Sunday, December 31, 2006

Losing It: The Difficulty Building and Keeping Muscle as We Age

The process of losing muscle has a name, it’s called sarcopenia. For most of us loss of muscle due to aging starts around our mid-forties but for an unfortunate few it can start as early as twenty five. In the past few years sarcopenia has received more attention by the medical community because of the number of HIV patients who suffer from it. Several studies and programs looking at the effects of hormone-replacement therapy, and the development of drugs to directly target the biochemical causes of sarcopenia, are in progress such as those sponsored by the U.S. National Center for Research Resources (NCRR Reporter, Summer 2000, Muscle Building). But until the time comes when alternative treatments are available we’re on our own.

By fifty the average person will have lost 10% of his or her muscle mass along with a corresponding decrease in strength, and by seventy this loss will have risen to 40%. The resulting decline in strength is the primary cause of the high incidence of accidental falls seen among the elderly. It also contributes to our institutionalization when motor skills become insufficient to deal with normal day-to-day living requirements. Furthermore sarcopenia is linked to increased tendencies towards obesity, glucose intolerance, osteoporosis, and the inability to regulate body temperature; all effects of having less muscle – the body’s most metabolically active tissue – present.

There are likely several factors contributing to sarcopenia: loss of nerve cells from aging or HIV causing the associated muscle cells to be lost as well, diminished hormone levels, an impaired immune system, or diets with insufficient protein, all inhibit muscle growth and contribute to its loss. But by consensus the primary cause of muscle loss is simply not using them. The old saying “if you don’t use it you lose it” applies here in spades. Even more alarming for women studies have shown there's a strong
correlation between sarcopenia and those who have lower levels of musculature to begin with. So the trick is to ‘bank’ some muscle when young and then maintain it by regular exercise as you grow older. Study after study has shown physical activity, with weight training of sufficient intensity being cited as particularly effective regardless of one’s age, is the key to reducing the rate of inevitable muscle loss as we grow older.

For me this subject is very relevant. Always skinny as a boy I gradually built up my body until by my early thirties I topped out at around 88 kilos or about 195 lbs. For me it was how my body moved and handled physical challenges which justified the extra work in its maintenance, though it clearly paid for itself in my social life. By my early forties, however, work and a decreased emphasis on dating resulted in my paying less attention to my training. Then my recent back problems. When I finally got back on track and recommenced regular exercise I was shocked to discover in five or six short years I’d lost all the extra musculature I had built up over the prior fifteen plus. I was right back at square one at the age of forty six. It is not a good feeling. In one of my life’s great ironies I’m back in the same sport where as a child I told myself, “wait until I get some muscle” and find myself nearly four decades later still saying the very same thing. Life, unfortunately, sometimes does come full circle.


Isis said...

Thanks for this important reminder. I say reminder because I knew this, but had chosen to ignore weight-training and strength-training for the last 5 months. Your post helps motivate me to get back on the wagon!

Happy new year, by the way.

Scott said...

If you need any more motivation my companion piece this month on osteoporosis will provide a big boost. And happy New Year to you too!

Isis said...

Ugh. Nothing says Happy New Year like osteoporosis.