Is walking enough to slow down bone loss?

Brisk walking (30 to 60 minutes, three times a week) can noticeably increase bone density in the lumbar vertebrae and improve balance in older adults with mild bone loss. Walking outdoors during the day offers an added benefit: sunlight stimulates the production of vitamin D, which supports bone formation. This is shown by a 24-week study in people with osteopenia.

For people with osteoporosis (more severe bone loss), the picture is different. Regular walking likely does not reach the loading threshold needed to truly build bone. It may slow the decline to some extent, but a bone-building effect in osteoporosis is not to be expected. A randomised study in menopausal women did show improvements in bone markers and bone density after 8 weeks of structured walking, but that comparison was largely against the participants' own baseline values, which makes the conclusion somewhat more cautious.

Intensive strength training has a far stronger effect on bone than walking. Two sessions per week of heavy resistance exercises over 18 months, combined with increased protein intake, clearly increased bone density in the hip and lumbar vertebrae in older men with both bone and muscle loss. Muscle loss itself also contributes to reduced bone density and raises the risk of falling, so building muscle is doubly worthwhile.

Cycling is a useful comparison to illustrate the principle: competitive cyclists at a high level actually had lower hip bone density than less active younger men, because cycling is not weight-bearing. Movement without ground contact simply does not count for bone.

Combined programmes incorporating aerobic, strength and balance exercises appear to be able to preserve or slightly improve bone, even in more vulnerable older adults who cannot manage heavy training. Comparing such studies with one another is difficult, but this kind of varied approach is regarded as a meaningful alternative when heavy lifting is not an option.