For years, women with low bone density were told to avoid lifting anything heavy. The LIFTMOR trial (Watson et al., 2018) put that advice to the test — and found the opposite was true.
What they did
The trial randomized 101 postmenopausal women with low bone mass (average age 65). Half did supervised, high-intensity resistance training: barbell deadlifts, back squats and overhead presses at more than 85% of their one-rep maximum, for 5 sets of 5. They added a jumping chin-up with a drop landing for impact. Just two 30-minute sessions a week, for eight months. The first month was a lighter on-ramp to master technique before the load went up.
What happened
Over eight months the training group gained bone where the control group lost it. The exact changes reported in the trial:
| Measure | HiRIT group | Control group |
|---|---|---|
| Lumbar spine bone density | +2.9% | −1.2% |
| Femoral neck (hip) bone density | +0.3% | −1.9% |
| Femoral neck cortical thickness | +13.6% | +6.3% |
| Height (stature) | +0.2 cm | −0.2 cm |
In plain terms: the program built spine density and preserved hip density and height, where the low-intensity exercise group lost all three. (The method has a name — HiRIT.) Back and leg strength and functional tests like sit-to-stand also improved significantly. (The femoral-neck density gain was small in absolute terms — the meaningful result there is that the training group held its ground while the control group dropped 1.9%.)
Just as important was the safety record: adherence was 92%, and across the whole trial there was a single minor adverse event (a brief lower-back spasm). But this was closely supervised — a maximum of eight participants per instructor — and the researchers are explicit that they do not recommend replicating it without supervision, because technique can't be self-monitored under heavy load.
How Bone Builder uses it
Bone Builder uses this research as background for exercise education. Its Peak track is not the trial protocol, and the app has not demonstrated the trial’s outcomes. The questionnaire does not establish clinical clearance; higher-intensity work requires an individual assessment and direct supervision. Foundation and Build do not automatically qualify someone for Peak.