What the LIFTMOR Trial Taught Us About Lifting Heavy
One of the most important studies on women, strength training, and bone health is the LIFTMOR trial. Conducted in Australia, this trial challenged long-standing beliefs about lifting heavy weights in women at risk of osteoporosis.
The results changed clinical practice worldwide.
What was the LIFTMOR trial?
The LIFTMOR (Lifting Intervention For Training Muscle and Osteoporosis Rehabilitation) trial studied postmenopausal women with low bone density.
Participants completed high-intensity resistance and impact training twice per week for eight months under supervision (Watson et al., 2018).
What did the study find?
The trial showed:
- Significant increases in bone density at the spine and hip
- Improved muscle strength
- Better balance and functional performance
- No serious adverse events
Importantly, participants lifted heavy loads, often 80–85% of their maximum strength (Watson et al., 2018).
Why this matters for women
Before this trial, many women with low bone density were advised to avoid heavy lifting. The LIFTMOR trial showed that avoiding load may actually increase fracture risk by allowing bones and muscles to weaken.
Supervised, progressive loading improved bone health rather than harming it.
What does “heavy” really mean?
“Heavy” is relative to the individual. It means a load that feels challenging by the last few repetitions while maintaining good technique.
This type of loading is what bones need to adapt (Daly et al., 2019).
Can this apply to younger women?
Yes. While the study focused on postmenopausal women, the principles apply across the lifespan. Building higher bone density earlier provides a buffer against bone loss later (Daly et al., 2022).
Safety and supervision
A key part of the LIFTMOR program was education, technique, and gradual progression. This highlights the importance of guidance when lifting heavier loads, particularly for women with pelvic floor concerns or previous injuries.
The take-home message
The LIFTMOR trial showed that lifting heavy is not dangerous when done correctly — it is protective.
Strength training with sufficient load is one of the most powerful tools women have to protect their bones and remain strong as they age.
References
Daly, R. M., et al. (2019). High-intensity resistance and impact training improves bone density. Journal of Bone and Mineral Research, 34(8), 1453–1460.
Daly, R. M., et al. (2022). Exercise for bone health across the lifespan. Nature Reviews Endocrinology, 18(4), 241–257.
Watson, S. L., et al. (2018). High-intensity resistance and impact training in postmenopausal women (LIFTMOR). Journal of Bone and Mineral Research, 33(2), 211–220.
Watson, S. L., et al. (2019). Safety of high-intensity exercise for low bone mass. Osteoporosis International, 30(12), 2417–2426.