Bone is living tissue that responds to the forces placed upon it. Wolff's Law states that bone will adapt to the loads under which it is placed. If loading increases, bone will remodel itself over time to become stronger to resist that sort of loading.
Walking vs. Swimming/Cycling
Activities like swimming and cycling are excellent for cardiovascular health but offer zero or negligible benefits for bone mineral density because they are non-weight-bearing. Walking is a weight-bearing exercise.
Optimizing the Stimulus
To maximize the osteogenic (bone-building) effect of walking:
- Increase Pace: Faster walking increases the Ground Reaction Force (GRF).
- Add Weight: Rucking adds direct axial loading to the spine and hips.
- Vary Terrain: Uneven terrain forces different angles of loading and engages stabilizer muscles.