Swimming and Walking for Bone Density and Osteoporosis

Swimming works the muscles, cardiovascular fitness and mobility while placing little stress on the joints, but that same feature limits the direct stimulus applied to the bones. To maintain bone density, weight-bearing activities such as brisk walking, stair climbing and strength training are generally more beneficial because they place mechanical loads on the skeleton that encourage adaptation.

Why does walking stimulate the bones differently from swimming?

In water, buoyancy takes away some of the weight the skeleton would otherwise have to support. When walking, every step sends force through the feet, legs and hips. Bone tissue detects these loads as part of its ongoing remodelling process, in which older structures are reabsorbed and new tissue is produced.

This does not mean that running or high-impact exercise is required. For many people, walking at a moderate or brisk pace already provides mechanical stimulation that is not delivered in the same way by activities where the body is supported by water.

• Walking requires you to bear your own body weight;
• Climbing stairs increases the load on the legs and hips;
• Dancing also combines impact with weight-bearing movement;
• Running and small jumps provide greater stimulation when appropriate;
• Intensity should match each person's physical capacity.

Can strength training be even more important than walking?

Resistance training complements impact-based activity because strong muscles pull on bones during squats, rows, exercises with free weights, machines or resistance bands. For this reason, programmes designed to support bone health commonly combine standing exercises with progressive strengthening, rather than relying on one form of exercise alone.

Why does concern increase after the age of 50?

Bone mass changes throughout life, and bone loss can speed up with ageing. In women, the decline in oestrogen during and after menopause particularly increases the rate of bone reabsorption, which is why osteopenia and osteoporosis become more common concerns at this stage.

Exercise is not the only element of prevention, but it provides a stimulus that diet alone cannot replicate. A weekly routine can include a range of movements:

• Brisk walking on safe ground;
• Stair climbing suited to your fitness level;
• Adapted squats;
• Exercises using weights or resistance bands;
• Balance activities to help prevent falls.

Should people who want to protect their bones give up swimming?

No. Swimming remains an excellent activity for cardiorespiratory endurance, muscular strength and maintaining an active routine. It is also particularly useful for people who do not tolerate impact exercise well. The key point is that it may need to be supplemented with gravity-resisted exercise when preserving bone mineral density is also a goal.

• Keep swimming as aerobic exercise if you enjoy it;
• Add muscle-strengthening sessions on other days of the week;
• Include standing activities when they are safe;
• Work on balance and coordination as well;
• Increase load and impact gradually.

The best programme for bones combines load, strength and consistency

There is no single exercise against osteoporosis that suits everyone. Walking provides weight-bearing movement, while weight training adds progressive resistance and can challenge different areas of the skeleton. For people who already have osteoporosis, a history of fractures or significant spinal changes, higher-impact exercises and certain movements need to be adapted to reduce risk.

The main difference compared with exercising in a pool is the type of stimulus the body receives. Water reduces the load on the skeleton; walking, climbing steps and overcoming resistance require bones and muscles to deal directly with external forces. Therefore, people who enjoy swimming do not need to swap the pool for the pavement, but can achieve a more complete routine by combining swimming with weight-bearing, strength and balance exercises.