Running and Bone Health: Can Cardio Build Stronger Bones?

India has seen an explosive rise in recreational running, whether on treadmills or city streets. In 2024 alone, the top 10 marathons in the country attracted over 2.5 lakh participants, many of whom trained seriously for months. And this is just the tip of the iceberg. The number of people who run daily for fitness runs into the millions, reflecting a growing shift towards movement-led lifestyles across urban India.

Introduction: More Than Just a Heart Workout

Most of us think of running as a cardiovascular exercise, great for your heart, lungs, and perhaps your waistline. But what about your bones?

While resistance training often takes the spotlight in conversations around bone health, low-grade cardio such as brisk walking, jogging, or dancing can play a surprisingly important role in maintaining and improving bone density, especially when done consistently and correctly.

Low-grade cardio refers to aerobic activities performed at a moderate intensity, typically under 65 percent of your maximum heart rate. These exercises are sustainable over longer durations, do not leave you breathless, and often form the backbone of general fitness routines—think brisk walking, slow jogging, swimming, or cycling on flat terrain.

This blog explores how activities like running affect your bones, the science behind mechanical loading, and how to optimise your cardio routine for long-term musculoskeletal (MSK) health.

Bone Health 101: Why Does It Matters?

Bone is a dynamic tissue, constantly breaking down and rebuilding through a process called remodelling. This is governed by Wolff’s Law, which states that bone adapts to the load under which it is placed. This is why sedentary individuals experience bone loss over time, and why astronauts, exposed to zero gravity, lose bone mass despite being otherwise healthy.

However, remodelling is not uniform. Certain bones—like the femur, tibia, and vertebrae—respond more readily to mechanical loading, while areas such as the wrist or ribs are less affected by lower-impact activities.

Peak bone mass is usually achieved by age 30, and maintaining it depends on a balance of loading, nutrition, hormones, and genetics. After this age, bone resorption outpaces formation, especially in postmenopausal women. Read our Comprehensive Guide on understanding bone density and health.

Does Running Help or Harm Your Bones?

Running, especially when performed at moderate intensity and with proper form, can be osteogenic (bone-building). But the story is more complex when you consider loading thresholds, frequency, and cumulative strain.

Why Running Can Help

• Ground reaction forces: Running generates 2.5 to 3 times bodyweight in vertical loading, sufficient to stimulate bone growth at sites such as the femoral neck, tibia, and lumbar spine.
• High strain rate: It is not just the weight but the speed of loading that matters. Bones respond better to brief, rapid impacts than to slow, continuous loading.
• Hormonal effects: In both men and women, consistent cardio has been linked to higher circulating IGF-1 (Insulin-like Growth Factor 1) and growth hormone levels, both supportive of bone anabolism.

Key Insight: A study in Osteoporosis International (2019) showed that short bursts of high-impact activity (even less than two minutes per day) significantly improved hip BMD in premenopausal women compared to continuous low-impact movement.

When running Might Backfire and Harm Your Bones

• Volume without variability: Long-distance running with repetitive, low-impact strides may plateau in osteogenic potential.
• RED-S risk: In female runners, especially those with low BMI, the Female Athlete Triad (low energy availability, menstrual dysfunction, and low bone density) remains a serious concern.
• Stress injuries: Excessive training, especially without progressive loading, increases the risk of tibial and metatarsal stress fractures.

Key Insight: Bone cells become desensitised if exposed to the same load repeatedly. Without variation in direction, intensity, or cross-training, the stimulus becomes ineffective over time.

What About Walking, Cycling, or Swimming?

Walking: Good for maintaining existing bone mass, especially in older adults. However, the mechanical load is close to body weight, which may not exceed the threshold needed to trigger new bone formation.

Cycling: A non-weight-bearing exercise. Studies show that road cyclists have lower spine and hip BMD than runners and even sedentary controls, likely due to lack of axial loading.

Swimming: Water buoyancy removes impact forces entirely. While excellent for joint mobility and cardiovascular health, it provides minimal osteogenic stimulus.

Key Insight: The type of load (e.g. impact versus muscular tension) and site specificity determine effectiveness. For example, tennis improves dominant-arm bone density significantly more than the non-dominant arm, highlighting that bones adapt locally, not systemically.

How to Optimise Cardio for Bone Health

If your primary form of exercise is cardio, here are ways to make it bone-friendly:

1. Include impact: Two to three sessions per week of activities with multi-directional impact (e.g. skipping, short sprints, dance, stair climbing) are more effective than linear jogging alone.
2. Incorporate strain diversity: Vary your movements. Incorporate agility drills, trail running, or uneven surfaces to load bones in different vectors.
3. Combine with strength training: High-strain resistance movements (like squats or deadlifts) complement the repetitive strain of running and target areas cardio misses (e.g. upper limbs).
4. Monitor energy availability: Especially if you want to undertake endurance running. Undereating while training heavily leads to suppressed oestrogen/testosterone and increased bone resorption.

Lumov Advanced Insight: Mechanostat theory suggests that bones require a minimum strain magnitude (1500 to 2000 microstrain) for adaptation. Most everyday movements do not meet this. Intermittent bouts of running, jumping, or lifting are necessary to cross this threshold.

Conclusion: Bones Need Smart Movement, Not Just More Movement

Low-grade cardio, particularly weight-bearing forms like running and brisk walking, can support bone health when done intelligently. Bones respond best to variety, intensity, and adequate recovery.

If your goal is strong, fracture-resistant bones well into old age, make your cardio routine multidirectional, variable, and supported by strength and nutrition. Think less about just clocking mileage and more about loading your bones optimally..

This article is reviewed by Dr. Anurag Gupta, a gold medalist in MPT-Sports Physiotherapy, has worked with elite international and national athletes across football, tennis, and badminton. His clientele includes Srikanth Kidambi (#1 Men’s Badminton Player, Arjuna Awardee, Padma Shri) and Hendra Setiawan (Olympic Gold Medalist, 4x World #1 in Men’s Badminton).

Beyond athletes, Dr. Gupta is the preferred physiotherapist for top founders, including Vivek Gupta (Licious), Rishabh Telang (Cult.fit), and Arjun Chaudhary (former MFine), helping them recover from musculoskeletal issues efficiently.