The link between physical activity and increased bone density is widely recognized. However, recent research has found that just being active is not enough to build strong bones or slow osteoporosis. In fact, certain physical activity can lead to bone loss.
In 2009 the Bone & Joint Injury Prevention & Rehabilitation Center at the University of Michigan revealed the findings of their research review from 1961 to the present. The researchers found three characteristics about different types of activity that had the most impact on increases in bone density.
1. The first is the amount of strain placed on the body. A good example of this is heavy weight lifting. You need to create a high enough magnitude of strain on the body to improve bone density.
2. The second is the rate of strain of the activity, one of the highest activities for this would be jumping.
3. The third characteristic is the frequency of the strain on the bone. Activities like running would produce the greatest increases in bone density because the impact is occurring so frequently.
The research did not determine which characteristic was most important, but that to increase bone density you must do activities that include all three. Research has found that increases in bone density can be made in as little as 5-20 minutes of weight bearing or muscle strengthening activity each week.
Building bone density can be made at any age, regardless of bone health, as long as you place enough force on the body that the muscles are pulling the bone. The force of a muscle pulling against the bone is what stimulates bone growth. This is why the researchers stated that activities like swimming or water aerobics, while good to improve cardiovascular strength, did nothing to produce bone growth. There simply was not enough force being placed on the bone since the body is not in a weight-bearing position.
The best thing you can do to build your bone or slow bone loss is to include weight bearing activities that place the most amount of strain with the highest rate and frequency that you can handle.