Can you still build bone mass in your fifties?

Building bone mass after fifty is probably not realistic. What is achievable is slowing the loss considerably. In a randomised study of 160 obese older adults, hip bone density fell by 3% in people who did cardio training alone. Those who combined it with strength training lost only 1%. New bone was therefore not being formed, but the loss was clearly limited.

Bone mass built up earlier in life counts for a great deal. People who were physically active throughout their lives have more bone mass around the age of forty than those who were not. That larger 'bone reserve' pushes back the point at which osteoporosis causes clinical symptoms. This makes what you did in your younger years, or are still doing now, relevant to your future health.

What causes bone mass to shrink most rapidly is weight loss achieved purely by cutting food intake, without additional exercise. This comes at the expense not only of fat mass, but also of muscle and bone tissue. Particularly in people aged fifty and over, this worsens the normal age-related loss. Exercise is therefore not a supplement to a diet, but a necessary counterweight.

International guidelines for osteoporosis recommend weight-bearing exercises and strength training as the standard non-pharmacological measure for people aged fifty and over. Think of walking, climbing stairs, dance classes or resistance exercises. Aerobic fitness training also helps, but strength training appears to protect bone better. A considerable proportion of what people regard as inevitable bone loss is linked to too little exercise and insufficient protein and other nutrients, and is therefore partly preventable.