More on Bone Health

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?

Wilks DC, Winwood K, Gilliver SF, Kwiet A, Sun LW, Gutwasser C, Ferretti JL, Sargeant AJ, Felsenberg D, Rittweger J. 2009. Age-dependency in bone mass and geometry: a pQCT study on male and female master sprinters, middle and long distance runners, race-walkers and sedentary people. J Musculoskelet Neuronal Interact. 9(4):236-46. 

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?

Suominen H. 1993.Bone mineral density and long term exercise. An overview of cross-sectional athlete studies. Sports Med. 16(5):316-30. 

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.

Layne JE, Nelson ME. 1999. The effects of progressive resistance training on bone density: a review. Med Sci Sports Exerc. 31(1):25-30. 

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?

Guadalupe-Grau A, Fuentes T, Guerra B, Calbet JA. 2009. Exercise and bone mass in adults. Sports Med. 39(6):439-68

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?

Martyn-St James M, Carroll S. 2008. Meta-analysis of walking for preservation of bone mineral density in postmenopausal women. Bone. 43(3):521-31.

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?

Deriaz O, Najafi B, Ballabeni P, Crettenand A, Gobelet C, Aminian K, Rizzoli R, Gremion G. 2010. Proximal tibia volumetric bone mineral density is correlated to the magnitude of local acceleration in male long-distance runners. J Appl Physiol. 108(4): 852-7.

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?

Kerschan-Schindl K, Thalmann M, Sodeck GH, Skenderi K, Matalas AL, Grampp S, Ebner C, Pietschmann P. 2009. A 246-km continuous running race causes significant changes in bone metabolism. Bone. 45(6):1079-83.  

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?

Wilks DC, Winwood K, Gilliver SF, Kwiet A, Chatfield M, Michaelis I, Sun LW, Ferretti JL, Sargeant AJ, Felsenberg D, Rittweger J. 2009. Bone mass and geometry of the tibia and the radius of master sprinters, middle and long distance runners, race-walkers and sedentary control participants: a pQCT study. Bone. 45(1):91-7. 

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?

Pollock N, Grogan C, Perry M, Pedlar C, Cooke K, Morrissey D, Dimitriou L. 2010. Bone-mineral density and other features of the female athlete triad in elite endurance runners: a longitudinal and cross-sectional observational study. Int J Sport Nutr Exerc Metab. (5):418-26. 

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.

Comments

[Gregg]

Great information, but here's a question I haven't really seen answered anywhere: is mountain biking good for bone health? is it better than road cycling? how does it compare to weight lifting?

Intuitively I feel like the rough terrain and the constant jarring and constant lifting of the front end of the bike for example would provide some benefit for bone health.

Thanks for your thoughts on this subject.

[Johan Moraal]

How about mountain biking without any suspension? I have a feeling that could be good for at least bones in lower back and shoulders.

[Joe Friel]

Gregg--Working off of my memory now (that can be a bit shaky) but I recall coming across a study of MTBers that found it was a bit better than road cycling for bone health.

[Doug Jansen]

Joe - thanks for bringing attention to this important topic. I'm 48, compete on and off road, and have trained 500+ hours per year for the last decade. I cross train in winter months with skate technique XC skiing. Weight bearing, but no impact. I did no other weight bearing activity.

Last spring, while riding an easy off-road trail at a slow pace, I dabbed and rolled my ankle. A few hours later, a plate, six screws and two pins held my tib/fib together. What happened was too benign to cause that kind of damage.

After a full recovery, I got a bone density scan, since I heard about low bone density in cyclists. Sure enough, I have osteopenia, and my left hip is actually categorized as high risk of fracture. My doctor gave me choice of risky prescription drugs or add impact activity to my routine. Obviously I opted for the latter.

I began running, which was unpleasant to start. I do not plan to run more than one hour per week. From survey of studies, it sounds like short, intense runs may be more effective than long, slow runs. I've never been one for indoor workouts, so not sure if I could adopt a plyometrics routine. Is it unwise for a fit person my age to take up running? It is tough to ease into, since I have a substantial cardio base.

Thanks again for this series of posts. Lots of pertinent information here.

[Madeleine]

I think the article Gregg might be interested in is Sally Warner’s University of Utah PhD thesis, eventually published as Warner SE et al. Bone mineral density of competitive male mountain and road cyclists. Bone 2002; 30(1): 281-6. “In conclusion, endurance road cycling does not appear to be any more beneficial to bone health than recreational activity in apparently healthy men of normal bone mass. Higher bone mineral density in the mountain cyclists suggests that mountain cycling may provide an osteogenic stimulus that is not inherent to road cycling.”

To the extent that an adequate intake of calcium is important to bone health, it is nice to see that calcium is part of the mineral composition of some energy drinks and gels (e.g. Gatorade Recover, Hammer RecoverRite, Gu gel packets and Gu recovery brew), though it isn’t in most of the products these brands propose for use exercise (Gu Gel seems to be the exception) – Joe, do you know why? Replacing calcium losses from sweating in real time, as it is occurring, seems like it might do a better job at protecting bones than a once-a-day supplement.

[Joe Friel]

Doug Jansen - Thanks for your personal insight. Very interesting and probably much more likely to get peoples' attention than research. As to your question, I see no reason why a 48 year old shouldn't or couldn't successfully add a running routine. Good luck!

[Carrie]

great info!! i'm just getting into running and i didn't realize how good it was for my bones!

[Calvin Gehlen]

Thanks for your post.

I'd be interested to see if sport-specific strength training such as run/bike hill repeats would also have a positive effect on bone health.

Certainly from the studies you have noted, there's a lot of good reasons to hit the resistance exercises in addition to the usual swim/bike/run

[John Post, MD]

Joe - excellent review as usual. I think the take home lesson as we understand it in 2011 is that awareness and concern are half the battle. Few of us at 25 think about our health status at 65...but we're beginning to. Being cognizant that choices of what we do and what goes in our mouths in 2011 have a direct effect on our state of well being in 2051 is a great start!

Thanks, John Post, MD

[Jack]

Thanks for this post. As a tennager i got into quite serious 400/800m track training. Then i experienced some teeth problems thay i had never had before. I think it's due to insufficient level of minerals and maybe some vitamins. Do You think it's possible?

Thanks, Jack

[Greg Damian]

About five years ago, I was also diagnosed as osteopenic. I had been a middle distance runner and triathlete for 15 years. I was 43. Over the last five years I have shifted my exerice to focus on weight lifting and away from cycling and swimming. I have seen slow but steady improvements in my bone mineral density in followup scans.

Greg

[Rutger]

HI

I just found this blog (just started mountainbiking)so this will be my first post.
On the matter of deminaralisation, if i remember correctly
Osteoclasts (cells that break down bone ) are stimulated by protons (H+) this stimulation causes an efflux of calcium (Ca2+) So its part of the proton buffering system and delays acidification.

So sports on and like cycling and long distance running (long duration at or above Anearobic threshhold) could lead to (temporary) demineralisation.

weight lifting probably leads to "thicker" bone via hormonalpath ways (increase in testosteron!?)