Exercise and Your Bones
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Weight bearing and muscle-strengthening exercise helps you maintain and even increase bone density. But how? And why don't other kinds of exercise help your bones? Following are some answers for you. Do note that this matter affects and applies to both men and women! |
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Stress felt by the bones during exercise stimulates your bone-building cells to both maintain and make new bone. Weight-bearing exercise primarily helps you maintain bone mass as you age. To qualify as "weight-bearing", the legs must bear your weight -- as in walking, running, tennis and aerobics. Swimming, while a great aerobic exercise, is not considered weight-bearing. If walking is your choice, make sure you walk with enough intensity to "stress" your bones. This means moving briskly and/or taking on some hills. |
Muscle-strengthening exercise (e.g. weight-lifting) can actually help build bones. The chronic force of muscles pulling against bone stimulates the creation of new bone. See: Exercise!
A sedentary lifestyle can be a "bone density disaster". Take astronauts, for example. While living in weightless conditions, they drop about 1-percent of bone mass a week.
Important notes:
The benefits of weight-bearing exercise are site-specific. This means that you strengthen only the bones used directly in the exercise. Therefore, it's a good idea to participate in a variety of weight-bearing exercises. To maintain the bone-building benefits, exercise should be continued on a regular basis.
Weight-bearing activities at any age benefit bone health. Studies link physical activity with increased bone strength in children, teens, men and women, and even adults 90 years of age and older.
Too much exercise decreases hormones that are needed for good bone health. If a woman exercises to the point where she stops menstruating, she may actually increase her risk of the bone-crippling disease osteoporosis.
Weight-bearing exercise alone is not enough to protect you from osteoporosis. Even if you do weight-bearing exercise regularly, failing to eat enough calcium-rich foods will weaken your bones.
Vitamin K and Your Bones
Researchers suspect that green leafy vegetables also protect bone because they're loaded with Vitamin K. Vitamin K is best known for its ability to help blood clot, but a growing body of evidence suggests that it does much more. Vitamin K is important for proper functioning of bone-dependent proteins. Bone is constantly breaking down and rebuilding, and it needs those proteins to rebuild.
When Tufts researchers looked at nearly 900 men and women in a Framingham Heart Study, those who consumed roughly 250 micrograms of vitamin K a day (largely from food) had a 65 percent lower risk of hip fractures than those who averaged around 55 micrograms a day.
The question is whether it's vitamin K, something else in leafy greens, or something else about people who eat leafy greens that protects their bones. Until on-going research is conclusive, you can easily get enough vitamin K from greens. You can get 500 micrograms in just half a cup of cooked collards. And even if the vitamin K in greens doesn't make your bones more dense, it may still strengthen your skeleton.
See also: Exercise
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