Why Strength Training Is One of the Best Investments You Can Make in Your Bones

Justin English, MS, CSCS

When most people think about strength training, they think about building muscle.

What many don't realize is that one of the most important adaptations happens beneath the muscle itself.

Your bones are constantly changing and need work too.

Throughout your life, old bone tissue is broken down and replaced with new bone in a process known as bone remodeling. During childhood and early adulthood, the body builds bone faster than it breaks it down, allowing us to reach peak bone mass sometime between our late twenties and early thirties. After that, the balance gradually shifts. Bone is removed faster than it is replaced, leading to a slow decline in bone mineral density (BMD).

While this is a normal part of aging, it is not something we are powerless against.

Research consistently shows that appropriately prescribed resistance training is one of the most effective non-pharmacological strategies for maintaining—and in many cases improving—bone mineral density throughout adulthood.

Why Bone Density Declines

Bone is living tissue. Just like muscle, it responds to the demands placed upon it. If the skeleton is exposed to regular mechanical loading, it receives signals to remain strong. If loading decreases over time, the body has less reason to maintain dense, resilient bone.

Several factors contribute to declining bone mineral density as we age, including hormonal changes, reduced physical activity, lower muscle mass, inadequate nutrition, and decreased exposure to high mechanical forces. This process accelerates in postmenopausal women due to reductions in estrogen, but men also experience gradual bone loss throughout adulthood.

The concern isn't simply weaker bones. Lower bone mineral density increases the likelihood of fractures, reduces confidence in movement, and contributes to the development of osteoporosis—a condition affecting millions of adults worldwide.

Why Strength Training Works

Bones adapt according to a principle known as Wolff's Law, which states that bone remodels itself in response to the mechanical stresses placed upon it. Every time you squat, deadlift, press, carry, or jump, your muscles pull on the skeleton. These forces create microscopic strain within the bone, stimulating specialized bone-forming cells called osteoblasts to lay down new mineralized tissue. Over time, this process helps maintain or improve bone density.

Not all exercise provides the same stimulus. Walking, cycling, and swimming offer tremendous cardiovascular benefits, but they create relatively low mechanical loading compared with progressive resistance training and impact-based exercise. Research consistently demonstrates that moderate-to-heavy strength training, combined with weight-bearing activities such as jumping or plyometrics when appropriate, produces the greatest improvements in bone health.

A large systematic review and meta-analysis found that resistance training significantly improves bone mineral density in older adults, supporting its role as a cornerstone strategy for preventing osteoporosis and maintaining skeletal health.

The takeaway is simple:

Your bones adapt to the loads you ask them to handle.

If you stop challenging them, they gradually become less prepared to handle life's demands.

Why Measuring Bone Density Matters

If you've been strength training for years, how do you know whether your bones are actually getting stronger? The answer is simple: Measure them.

Dual-energy X-ray absorptiometry, better known as a DEXA scan, is considered the gold standard for assessing bone mineral density. Unlike estimates or screening questionnaires, a DEXA scan provides an objective measurement of bone health at clinically important sites such as the hips and lumbar spine.

The scan is painless, non-invasive, and uses very low levels of radiation. Within minutes, it provides highly accurate information about your current bone density and your relative risk for osteopenia or osteoporosis. For many people, a DEXA scan serves as a valuable baseline. Future scans can then determine whether nutrition, strength training, and lifestyle changes are producing meaningful improvements over time. Rather than guessing, you can measure.

At Unbroken Health & Fitness, We Believe in Measuring What Matters

Exercise should be intentional.

Training should be individualized.

Progress should be measurable.

Whether the goal is building strength, improving athletic performance, increasing longevity, or protecting bone health, objective data allows us to make better decisions.

That's why I'm excited to announce that Unbroken Health & Fitness will soon be partnering with a local clinic to provide DEXA scans for our clients. Along with assessments such as VO₂ max testing and movement evaluations, DEXA scanning will allow us to better understand how your training is influencing not just your muscles, but your long-term skeletal health.

The goal isn't simply to exercise.

The goal is to build a body that remains strong, resilient, and capable for decades to come.

Because strength isn't just about what you can lift today.

It's about protecting the foundation that carries you through the rest of your life.

References

American College of Sports Medicine. ACSM's Guidelines for Exercise Testing and Prescription. 11th ed. Wolters Kluwer, 2021.

Giangregorio, L., et al. "Too Fit To Fracture: Exercise Recommendations for Individuals with Osteoporosis or Osteoporotic Vertebral Fracture." Osteoporosis International. 2014;25(3):821–835.

Howe, T. E., et al. "Exercise for Preventing and Treating Osteoporosis in Postmenopausal Women." Cochrane Database of Systematic Reviews. 2011;(7):CD000333.

Kelley, G. A., Kelley, K. S., & Kohrt, W. M. "Exercise and Bone Mineral Density in Men: A Meta-Analysis of Randomized Controlled Trials." Bone. 2013;53(1):103–111.

Zhao, R., et al. "Effect of Resistance Training on Bone Mineral Density in Older Adults: A Systematic Review and Meta-Analysis." Journal of Bone and Mineral Metabolism. 2018. PMID: 28975661.

Dual-energy X-ray absorptiometry