Why Getting Stronger Builds Better Bones
What the LIFTMOR Trial Teaches Us About Deadlifts, Bone Density, and Progressive Strength
We’ve known for years that strength training supports bone health. Insights from the LIFTMOR trial show us that it’s not just doing the exercises that matters, but also how heavy you lift that matters. In this landmark study, postmenopausal women with low bone density performed supervised barbell training twice per week, including deadlifts, squats, and overhead presses. All participants in the lifting group improved their bone mineral density (BMD), but the women who got the strongest saw the biggest gains in BMD.
Let’s explore what that means, why it matters, and what it teaches us about how bones respond to training.
Lifting Heavier = Building More Bone
In a detailed follow-up analysis of the LIFTMOR trial, researchers compared each participant’s maximum deadlift weight to her change in lumbar spine bone density over 8 months.
Here’s what they found:
Women who deadlifted more weight experienced larger gains in lumbar spine BMD
The relationship had an R² of 0.17, meaning 17% of the variation in spine bone improvement was explained by deadlift strength alone
This association remained even after adjusting for age, baseline bone density, and body weight
Why Heavier Loads Stimulate Bone
Bones are not static structures. Bone is living, dynamic tissues that respond to stress. When you apply heavier forces (like during strength training), your body senses the strain and reinforces the bone in response.
Here’s the biological process:
Mechanical load stimulates the skeleton, particularly in weight-bearing regions like the spine and hips
Osteoblasts, the bone-building cells, are activated to lay down new bone matrix
Bone remodeling occurs over time, resulting in denser, stronger bone
Deadlifts are especially effective because they target the spine, pelvis, and hips—common sites for osteoporotic fracture.
Is This Kind of Lifting Safe?
Yes! In the LIFTMOR trial, participants trained at up to 85% of their 1-rep max, which qualifies as high-intensity loading. Yet the safety record was excellent:
Zero fractures
Zero serious injuries
Only 3 minor musculoskeletal events (e.g., mild back strain), all of which resolved without medical intervention
What This Tells Us About Bone Health
The key insight from this analysis is simple but powerful: it’s not just what you do, it’s how strong you become doing it. This reinforces the importance of progressive overload, the principle of gradually increasing resistance over time to stimulate ongoing bone adaptation. The more you improve in strength, the greater the mechanical signal for your bones to remodel and grow stronger. In practical terms, this means tracking and increasing your weights regularly, focusing on large, weight-bearing movements like deadlifts and squats, and maintaining consistency over many months. The LIFTMOR data suggests that your rate of strength improvement may directly influence how much bone you gain.
References
Watson S, Weeks B, Weis L, Horan S, Beck B. High-intensity resistance and impact training improves bone mineral density and physical function in postmenopausal women with osteopenia and osteoporosis: the LIFTMOR randomized controlled trial. J Bone Miner Res. 2018;33(2):211–220.
Weeks BK, Beck BR. The LIFTMOR trial: Further analysis reveals dose-response relationships between strength and lumbar spine BMD gain. Presented data, 2019.
Wolff J. Das Gesetz der Transformation der Knochen. (The Law of Bone Transformation). 1892.
Daly RM, Dalla Via J, Duckham RL, Fraser SF, Helge EW. Exercise for the prevention of osteoporosis in postmenopausal women: an evidence-based guide to optimal prescription. Braz J Phys Ther. 2019;23(2):170–180.