While stress may be bad for your heart, some form of it is actually great for your bones. We’ve all heard that weight-bearing exercise can strengthen bones, but what exactly does that mean? Lifting weights or pounding the pavement? Both, it turns out. Weight-bearing activities like running or brisk walking in which you bear the weight of your body as your feet hit the ground and gym workouts with dumbbells and machines, i.e. resistance training, help increase bone density, which is especially important as you age.

According to the National Osteoporosis Foundation, we reach our peak bone mass in our early 30s. What’s more, 1 in 2 women and 1 in 4 men over 50 have low bone mineral density (BMD), which makes them vulnerable to fractures. The goal once you’re past middle age is maintenance, says Catherine Jankowski, Associate Professor at the University of Colorado College of Nursing, who adds that it’s possible to restore lost bone mass. “Bones have a cycle called bone turnover, in which cells are continually breaking down and building up. We want to keep breakdown to a minimum and tip the scale toward building.”

To do that, we have to stimulate—actually stress—the bones to regenerate.  According to Alexander G. Robling, Assistant Professor of Anatomy and Cell Biology at Indiana University School of Medicine, the bone bends and releases fluids that signal cells to make more bone during weight-bearing exercises. The higher the impact, the more density is affected. “That means force into the ground,” says Jankowski. “Running at a fast speed, hopping off boxes, doing drop jumps from bench to floor.” The most effective workouts include stops and starts, sudden bursts of movement—as in tennis, say, or interval training that mixes sprints, burpees and jumping rope. Switching up the pattern of movement and type of muscle strain seems to stimulate bone building more than constant, repetitive motion. 

Though not as stressful to bones, low-impact workouts are still effective and a good option if joint trouble prevents running or jumping. Gravity is essential. Any exercise that pits body weight against gravity—push-ups, pull-ups, plies, lunges—can boost your BMD (and adding leg weights ups the beneficial stress). Take away gravity, and bones don’t get stimulated. No surprise, therefore, that swimming and cycling, while great for conditioning, don’t do squat for bones. If you’re looking to strengthen your bones, opt for a Zumba or kickboxing class instead of spin. The ever popular elliptical machine is considered a low-impact weight-bearing exercise as are the various types of barre classes.

Even yoga can strengthen bone. “Poses such as plank, bridge, downward dog and handstand require our muscles and bones to engage to support our weight,” says Laurel Attanasio, who runs yoga workshops around the world. And when you shift all your weight onto one foot for a standing pose like tree, she adds, you’re doubling the body weight on that side.

Then there’s resistance training with free weights and machines. As Jankowski explains, the pull of muscle against bone—as in bench pressing, or bicep curls—stimulates the bone. Not only does weight training tone muscles, there’s evidence that building muscle mass can increase bone mass. A study at McMaster University in Ontario found that after a year of strength training, post-menopausal women augmented their muscle size by 20 percent and their spinal bone mass rose by nine percent.  

Even if you don’t make it to the gym or a class, work a bit of bone-bashing into your day. Take the stairs instead of the elevator, get up from your desk and do some jumping jacks. Here’s some inspiration: A study out of Japan showed that rats who jumped up and down just five times a day for eight weeks increased their bone density significantly. If they can do it, so can you. 

 

Sources:

  1. National Osteoporosis Foundation
  2. McMaster University
  3. Journal of Bone and Mineral Research: Five Jumps per Day Increase Bone Mass and Breaking Force in Rats