How often do we hear that we should protect our bones in order to prevent osteoporosis? Health experts remind us to take calcium, do weight-bearing exercises to grow new bone, and maintain a healthy lifestyle including avoiding excess coffee, alcohol and cigarettes. But how many of us are familiar with the term sarcopenia, which is the devastating loss of muscle that can occur as we age? Strangely enough, health messages regarding this deterioration of muscle are not on the public's radar.
It has long been assumed that part of the natural aging process is to lose muscle, develop a stooped posture, and become less coordinated and less steady in our gait. For many years, scientists believed that nothing could be done to halt this deterioration of muscle as we age. Fortunately study after study has proven that this is an incorrect assumption. Health experts now know that sarcopenia is not inevitable.
While a decline in muscle is much more pronounced in the elderly, it is important to learn about it as early as possible because the process can begin as early as our mid 30s. By age 45, muscle mass begins to decline at a rate of 3-10% per decade. It doesn't sound like much at first, but by age 65 an individual can have as much as 1/3 less muscle than they had in their 30s. With a decline in strength comes a corresponding decline in physical ability and coordination -- to climb stairs, do chores, take walks or perform other physical activities. This can affect both men and women, but it is often more devastating in women because females generally have less muscle to begin with.
What causes this long, slow decline in muscle? To be sure, some of the causes such as disease, genetics or environmental conditions are beyond a person's control. But here are some major contributing factors that are within your control:
- Dietary deficiencies - As we age, many of us eat less. And in particular, we eat less protein which is the building block of muscles. A healthy, balanced diet which includes plenty of protein is important in maintaining muscle mass.
- Not enough muscle-stimulating exercise - It is important to do weight-bearing exercises such as weightlifting, calisthenics, yoga, and martial arts in order to prevent muscle deterioration and to add new muscle.
- Declining hormone levels - Hormones such as estrogen, testosterone and human growth hormone directly affect the amount of muscle we have. As hormone levels drop, our muscles can begin to atrophy. Fortunately, exercise itself can help boost these important hormones as we age.
- Loss of neuron cells in muscles - We lose motor nerve cells which send important messages to our muscles to keep them strong and growing. Again, exercise is the best antidote!
What are some of the implications of sarcopenia? For starters, loss of muscle mass results in a decrease in metabolism. Muscles are metabolically active powerhouses that burn a tremendous amount of calories for fuel. So the less muscle you have each year, the fewer calories you burn. This lowered metabolism means you must eat fewer calories just to maintain your weight. To complicate matters, it can be very difficult to detect early muscle loss. Many people rely on their bathroom scale to gauge whether or not they are holding their weight steady. But the bathroom scale only reveals part of the story. While a person may maintain the same weight for years or decades, it is likely that one's body composition (the amount of lean muscle vs. the amount of body fat) has actually changed over the years. With a small but steady decline in muscle each year, over time you can end up with a much higher percentage of body fat. This explains why your clothing may fit a little more snugly despite the scale remaining the same. It also explains why the same weight at age 50 looks nothing like it did at age 20! Fortunately, there are ways to measure our body composition so we can be sure we are not experiencing significant muscle loss. A bathroom scale which measures body fat in addition to weight can be a very useful tool. A simple tape measure can also reveal changes in body compostion. Or, you can visit a health club to have body fat tested with skinfold calipers or the very high-tech Bod Pod machine.
Sarcopenia can also contribute to osteoporosis, which is the loss of bone mass due to thinning and brittleness. Bones and muscles work in tandem to create a healthy physique. Strong muscles "tug" on bones creating tension, and this tension stimulates new bone growth. The absence of strong muscles can contribute to weakening bones. Also, a loss of muscle affects the entire musculoskeletal system and can lead to other problems with joints, tendons, and ligaments.
While muscle loss can occur in people of all fitness levels, physically inactive people will see a faster and greater loss of muscle than those who are physically fit. The expression "Use it or lose it" is completely applicable here. Muscle growth is stimulated through repeated use, and leading a sedentary lifestyle does not provide enough opportunity for the muscles to be challenged.
So, what is the best way to prevent sarcopenia? The answer is twofold: 1) Proper nutrition which includes sufficient calories, plenty of fruits and vegetables, and adequate protein levels, and 2) Exercise in the form of resistance training. We have already addressed some aspects of nutrition in previous healthy tips and will be revisiting this topic again and again. For now, eating a balanced diet which includes plenty of protein along with whole grains and fruits/vegetables, and eliminating heavily processed foods is a great first step.
Resistance training is any exercise that causes repeated contraction of a muscle group resulting in muscle growth and increased strength. It can include weightlifting with free weights or machines, calisthenics, yoga, pilates, martial arts, or exercises with rubber tubing and stability balls. Resistance training causes microscopic tears in the muscle fibers. The body is forced to repair these tiny tears in order to heal the damage and this results in muscle growth. A regular resistance training program performed 2-3 times per week for 20-30 minutes can significantly increase the amount of muscle mass an individual has. "Two months of resistance training can reverse two decades of typical muscle loss and three decades of typical muscle strength deterioration," says University of Maryland exercise physiologist Ben Hurley.
Many Americans choose cardio exercises such as walking, running, cycling or swimming as their preferred method of exercising. While these are terrific activities that improve cardiovascular fitness, they simply don't provide enough resistance to cause significant muscle growth. Sadly, muscle loss continues its steady march despite doing endurance exercises. A program that includes both cardio and resistance exercise is necessary for good health and strength.
Which muscles do YOU want?
In the coming weeks we will be incorporating resistance exercises into our overall wellness routine, so start looking for openings in your calendar where you can fit 2-3 sessions lasting 20-30 minutes each. Remember, developing a new habit is a skill that requires lots of practice. It won't get done if we don't make it a priority, so be sure to pencil-it in your calendar and get ready to watch your strength soar!
"Great ideas originate in the muscles."
~ Thomas Edison
Click here for more information on sarcopenia.
For an excellent beginners' guide to strength training, especially for older adults (from the Centers for Disease Control in collaboration with Tufts University) click here.