Tag Archives: cycling

New Bike Day! The GT Grade

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Hi all. It’s been a while. So long, in fact, that I couldn’t even remember how to log in. I’m hoping for more consistent posts in the near future.

Anyway–last Saturday was new bike day. A GT Grade, carbon fiber, Ultegra group with HYDRAULIC BRAKES (more about that in a moment).

Margot  was kind enough to drive me up to Saugerties, where I picked up the bike at Revolution Bicycles. Normally I’d go with my local shop, the Bicycle Depot in New Paltz, because I know and trust them and they have provided nothing but excellent service, but they are not a GT dealer. In any case, Revolution Bicycles was great. We did the final set up of the bike while I waited, which included removing the crappy tires it came with and putting on Compass Stampede Pass Extralight 32 mm tires and switching the seatpost to something more suitable.

Once set up, I set out on a planned 51-mile ride back home. Yeah, I know it’s dumb to ride an untried bike in an isolated area without a proper shakedown cruise, but that’s what I did. And the bike turned out to be so good that I took a few detours and ended up riding much farther–and climbing many more feet (~4300) than originally planned.

Revo-Home Map

Here’s the bike.

The only issue that cropped up was that the saddle was set way too far forward, which I didn’t really notice until about 20 miles into the ride. Of course, I ignored it for another 10-15 miles and ended up with terminal crippling ass pain. I got off the bike and slammed the saddle back to where it should have been, and things improved greatly.

Now, the bike: Spectacular. I’ve been a Campagnolo proponent for a long time, and I begrudgingly use SRAM on one bike although, I have to admit, I really hate it. So this was my first time on modern Shimano, and my first time with hydraulic brakes. Can I say HOLY SHIT HYDRAULIC BRAKES! I’ve been riding a bike with mechanical discs and I hated them. When they weren’t rubbing they weren’t braking, and vice versa. Hydraulic discs truly change the riding experience.

Like most of you with caliper brakes, I rarely touch the rear brake except in 3 situations: 1) When I’m riding on icy roads (to avoid a front washout and a crash); 2) when I’m riding on gravel (again, to avoid locking up the front); and 3) when I’m descending something long and twisty to give the front brake a break before the rim turns cherry red. Hydraulic brakes, on the other hand, provide a perfectly functional rear brake that, if you hang your ass off the back of the saddle, is nearly as functional as the front. That means much faster, more confident descending. I’m actually surprised the pros haven’t switched yet–it’s that much better and a hell of a lot safer than caliper brakes.

Only one picture from this ride:

John F

medicalwriter.net

Glucosamine and Chondroitin for Knee Pain: What’s the Evidence?

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If you’ve been reading along, you know that I’m taking a week or two off from longer rides because of knee pain. I don’t think there’s anything wrong with my fit, it’s clearly from pushing too big a gear up extended 20% grades, plus a saddle collapse that put me almost a centimeter below my usual position. The knee pain really started after a long, long cat 1 climb in the northern Catskills. I’m feeling much better now, but I’m still only going for daily 10-15 mile rides, rather than the 80- to 120-mile rides I prefer. I’ve also, much to my disgust, replaced my Brooks Swallow saddle. I wish something else worked for me, because I don’t like spending $300 on a new saddle every 6000-7000 miles, which amounts to only a year of riding for me—probably less now that I live somewhere that is much more conducive to riding.

So now I have a new found interest in treating and preventing knee pain. My girlfriend, who is a runner, swears by glucosamine/chondroitin supplements, together with krill oil. Being a biomedical scientist, I asked, what’s the evidence?

Before you read this, I want you to keep in mind that I have my own inherent bias, in that I want the supplements to work; also remember that I wrote this post in 15 minutes at 10:00 at night, so it is far from a complete assessment of the current literature!

The GAIT trial was a prospective (meaning planned in advance) 24-month, placebo-controlled study conducted in 572 patients who, at baseline, satisfied criteria for osteoarthritis of the knee. These patients were randomly assigned to several treatments: glucosamine, glucosamine plus chondroitin sulfate, the COX-2 inhibitor celecoxib (a non-steroidal anti-inflammatory drug, like naproxen, with somewhat different properties), or placebo. The primary outcome measure was a 20% decrease in knee pain from baseline to week 24.

Unfortunately, GAIT showed that there were no significant differences among the groups in terms of response: the placebo response rate was 60.1%, whereas the response to glucosamine was only 3.9 percentage points higher, and the response to the combination was 5.3 percentage points higher.

On the other hand, the STOPP trial, which was published in 2009 in the generally high-quality journal Arthritis and Rheumatism, found that there was a significant reduction in joint-space width loss and a significantly more rapid improvement in pain among patients who received chondroitin sulfate, with no safety issues. While I would ordinarily discount a single study, this represents the largest single prospective study of chondroitin in the literature that I am aware of (I’m not writing this for work, so I’m being a little casual about my research). But it’s not much bigger than the previously noted negative trial. Again, this study was conducted in patients with pre-existing, relatively severe osteoarthritis.

The results of these small trials are interesting, but given their small size and the fact that they enrolled patients with osteoarthritis that was fairly significant (and thus, a group that is unlikely to be participating in exercises that stress the knee), they don’t have a lot of relevance for your average active athlete. Another study, conducted in Navy Seals, found that knee osteoarthritis symptoms were relieved in patients who took the active treatment, which in this case included glucosamine, chondroitin, and manganese ascorbate. This study may be the most relevant to the average athlete, as Navy Seals, one would suspect, are reasonably active.

Now, what about meta-analyses? Meta-analyses combine data from multiple trials, and are often considered to be the best evidence for or against a treatment. Unfortunately, we get contradictory results here as well. A recent meta-analysis, published in 2010 in BMJ, assessed the efficacy of glucosamine, chondroitin, and placebo, again in patients with preexisting osteoarthritis, and found no evidence for efficacy in terms of joint-space narrowing or functional/pain outcomes. Again, all of the studies were conducted in patients with pre-existing, relatively severe osteoarthritis. However, several earlier meta-analyses identified clear benefits associated with these supplements

Setting aside the meta-analyses, which could contradict each other for any number of methodologic reasons, why are the results of the STOPP and GAIT studies discordant? I think GAIT was poorly designed and run. First, the GAIT study had an extraordinarily high drop-out rate. Second, the study used an older radiologic technique to assess joint space narrowing. Third, GAIT used a low threshold to identify responders—a threshold so low that it could easily be reached by many patients in the placebo arm, eliminating any chance to identify a significant difference between active treatment and control.

It seems like the evidence is equivocal, as so much is in medicine. So what am I going to do? Neither glucosamine nor chondroitin appear to have significant side effects, so I am going to keep taking them.

John

medicalwriter.net