Auto Ads by Adsense

Sunday, July 05, 2009

Cycling is not good for your bones

It appears that there's been a spate of research showing that cycling is not good for your bones. When someone posted this to a cycling mailing list, someone asserted that since the studies were only done on competitive cyclists, it probably wouldn't matter to recreational cyclists.

What kind of people join cycling mailing lists? Enthusiasts. These are folks who are enthusiastic enough to bike to work every day, go on cycling vacations, and bike on weekends, so unfortunately, if that describes you (and it certainly describes me!), you're at risk.

In 2005, just before the Tour of the Alps, Lisa and I got ourselves tested as a precaution. Sure enough, our bone density was T -1.5, which is osteopenia. Osteopenia is not really a disease --- it just means your bone density is below normal, and you're at risk if you don't change course.

So change course we did. After the Tour of the Alps, I cut back on my cycling by about 50%. This meant that one weekend day was devoted to hiking (we tried running --- it was no fun, so we knew we couldn't keep it up). 2006 was devoted to the Coast to Coast walk, and we didn't do as much cycling as we normally did (note that cutting back 50% still meant I was doing 6000 miles a year from commuting and fun rides). I added weight lifting to my exercise regime, forcing myself to spend time in the gym for the first time in my life. I also added calcium supplements to my diet.

In 2007, we got tested and we had gone from T -1.5 to T +1.5. Not only were we in the normal range, we now had stronger than normal bones! The lab technician stared at me when she did the bone scan, and stared at her records again, because she had never seen such a radical change in so short a time! Her comment was, "You changed something didn't you?" My doctor looked at the report and said, "Wow, when I told you to take up hiking, I didn't expect you to walk across England. I don't even have to test you for another 5 years. Keep doing whatever you're doing." (The funniest things about doctors is that they always seem genuinely surprised whenever a patient takes their advice --- I certainly don't pay my doctors just so I can ignore them!) We did do a Vitamin D test though, and it seemed that I had low vitamin D --- my skin's too dark even for Northern Californian sun to give me much vitamin D naturally.

Incidentally, after I posted my results to a cycling forum, someone sent me e-mail with calculations showing that I couldn't possibly have made such a big difference so quickly. When I inquired as to why he was skeptical, he responded that he tried lifting weights and hiking but it made no difference to him. Further probing revealed that he was in his late 50s, and more importantly, had not cut back on his cycling --- he was still doing double centuries. It is very important to realize that if you've been diagnosed as having a problem, you cannot just keep going as though nothing has changed --- you have to cut back on the ultra long rides that are doing the damage!

So if you're one of those enthusiastic cyclists, you need to go get yourself checked so you can do something about it. And it is possible to do something about it. I certainly didn't give up cycling --- and I didn't have to. There are sacrifices --- for instance, my trips can no longer be as tough as the one I did in 2005 --- subsequent trips did not feature as much climbing. I might even have to schedule rest days this year as part of the Tour of Hokkaido, but you know, being able to go for a fun hike and not be sore for 2-3 days afterwards is worth something, and as mentioned before, the Coast to Coast turned out to be a great trip.


Unknown said...

Interesting, I'd think that the more you use your muscles *regardless* of intensity, the stronger your bones would get.

I wonder what is the scientific reason that cycling would decrease your bone density. One explanation that I can think of is maybe your body needs to dedicate more of its resources into repairing cardio/muscle. However, I'm not a bio-med guy so this guess is probably way off.

Piaw Na said...

It turns out that weight bearing is really important, so swimming, for instance, also does nothing for your bone density. It doesn't leach calcium out of your bones like cycling does, because cycling is non-weight bearing and you sweat out calcium when you ride.

Unknown said...

I used to play tennis but had to quit due to joint problems. I've had a really bad knee problem and my doctor has recommended cycling or swimming.

I've always thought swimming was much more similar to cycling than say, tennis, basketball or football... both swimming and cycling are less stressful on the joint, and you do actually sweat when you're swimming.

Piaw Na said...

Not surprisingly, my bike club is full of former tennis players who did what you did. If not for the bone issue, cycling is the perfect sport. There's nothing else like it. I used to enjoy swimming as a kid, but I definitely don't enjoy the cold water in this area, and chlorine pools are just no fun.

Peter said...

Any update on this? Subsequent studies have confirmed bone loss with cycling, but I'm wondering if standing up while riding up hills would turn cycling into a somewhat of a weight-bearing exercise? Or maybe riding on rough roads ...

Piaw Na said...

No, I haven't seen any significant new studies that added anything. The whole body vibration thing is interesting, indicating that perhaps mountain biking is better for your bones.