Bones Get Bored: Why Running Isn’t Building the Strength You Think It Is

As a health professional working closely with runners, there’s one injury I really don’t like seeing: bone stress injuries.

Why? Because they often mean an extended break from running — the thing we love most — followed by an even longer process of gradually rebuilding fitness.

So, how can we reduce the risk? Like most injuries, bone stress injuries are multifactorial. Training load, running intensity, recovery (think sleep and stress), and nutrition all play important roles.

But here’s something that surprises many runners: Running isn’t actually a great exercise for building strong bones.

Sure, it’s weight-bearing — but that’s not the same as bone-building. Let’s explore why running falls short in this area, and what kinds of training do a better job of building more resilient bones.

Why Running Doesn’t Build Bones as Well as You Think

1. Bones Get Bored of Repetition

Running provides repetitive, low-to-moderate impacts in a single plane. While this is enough to maintain bone mass, it doesn’t create enough novel stimulus to drive further adaptation.

In fact, bone cells can become desensitised to continuous loading. After just 100 loading cycles, bone cells may lose up to 95% of their mechanosensitivity — meaning they stop responding significantly to the mechanical stress (Burr, 2002). So after the first few minutes of your run, the bone-building benefits essentially plateau.

2. Monotonous Loading Limits Adaptation

Running applies stress in a predictable, uniform direction. Bones adapt best when exposed to varied forces and bending moments, which challenge the skeletal system to remodel and strengthen. The lack of multi-directional forces in running means some bones — like the femoral neck, pelvis, and spine — may not receive enough stimulus to adapt robustly.

What Actually Builds Strong Bones?

✅ High-Impact, Multi-Directional Activities

• Jumping, hopping, and bounding (e.g. pogo jumps, single-leg hops, box jumps, drop jumps, bounding)

• For added benefit, incorporate change of direction — lateral hops, zig-zag bounds, and agility drills. These introduce variability and strain in different directions, which encourages bone formation.

✅ Heavy Resistance Training

• Muscular contractions, especially during high-load, low-rep strength training, create bone-bending forces that stimulate adaptation.

• Exercises like squats, calf raises, deadlifts, step-ups, and lunges not only load the bones but also strengthen the muscles that protect them.

• Bonus: Resistance training can target sites like the spine and hips, which are typically underloaded in running.

Takeaway

Running is great for cardiovascular fitness and mental health, but it’s not enough to build robust bones on its own.

Bone thrives on variety and intensity — short bursts of high-impact, multi-directional, and resistance-based loading are key.

If you’re a runner looking to reduce injury risk and support long-term performance, integrating these types of training into your weekly routine is essential!

References

• Burr DB, Robling AG, Turner CH. Effects of biomechanical stress on bones in animals. Bone. 2002;30(5):781–6

• Hoenig, T., et al. (2024). "International Delphi consensus on bone stress injuries in athletes." British Journal of Sports Medicine: bjsports-2024-108616.

• Warden, S. J., et al. (2014). "Management and prevention of bone stress injuries in long-distance runners." J Orthop Sports Phys Ther 44(10): 749-765.

• Warden, S. J., et al. (2021). "Preventing Bone Stress Injuries in Runners with Optimal Workload." Curr Osteoporos Rep 19(3): 298-307.