After 16 weeks, the women following both the 10- and 20-jump programs saw improved hip-bone mineral density compared to the control group. "Physical activity, a modifiable risk factor [of osteoporosis], has been shown to provide a stimulus to bone that increases mineralization in areas of new stress," report the researchers. Impact exercises like jumping create this stress that encourages new bone formation.
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"People think of bone as dead, but bone is like coral in the sea; it's very much alive," explains Jordan Metzl, MD, author of The Exercise Cure. "Since bone is alive, it constantly throughout our lifetime can get harder or softer."
He explains that things that weaken bones include colored sodas, which leach the nutrients out of our bones, and, for women, going months without a period, which upsets estrogen bone metabolism. On the flip side, eating calcium- and vitamin D–rich foods, as well as performing weight-bearing exercise, can strengthen bones.
Dr. Metzl points out that jumping—and landing, in particular—is important for forming or strengthening bone. "The concept is something called Wolff's Law. Wolff's law is that that bone, given repetitive maximum rooting force will make more bone, or bone will get stronger." Put otherwise, a bone under force will adapt to that force by getting stronger, so impact activities like running, jumping, and dancing are bone protective.
Don't just make your muscles stronger with exercise; make your bones stronger, too, with these moves from Dr. Metzl.
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Plyometric Jump Squats
Place your fingers on the back of your head and pull your elbows back so that they're in line with your body. Squat until your thighs are parallel to the floor then explosively jump as high as you can (imagine you're pushing the floor away from you as you leap). When you land, immediately squat and jump again.
If the jump is too hard on your joints, skip the jump to do a standard body-weight squat. If it's still too hard, don't bend so deeply into the squat. To make the move more challenging, hold dumbells at your side.
Stand with your feet together and your hands at your sides. Simultaneously raise your arms above your head and jump up just enough to spread your feet out wide. Without pausing, quickly reverse the movement and repeat. (Here's more info on how to set up a zero-dollar home gym.)
Anything That'll "Jostle Your Bones"
As Dr. Metzl says, even simple moves like running in place or jumping rope can be a great way to put some healthy force on your bones. Plus, what better way to feel young again than to get out the old jump rope.
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