How Exercise Builds Stronger Bones at Every Age

The skeletal system holds everything up — literally. Beneath the surface, your bones quietly do the work of keeping you upright, protecting your organs, and facilitating movement. When that foundation weakens, the consequences can be far-reaching.

“If we don’t have a strong base with our bones, the other systems in our bodies are not going to function as well,” says Joseph R. Hribick, DPT, a certified orthopedic manual therapist and clinical assistant professor of physical therapy at Lebanon Valley College in Annville, Pa.

Yet more than half of U.S. adults over 50 have either low bone mass or osteoporosis, and many don’t realize it until they have a fracture. “That’s the sneaky thing: Bone loss happens gradually, and then all of a sudden someone has an incident and it’s a dramatic change in their lifestyle,” Hribick says.

Research consistently shows that low bone density is associated with a higher mortality risk, even after accounting for other health factors. And while declines in bone density are commonly linked to menopause, men are also vulnerable to bone loss and its associated risks. (By some estimates, about 20 percent of men over 50 will sustain an osteoporotic fracture at some point in their later years.)

“As bone density declines, you start seeing issues with balance and stability, which not only leads to a higher chance of falling but … affects someone’s confidence, so they’re less likely to move in certain ways or go out and participate in certain activities,” Hribick says.

Over time, inactivity erodes muscle mass and accelerates bone loss, creating a vicious cycle that can be difficult to break.

But the good news is that the cycle can be broken, and exercise is one of the most effective ways to do it. Weight-bearing and resistance exercises stress the skeleton, signaling the body to build and maintain strong bones. It’s best to start early, but it’s never too late to make a difference.

A Framework in Flux

The human skeleton is made up of more than 200 bones — specialized connective tissues composed of protein, collagen, and minerals like calcium and phosphorus. Each bone has a hard outer shell that provides structure and strength and a spongy center that produces blood cells and absorbs the impact of external forces.

But bones do more than hold us together.

“The skeleton helps us stand upright, walk, and do everything we need to do on a daily basis, like ­getting down to tie our shoes or opening a door,” says Sandra Tadros Guirguis, a Life Time group fitness ­instructor and Menopause ­Society–certified practitioner based in ­Toronto. Movement happens when our muscles, which attach to bones, pull on the bones like levers.

Bones also act as a protective shell for vital organs: The skull protects the brain, the rib cage protects the heart and lungs, and the spine protects the spinal cord.

And though they may seem like a rigid, static framework, our bones are in a constant state of renewal. “Bone is living tissue,” Hribick says. “It’s not something that we’re born with that’s then stagnant over the course of our life. It’s constantly degrading and rebuilding.”

Bone remodeling, or the continual process of bone formation and breakdown, is a tug of war between two types of cells: osteoblasts, which build new bone, and osteoclasts, which break down old or damaged bone.

“When things are going well, bone remodeling is a continuous, balanced process where osteoclasts remove old bone and osteoblasts replace it with new bone,” Guirguis says.

However, the bone-remodeling process doesn’t stay balanced forever. In our early years, our osteoblasts naturally outpace our osteoclasts, helping us build the skeletal frame­work we’ll carry into adulthood. By age 30, we’ve reached peak bone mass, and after that we have to work a bit harder to keep our bone-building cells ahead of the curve.

“You can still build bone den­sity — it’s just harder as you age,” Hribick notes.

To complicate matters, certain risk factors favor bone breakdown over bone formation and increase the risk of osteoporosis.

Nonmodifiable risk factors include having a smaller skeleton, having a family history of osteoporosis, and being female, Hribick says.

Age is another nonmodifiable risk factor. Despite its associations with older women, osteoporosis is also common in older men. (Learn more at “PUMPING IRONY: No Bones About It.”)

Meanwhile, modifiable risk factors include physical inactivity, low calcium or vitamin D intake, smoking, alcohol consumption, and corticosteroid medications. (Learn more at “How to Strengthen Your Bones.”)

Of all the modifiable risk factors, says Hribick, physical inactivity may be the most damaging yet the easiest to address.

How Exercise Builds Your Bone Bank

Exercise is akin to investing in your bones’ retirement account. “Invest as much as you can early in life so that you reap the benefits of it later,” Hribick says, noting that the prime years for building bone are between ages 8 and about 20.

However, even if you’ve long since passed that window, it’s never too late to start. Consistent exercise can shore up weak bones and maintain healthy ones, keeping osteoporosis at bay.

Some types of exercise are more effective at improving bone density than others. These include high-impact weight-bearing activities that trigger bone formation by exposing your bones to repeated mechanical stress.

“Ground reaction forces come up through your legs and into your spine, and then the weight of your body comes down with gravity,” Hribick explains. “So you have mechanical stress from below and mechanical stress from above, and that helps to stimulate these cells to lay down more bone.”

And the more impact an exercise delivers, the stronger the stimulus. “High-impact weight-bearing exercise — things like jumping, running, skipping, basketball, and volleyball — generates stronger bone-building signals at the cellular level,” Guirguis says.

But if you’re prone to fractures or are battling joint issues, the benefits of high-impact exercise won’t necessarily outweigh the risks. “For older adults, especially those with arthritis, I would not recommend high-impact activity,” Hribick says.

Adults should aim to stay active most days, working toward about 150 minutes of moderate-intensity activity weekly.

Luckily, high-impact exercise isn’t the only way to stimulate bone growth. Resistance training is another powerful ally.

“When we contract the muscle, we actually pull on the bone, and that in itself promotes bone production,” Hribick says.

Research backs this up. A 2025 meta-analysis in the Journal of Orthopaedic Surgery and Research found that resistance training ­significantly improves bone-­mineral density in the spine, neck, and hips of postmeno­pausal ­women.

In general, adults should aim to stay active most days, working toward about 150 minutes of moderate-intensity activity weekly, Guirguis says.

It’s not just about the total time: Variety matters, too. At least two days per week, focus on resistance training and balance exercises to help maintain bone strength and reduce the risk of falls and fractures.