About two weeks ago I posted here showing that cyclists may experience a loss of bone minerals possibly resulting in brittle bones and an increased likelihood of breaks. I mentioned then that I would get back to the topic relative to prevention and treatment. Since then I’ve been reading the scientific literature on the topic. There’s a ton of it, far more than I can possibly cover here. But fortunately, Dr. John Post, TrainingBible Coaching’s Medical Director, is also running a series on bone health on his blog. So I’m going to back off and let him discuss the medical details as that is certainly more in his realm of expertise than mine. Related topics include the effects of aging, hormones, diet, gender, vitamin D and more. So instead I’m going to post one last blog on the prevention of osteopenia and osteoporosis from an exercise point of view.
If cycling seems to have negative consequences for bone health are there other activities; such as weight lifting, running, swimming and walking; that are more beneficial? Below I pose several related questions and searched PubMed for answers.
I use the word “answers” somewhat liberally as there rarely is a definite answer from research studies. When dealing with humans there are many variables that can’t be controlled. And different protocols may produce different results. So one study by itself is seldom an “answer.” The more studies there are on a complex topic such as this one the better the direction – usually. But bear in mind that studies with similar protocols and subjects have been known to produce exactly the opposite results.
So here are 10 questions, a brief summary of the related research and the “answers.” (If you want to dig deeper, click on the study citation and it will take you to the abstract at PubMed so you can read more details for yourself.)
Question #1: Does running improve bone health?
Study Summary: Male and female runners aged 33-94 years had greater tibial (shin) bone strength than sedentary controls of the same age. But the runners also lost bone with advancing age. There was no difference in the radius bone (forearm) between runners and sedentary controls.
Answer: Running appears to make the tibia stronger but there is still a loss of leg bone density with aging in runners. Running did not improve an arm bone health.
Question #2: Is there an activity which is even better for bone health than running?
Study Summary: This is a 1993 review of the scientific literature on the topic. Reviews make my job a bit easier since the author of a review has selected good (usually) studies and done the legwork by compiling and analyzing the data from all. This review reports that the strongest bones have typically been found in power- and strength-trained athletes. “Endurance activities such as long distance running and swimming seem less effective with regard to peak bone density.”
Answer: It appears that lifting weights and participating in power activities (sprinting, jumping, bounding, etc) are more effective than running for bone health.
Question #3: That’s an old study. Is there anything newer?
Suominen H. 2006. Muscle training for bone strength. Aging Clin Exp Res. 18(2):85-93.
Study Summary: From the same author as above only 13 years later, this is a review of the scientific literature looking for the best types of activity for improving bone health. In summary, he says that although aerobic exercise is important in maintaining overall health, a heavy-load, resistance type of muscle training may be better for bone health.
Answer: Yep. Looks like weight training is better for bone health than running.
Question #4: Are you sure lifting weights is better than running? I hate going to the gym.
Study Summary: This is another review to keep me having to work too hard. To quote the authors: “Both aerobic and resistance training exercise can provide weight-bearing stimulus to bone, yet research indicates that resistance training may have a more profound site-specific effect than aerobic exercise. Over the past 10 years, nearly two dozen cross-sectional and longitudinal studies have shown a direct and positive relationship between the effects of resistance training and bone density.”
Answer: There seems to be little doubt that lifting weights is effective for bone health and may be the most effective activity.
Question #5: What about swimming?
Study Summary: This is a review of studies prior to 2009 regarding exercise in maintenance of bone health. This is yet another review showing that exercise activities with high forces (for example, weight lifting) or high impacts (for example jumping and bounding) have the greatest potential for maintaining bone strength. Not all types of exercise have shown positive effects on bone. For example, swimming has no impact on bone mass, while walking has limited positive effects. Exercise involving high impacts, even a small amount, seems to be the most efficient for building bone mass.
Answer: It looks like pushing off the wall of the pool will not build stronger bones.
Question #6: I’m a cyclist and can’t run due to a bad knee. Should I walk instead?
Study Summary: “Regular walking has no significant effect on preservation of BMD at the spine in postmenopausal women, whilst significant positive effects at femoral neck are evident.” Insufficient data was available for the hip.
Answer: The subjects in this study were postmenopausal women, so this may not apply across the board to premenopausal women or to men. However, the research on exercise generally supports the notion that impact is critical in aerobic exercise for bone health. That’s why cycling scores so poorly. The impact forces of walking are much less than that of running and so the effect for those other than postmenopausal women is probably about the same.
Question #7: What if I run more miles? Will that help build bone?
Study Summary: Subjects were tested for tibial (shin) bone strength over a 3-year period. Those who ran more than 30km per week (three groups of subjects ran 5-30, 30-50 or 50-100km per week) had the strongest bones. And the greater the heel strike force the stronger the tibial health.
Answer: Running with higher volume seems to help maintain bone and 30km per week was the threshold for these subjects.
Question #8: If running more is good would doing ultra-running events be the way to go?
Study Summary: A 246-km continuous running race caused significant negative changes in bone health in 18 runners who were subjects. Tests were conducted before, after and 3 days after the race. Bone mineral was lost and bone formation was suppressed afterwards.
Answer: Unfortunately, this study says that doing ultra-distance running races is not beneficial, at least during and in the three days afterwards. I found no studies that did a longer analysis of ultrarunners’ bone health.
Question #9: Since impact force appears to be good for bone, would running faster help?
Study Summary: In this study tibial (shin) bone strength indicators seemed to be related to impact forces (heavy foot strikes). The faster the subjects ran (for example, sprinters vs. distance runners) the stronger the tibia.
Answer: Yes, running faster does seem to be beneficial for bone health. This may not mean running “faster” relative to your best effort, but faster relative to absolute speed. In other words, running really fast, as a sprinter does, is probably key here, not running 8-minute mile pace instead of 9-minute mile pace (although that may help a small amount). Of course, it could just be that having poor technique, running on concrete and wearing thin-soled shoes (or no shoes) is good for bone strength. But I don’t think I’d go these routes just to build up your bones. A better alternative may be to do plyometric exercises or rope jumping.
Question #10: Will trying to lose a few pounds by eating less and running more cause a problem with bone health?
Study Summary: Female, college distance runners who chronically trained at a high volume and did not eat enough to replace calories burned during exercise experienced menstrual dysfunction and bone loss.
Answer: It appears, at least for young women, that eating less and running more over a long period of time is dangerous for bone health.
In Conclusion: I don’t plan to come back to this topic again in the near future unless new research on the topic appears in the scientific literature. So for now, here is what we seem to know about exercise and bone health. It appears the best thing you could do is lift weights. The next best option is exercise that involves high impact such as plyometrics (which has also been shown effective for cycling and running performance). Running, especially more than 30km (18.6 miles) per week, is also effective. Walking may have a limited benefit. Swimming probably has no bone-health benefit.
