Does long distance running help build bone? And how can we tell?
A study published in the Journal of Exercise Rehabilitation looked into these questions. The authors followed marathon runners and people who don't exercise and tracked their bone density and biochemical markers that indicate bone growth. As they noted, the focus on long distance specifically was important—previous research has shown mixed effects of running on bone density.
The study measured bone densities in the radius (forearm) and tibia (shin bone), and found that there was no statistically significant difference between runners vs. non-exercisers. They also looked into osteoclastin and deoxypyridinolin, two indicators of bone formation and resorption. While deoxypyridinolin levels between the two groups weren't statistically different, that wasn't the case for osteocalsin.
One difference seen in the study between marathon runners and people who don't exercise was higher osteocalsin levels in runners. Osteocalsin levels in the blood are used as an indicator of bone formation. As the authors suggested, the significantly higher osteocalcin levels indicate that this type of running can help increase bone production.
While this study is a good baseline of how long distance running can affect bone health, we still need a lot more information. For example, this study looked specifically at a younger population—people mostly in their 30s and 40s—and a non-osteoporotic population. How does long distance running impact bone density for people who have osteoporosis? That's a question we need more research on.
Our article on osteoporosis and running dives deeper into the basics of what we know right now. If you are thinking about taking up running, or have recently been diagnosed with osteoporosis, talk with your doctor about what is best for you.