Which Exercise is Best for Bone Mineral Density? A PhD Study Reveals the Answer

Which Exercise is Best for Bone Mineral Density? A PhD Study Reveals the Answer

Last Updated: July 27, 2025

The Critical Question for Bone Health

For anyone diagnosed with osteopenia or osteoporosis, the primary goal is clear: stop bone loss and, if possible, rebuild it. Doctors consistently recommend exercise, but the advice can be confusing. Is walking enough? Should you lift weights? A landmark 2019 PhD thesis from Ziauddin University provides one of the clearest, most direct comparisons to date, putting three distinct exercise protocols to the test. This study meticulously measured changes in Bone Mineral Density (BMD) to determine which approach yields the best results. This article breaks down the science, the methods, and the definitive findings to help you choose the most effective exercise for your bone health.

Understanding Bone Mineral Density (BMD) and T-Scores

Before diving into the results, it’s essential to understand what’s being measured. As the thesis explains, Bone Mineral Density (BMD) is the average concentration of bone mineral per unit area. It’s the gold standard for assessing bone health.

BMD is typically reported as a “T-score,” which compares your bone density to that of a healthy young adult.

• T-score of -1.0 and above: Normal bone density.
• T-score between -1.0 and -2.5: Osteopenia (low bone mass).
• T-score of -2.5 and below: Osteoporosis.

The goal of any effective exercise program is to maintain or improve this T-score, directly reducing the risk of fracture.

The Measurement Method: Peripheral DXA Scan

To ensure accuracy, the study used a quantitative method for measuring bone health. As stated in the methodology, “Bone Mineral Density of the participants was measured using peripheral DXA Scan (SONOST 3000).”

This device is a small, portable machine that uses a dry gel system to measure the bone density at the calcaneus (heel bone). While central DXA scans of the hip and spine are more common, the study notes that peripheral scans are a reliable, less expensive, and accessible method for tracking changes in BMD. The machine was calibrated before every single use to reduce any margin of error, ensuring the data was robust and trustworthy.

The Contenders: Three Exercise Protocols for Bone Mineral Density

The study set up a direct comparison between three 12-week exercise programs, each performed by a group of postmenopausal women with osteoporosis.

1. The Aerobic Group: Participants walked on a treadmill for 30-60 minutes, 5 days per week, at a moderate intensity (55-75% of max heart rate). This represents a classic weight-bearing exercise recommendation.
2. The Resistance Group: Participants performed a full-body weight training routine using dumbbells, 3 days per week. The intensity was based on their 1 Repetition Maximum (1RM) to ensure the muscles and bones were adequately challenged.
3. The Osteoanabolic (Combined) Group: This group performed both aerobic training and resistance training, alternating between them for a total of 6 exercise sessions per week.

The Results: Which Exercise Improved T-Scores the Most?

After 12 weeks of dedicated training, the BMD of all participants was measured again. The findings were compelling.

The good news is that all three training protocols resulted in a statistically significant improvement in BMD. This confirms that consistent, structured, weight-bearing exercise of any kind is beneficial for bone health.

However, one group clearly stood out. As the data from the Wilcoxon rank test showed, “the median score significantly improved among the participants attending the Osteoanabolic exercise protocol when compared with both aerobic and resistance.”

• Osteoanabolic (Combined) Group: Achieved the greatest improvement. The median T-score improved from -2.6 to -2.2. This was the most substantial change.
• Aerobic Group: Also showed significant improvement, with the median T-score moving from -2.6 to -2.3.
• Resistance Group: Showed the smallest, though still statistically significant, improvement, with the median T-score moving from -2.6 to -2.5.

The study concluded that while all methods work, the combination of aerobic and resistance training had the most powerful bone-building effect.

The Science: Why Combined Training is the Key

The study’s discussion provides a clear scientific explanation for these results. Improving bone density isn’t about just one type of stimulus; it’s about a comprehensive approach to bone remodeling.

The thesis explains, “aerobic training protocol activates osteoblast in order to synthesize bone matrix and inhibit the bone resorption process whereas resistance training protocols enhanced the loading process reducing the bone resorption.”

In simpler terms:

• Weight-Bearing Aerobic Exercise (like walking): The repeated impact of your feet hitting the ground sends signals through your skeleton that stimulate osteoblasts, the cells responsible for building new bone.
• Progressive Resistance Training: Lifting weights creates a different kind of force. Muscles pull on the bones, and this mechanical tension provides a powerful signal to retain and build bone density to withstand the load.

The Osteoanabolic protocol was superior because it provided both types of stimuli. It created a “magnitude of strain that exceeds the threshold required for bone metabolism.” By alternating the two forms of exercise, it kept the body adapting and continuously stimulated the bone remodeling process in a way that neither protocol could achieve on its own.

Conclusion: A Clear Verdict for Your Bones

This PhD research provides a clear and actionable takeaway for anyone looking to use exercise for bone mineral density improvement. While any weight-bearing activity is a positive step, a structured, combined program that integrates both aerobic and resistance training is the most potent strategy for rebuilding bone. The Osteoanabolic protocol used in this study offers a powerful template for creating a workout plan that gives your bones the comprehensive stimuli they need to grow stronger and more resilient.

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Author Bio

Dr. Amna Aamir Khan holds a Doctor of Philosophy (PhD) in Physical Therapy from the College of Rehabilitation Sciences at Ziauddin University. Her research focuses on the effects of targeted exercise interventions on functional parameters in clinical populations.

Source & Citations

Thesis Title: EFFECTS OF OSTEOANABOLIC EXERCISES ON GAIT, BALANCE AND FEAR OF FALL AMONG OSTEOPOROTIC FEMALES
Researcher: Amna Aamir Khan (DPT, MSc)
Guide (Supervisor): Prof. Dr. Pirzada Qasim Raza Siddiqui
University: Ziauddin University, Karachi, Pakistan
Year of Compilation: 2019
Excerpt Page Numbers: 1, 15, 26, 69, 78, 102-104, 127-128

Disclaimer

“Some sentences have been lightly edited for SEO and readability. For the full, original research, please refer to the complete thesis PDF linked in the section above.”

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Have you had a DXA scan, and what type of exercise has your doctor recommended for your bone health? Share your experience in the comments below!