Ask ARN: Does aquatic therapy effect bone density in patients with osteoporosis or osteopenia?

The Aquatic Resources Network gets questions from clinicians each day. We think everyone should learn from the answers!

Question: How does aquatic exercise or therapy effect bone density? It would seem that the reduction in weight-bearing which occurs with water-based exercise would diminish the benefits for bone retention.

Answer: The answer is two-fold. Yes, exercising in the pool will reduce the amount of joint compression and weight-bearing performed during a given task (isn't that what we love about aquatic exercise?).

Thus, a given gravity-based task "should" result in greater bone preservation (and perhaps even growth) than its water-based cousin.

However, weight bearing is not the only way to lay-down (or preserve) bone. Strength training exercises, which cause the muscles of the body to pull on their respective bones, can also effect bone density. And aquatic exercise has been shown to create enough pull to have a positive effect on bone.

Bibliography on bone density, body composition and aquatic exercise...

Here is the conclusion of one study addressing this very issue:

Ay et al (2005): Although weight-bearing physical activity is known to be superior to non-weight-bearing activity to increase the bone mass, our present evidence shows that aquatic and weight-bearing exercises both can increase calcaneal BUA.

More studies are listed in the bibliography provided above.