case it was far less dramatic--my husband took a trip to Walmart in a last-ditch effort to put a few more Christmas presents under the tree, and I resolved a conundrum that had baffled me for more than a year. The mystery was this:
Why the heck was I getting fatter, even as my weight stayed the same?
For the last six months, my clothes had gotten tighter. This one particular pair of summer pants, which I use as a baseline for ideal trimness, on a recent trip to Florida had revealed itself to be, well, embarrassingly tight. Yet, I hadn't changed my eating habits one bit, and the scale kept reassuring me that my weight was the same as it had been for--well, I can't tell you how many decades, because that would seriously date me, but let's just say, my weight was pretty much the same number as it had been since my twenties.
That's what is soooo annoying about the midlife bulge. It creeps up on you, unannounced, unexpectedly, and inexplicably. I've seen it happen to friends for years--even people who have been skinny all their lives, suddenly begin to bulge, then inflate, then spread out, seemingly with no end in sight.
The problem with these kind of strange changes in your body is this: once started, where is it ever going to end? A few years down the road, would that innocuous bulge factor turn me into a full-fledged blimp? Scary thought, but we've all seen it happen.
So, back to Santa's Walmart adventure. A particularly unwieldy and heavy package under the tree turned out to be--of all things--a kettle bell with a brief instructional DVD.
Okay, some background is needed here. I've been an avid yoga practitioner for years. In addition to being a writer, I teach yoga, and I use yoga as therapy with my clients. I love yoga for its amazing effects on mind and body; and I have always shunned exercise forms that disassociate the mind from the body. You know, the kind where you park your mind in front of the TV while your arms mindlessly pump iron or your legs wander off to do 5K on the treadmill? Volumes could be written about how sad it is to disassociate mind and body during exercise, and the wonderful gifts one misses out on--of mental and physical development, and even spiritual deepening.
But I digress. My main point is this--I had avoided weight training like the plaque. Booooring! Mechanical and mindless! A waste of time! No matter that thumbing my nose at weight lifting as a fitness form was entirely yogic. I, for one, wasn't going to build a body of comatose bulk.
However, that stocky kettle bell in the midst of the crinkled Christmas wrapping looked strangely intriguing. Why not give it a try? So, next morning, I launched right into a couple of the workouts, heedlessly disregarding the warm-up section. Needless to say, I could barely walk or sit down the next few days. Still, I was hooked. This was surprisingly fun.
I read somewhere that high-intensity strength training produces human growth hormone. And indeed, there was a palpable change in the hormonal cocktail pulsing through my veins after each workout--creating the same feeling of youthfulness, aliveness, vibrancy I used to have as a kid. Sort of like spring--but in January.
So, I decided to let go of my very unyogic close-mindedness and added a kettle bell workout to my morning exercise routine 2 to 3 times a week. And this is when something really strange happened.
Within a very short while, my clothes began to fit again!
This was truly amazing. I finally realized why I had been getting fat, while not gaining weight. I had fallen victim to one of those scourges of middle age that slowly creeps up on us without our knowing: sarcopenia, or progressive muscle loss.
Despite a daily yoga practice, my writing work also forces me to sit much of the day. The upshot? Even though I was doing a moderate yoga practice, I was still losing more muscle mass than I was holding on to--or rather, as we shall see below, losing a particular type of muscle mass. Muscle mass is more dense than fat, so hence the strange phenomenon that even as my butt and waist line expanded as muscle cells slowly were replaced by fat cells, my weight stayed the same.
Sarcopenia--The Cousin of Osteoporosis
We hear a lot about the progressive bone loss of osteopenia and osteoporosis. The muscle equivalent of this is the progressive muscle loss a.k.a. sarcopenia, which begins to unfold as early as age 25. Progressing slowly at first, sarcopenia becomes a real concern from the mid-forties and onward, as the muscle loss continues to accelerate. From the mid-forties, most people lose muscle mass at an estimated rate of 1% per year! If you do the math, this means that by the age of 70, the average person has lost as much as 25% of their muscle mass; another 25%, on average, is lost by the age of 90--a staggering amount, which leads to numerous systemic changes in the body.
Sarcopenia is not a disease--it comes with no high-tech tests or fancy drugs, and as a consequence, it has received relatively little attention in our market-driven medical system. That doesn't mean that it's unimportant, however. Decreasing muscle mass is just as much a problem as thinning bones. Sarcopenia is linked to the thinning bones of osteoporosis, but it is also the backdrop against which a multitude of other 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 less 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 build antibodies, heal wounds, and fight illness. 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 makes it harder and harder to perform even simple daily activities--do chores, take a walk, climb stairs, go grocery shopping, and so on. 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. Women, who to begin with have less muscle mass by men, in particular face risks from loss of muscle mass. We, statistically, also are more likely to be too frail to take care of ourselves in old age.
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 muscles cells are lost, the muscle cells begin to deteriorate. Hormonal changes play a role as well. The levels of such hormones as 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.
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. And as we age, people with less muscle mass to begin with, like for osteoporosis, pay a higher price.
This was where the big surprise was for me. I had a daily, moderate exercise routine. But as the kettle bell taught me, because I also have a job that necessitates that I sit a good part of the day, it wasn't enough to slow the inexorable march of Father Time.
Half Empty or Half Full?
Fortunately, the glass is not just half empty, it is also half full. If you use it, you won't lose it. You can't completely halt loss of muscle mass as you age, but it 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.
The big lesson for me, however, was that it does matter which types of exercise you do, and cross-training is key. Popular fitness activities like yoga, walking, jogging, swimming, or biking are endurance-related activities. As such, 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 muscle fibers, which tend to be lost in greater numbers as we grow older. The fast twitch fibers are involved when a high, sudden muscular action has to be mobilized--such as, for example, in repeatedly swinging a kettle bell above your head.
The standard fitness prescription for sarcopenia is progressive resistance training, which uses muscles at a high level of intensity, i.e. close to their maximum contraction strength, for short periods of time. As little as two 40 minute sessions a week is 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. And, while it's important to train your muscles to become stronger, it's equally important to engage in forms of exercise, such as yoga, that challenges the mind and teach the muscles to work together in different ways, so that you build functional strength as well. As much as mere muscle mass, this will improve your performance in everyday activity.
Ultimately, many people find it most rewarding to engage in holistic physical activities that include both weight-bearing (using the body's own weight) and work all of the muscles in coordination, such as yoga, tai chi, martial arts, and some forms of dance. These holistic forms of activity help keep the body vital, energetic, and fully functional, because they augment multiple dimensions of fitness: not just muscle strength, but posture, flexibility, balance, and endurance.
The good news is that a little goes a long way, and carries its own rewards. Physical activity provides not just increased muscle strength, but also the vigor, increased energy and vitality that come 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--gardening, playing tennis, and the like, strengthening your body even more. And the stronger you become and more active you keep, the more likely you are to be able to continue to enjoy your life to its fullest, no matter what your age.
Wondering about the effects of yoga on osteoporosis? The jury is still out on that one, but for more information on that subject, see this interview with Dr. Loren Fishman and Ellen Saltonstall, authors of Yoga for Osteoporosis, about their ongoing study on the effects of yoga on osteoporosis.