Bone is just like muscle: If you don’t use it, you lose it. Granted, the best time to build bone has unfortunately passed. “We gain about 40% of our total bone mass during a four-year period of adolescence,” says Karen Troy, PhD, associate professor of biomedical engineering at Worcester Polytechnic Institute. However, even though we reach peak bone mass around age 20, “we still have the capacity to gain bone up to about age 50,” Troy adds.
One important way to increase bone mass — and preserve it in our 50s and beyond — is through exercise. “Bone is not static,” Troy explains. “It adapts to the different types of mechanical forces that it experiences on a daily basis. When cells inside the bones sense these forces, they send biochemical signals to other cells that either add or remove cells where needed.” In turn, our bones become stronger.
STRONG MUSCLES AND STRONG BONES
One of the best ways to elicit these bone-building signals is through weight-bearing exercises. In these movements, gravity is the mechanical force your body and bones work against. Exercises such as running, jumping rope, plyometrics and strength training are all weight-bearing and shown to improve bone health in adults.
“Muscle health and bone health are closely linked in two ways,” Troy says. “One, people with strong muscles will generate more forces on their bones because the muscles are able to compress the bones. Second, there’s a biological link. Cells in the muscles that wrap around the bones talk to cells on the surface of the bones. So anytime you do something that will help your muscles, you’re probably also doing something that will help your bones.”
And yes, that includes high-impact exercises. Although many of us think these are “bad” for our joints, “our bone cells like it when forces are applied very quickly,” Troy explains. So if your knees don’t bother you, make sure you’re doing some running or jumping exercises. And if you do have joint pain, modify these exercises to your comfort level so you get the benefit without aggravating your knees. You might not jump as high or hold onto a chair while jumping. A personal trainer can also help modify exercises and develop a progressive program. In a small study of postmenopausal women with mild knee osteoarthritis, a progressive high-impact training protocol improved patellar cartilage quality without causing pain.
ADAPTING LOW-IMPACT EXERCISES
Although yoga is technically weight-bearing, it’s usually too slow to have bone benefits, Troy says. Similarly, walking is weight-bearing, good for our bones, has cardiovascular benefits, helps keep muscles strong, and helps reduce the risk of falls. However, “it’s unlikely that walking by itself will cause you to gain any bone,” Troy says. “You will need to do more to maintain bone mass.”
If you enjoy these activities or non-weight-bearing ones like swimming and cycling, add some strength training. Just one or two sessions a week is enough to help, Troy says. For the most benefit, do exercises with some type of resistance, such as weights or resistance bands, or add a jump to movements like squats. Even light weights may increase bone mineral density when you perform a high number of reps, according to a 2017 study published in The Journal of Sports Medicine and Physical Fitness.
Lastly, if you want to maintain or build bone, you can’t ignore other factors. Smoking and excessive alcohol increase the risk of osteoporosis, If you need help quitting or reducing your intake, talk to your doctor or seek a support group. Diet is also important. Oxidative stress from free radicals can cause bone loss, but studies show eating a diet rich in various antioxidants (found in colorful plant foods) may support bone health. Be mindful of your calcium and vitamin D intake. (Talk to your doctor or a registered dietitian about supplements if you are concerned.)
Check out “Workout Routines” in the MyFitnessPal app to discover and log workouts or build your own with exercises that fit your goals.