Bone Health: What Actually Builds It

Bone responds to heavy load and impact — and the assumption that fragile bones need gentle exercise has been tested and found wanting.

What this is

Bone is living tissue that adapts to mechanical strain — high magnitude and high rate of loading, specifically. That means heavy resistance training and impact, rather than walking or swimming, are the stimuli that change density.

This was long considered too risky for the people who most need it. The LIFTMOR randomised trial tested it directly in postmenopausal women with low bone mass: twice-weekly supervised high-intensity resistance and impact training improved bone mineral density and physical function, with no adverse events — a result the authors explicitly framed as contrary to prevailing opinion.

What the evidence says

  • High-intensity resistance and impact training improves bone density

    Gold· human data

    The LIFTMOR trial in postmenopausal women with osteopenia and osteoporosis. Supervised, twice weekly, heavy — and safe in that setting.

  • Load must be heavy or high-impact to change bone

    Gold· human data

    Bone responds to strain magnitude and rate. Walking and swimming have many benefits; changing bone density is not reliably one of them.

  • Adequate calcium, vitamin D and protein support bone

    Gold· human data

    Necessary inputs rather than growth stimuli. Correcting deficiency matters; exceeding sufficiency doesn't add more.

  • Falls prevention matters as much as density

    Gold· human data

    Balance and strength training reduce falls, and falls are the mechanism that turns low density into a fracture. Both halves are needed.

  • Vibration plates and "bone-building" supplements

    Unproven

    Whole-body vibration has small, inconsistent effects; supplements beyond correcting deficiency have little to add. Neither substitutes for load.

What this means in practice

  • Lift heavy, with technique coaching, twice a week. Compound movements that load the spine and hips are the ones that matter.
  • Add impact if appropriate for you — hopping and jumping variations, progressed sensibly.
  • Include balance work; it addresses the falls half of fracture risk.
  • Check protein intake and vitamin D status rather than assuming.
  • If you're at risk, ask your GP about fracture-risk assessment and whether a DEXA scan is warranted.

When to see a doctor

  • A fracture from a fall from standing height or less.
  • Loss of height, or new upper-back curvature, which can indicate vertebral fractures.
  • Long-term steroid use, early menopause, or a strong family history of osteoporosis — worth a risk assessment.

The honest summary

Bone needs heavy load and impact, delivered with coaching. The trial evidence in exactly the population assumed to be too fragile for it shows density and function improving — and gentle exercise, while good for other reasons, doesn't do this job.

Work it out

See also

Frequently asked questions

Can you increase bone density with exercise?
Yes, with the right stimulus. High-intensity resistance and impact training improved bone mineral density in postmenopausal women with low bone mass in the LIFTMOR trial. Low-impact activity like walking and swimming doesn't reliably do it.
Is heavy lifting safe with osteoporosis?
In LIFTMOR, supervised heavy resistance and impact training produced no adverse events in women with osteopenia and osteoporosis. Supervision and technique are part of that result, and existing vertebral fractures change the calculation — get individual advice.
Do calcium supplements build bone?
Calcium and vitamin D are necessary inputs, and correcting a deficiency matters. They don't stimulate bone growth on their own — load does that.

Sources

Written and reviewed by Mathew Beale, MSc Biotechnology, University of Reading.

Last reviewed: