It seems that most of us are aware that women begin to lose bone at a more rapid rate after menopause. We're pretty well-schooled in the fact that we need about 1200mg of calcium (1500 mg if not on hormone therapy), 600 mg of magnesium and at least 1000 IU of vitamin D3 daily in order to help our bodies continue to build bone and prevent osteoporosis. And we've been told to do weight-bearing exercises to protect our bones. What seems to be missing for many is a clear understanding about the exercising and, therefore, less than enthusiastic motivation to not only start it, but to stick with a program as routinely as we brush our teeth.
So here's the scoop. The natural process is for bones to break down and rebuild themselves on a daily basis. This is a life-long process though the rates change. Until about age 30, bone build-up outpaces bone breakdown. After the peak of bone mass is reached about age 29, loss begins to accelerate. This is especially true in peri menopause when our estrogen levels begin to decline. Estrogen is a key player in the cycle of bone life. Our minimal goal by our 30s then needs to be maintenance. Having established our peak mass, good nutrition, proper supplements and exercises will support this goal.
Where the exercise enters the equation is with the fact that bones are slowly shaped by the forces that they withstand, for example each time your foot strikes the ground or your arm swings a tennis club and hits a ball. This occurs gradually and must be continuously attended to. It's a simple fact really: women who are more active throughout life have stronger bones than those with a more sedentary lifestyle. The way that weight-bearing exercise works is that this specific type (running, brisk walking, step or water aerobics, dancing, weight training...) stimulates the growth of new bone. Each major muscle in our bodies is anchored to underlying bone by tendons. Each muscle contraction exerts force on that bone, so any exercise that uses muscles puts stress on bone and helps increase bone mass. Succinctly stated, every time a muscle pulls on a bone, the bone cells that promote growth are stimulated and the result is stronger, denser bones. A meta-analysis of research found that women who exercise increased the density of their spines by ~2%. For those women who took hormone therapy, strength training had additional benefit to their bones over hormones alone.
"Regardless of your diet, supplements or any drugs you may be on, the big news is that weight-bearing exercise in general and strength training in particular play a crucial role in creating and maintaining healthy bones." Northrup, C. The Wisdom of Menopause (2006). p 418. NY: Bantam Books. The key isn't necessarily what exercise you choose, it's that you choose one -or some- and keep on toward the very achievable goal of stronger bones.
Osteoporosis is the most common bone disorder affecting humans, and it is completely preventable. If you, like me, have not managed to avoid some bone loss with aging, the great news is that it is reversible. It is never too late to start. You can build up strong bones.
Published On: March 20, 2009