Does walking do enough to maintain your muscles?

Walking is not enough to actively build or properly maintain muscle. The mechanical stimulus that walking provides is too light to drive muscle growth. What walking does do is make muscles more sensitive to the protein you eat, which slows muscle loss slightly. That effect can be seen even with short walks in hospital settings, where staying in bed would otherwise lead to rapid muscle loss.

For anyone who genuinely wants to maintain or build muscle, strength training is the way to go. Resistance and strength exercises increase muscle mass and muscle strength in a way that walking simply cannot match. This is all the more true for older adults: without sufficient muscle loading, lean mass declines by around 15% between your thirties and eighties in people who are largely inactive. This goes hand in hand with a lower basal metabolic rate, a greater risk of falls, and poorer insulin sensitivity.

The strongest results come from a combination of strength and cardio training, supplemented by adequate protein intake. After bariatric surgery, a group that combined both forms of training lost an average of 2.6 kg less muscle mass than people who did not train at all. And in older adults with reduced muscle function, twelve weeks of combined training plus nutritional support produced a measurable improvement in walking speed (plus 0.24 metres per second) and grip strength, with no adverse effects.

High-intensity walking, such as sustained intensive cycling over many years, appears to limit muscle loss in older age more effectively than ordinary walking. However, that study was very small and observational, so no firm conclusions can be drawn from it. As for bone density, walking at best stabilises the loss rather than reversing it: that requires a heavier load than walking can deliver.

Walking certainly has value, especially as part of an active lifestyle or if you are not yet able to start strength training. But if you want to preserve muscle as you age, walking as your only form of exercise is not sufficient. Combine it with strength training and make sure you get enough protein in your diet.