Tag: cycling

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Delhi 2010: WADA’s thoughts on Contador

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My new Sweat Science columns are being published at www.outsideonline.com/sweatscience. Also check out my new book, THE EXPLORER'S GENE: Why We Seek Big Challenges, New Flavors, and the Blank Spots on the Map, published in March 2025.

- Alex Hutchinson (@sweatscience)

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I’ve arrived safely in Delhi, where I’ll be covering the Commonwealth Games for the next two weeks (and my accommodations are just fine, thank you very much!). My main mission will be to gather material for a couple of upcoming stories on cutting-edge sports science and medicine, but I’ll also blog regularly about what I see.

A quick taste before I head to bed: WADA held a press conference today featuring director general David Howman. He danced around a couple of questions about Alberto Contador, but he did say that he’s been happy with how the case has been handled, and hasn’t seen any evidence that cycling authorities have been procrastinating in pursuing the case (despite pointed accusations to the contrary by a German TV station). He also spoke briefly about what dopers are up to now — specifically microdosing (something that could well be relevant to Contador), sample manipulation (e.g. the Russian women caught giving someone else’s pee in 2008), and testosterone patches. Here’s a brief clip of him answering a question about how WADA scientists can hope to stay ahead of the cheaters (in which he demonstrates his high opinion of journalists!):

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How to pedal efficiently: “dead centre size”

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My new Sweat Science columns are being published at www.outsideonline.com/sweatscience. Also check out my new book, THE EXPLORER'S GENE: Why We Seek Big Challenges, New Flavors, and the Blank Spots on the Map, published in March 2025.

- Alex Hutchinson (@sweatscience)

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[UPDATE 9/17: Check out reader Phil Koop’s analysis of the paper in the Comments section of this post. Definitely worth a click.]

An interesting Norwegian study on pedalling efficiency has been posted online at Medicine & Science in Sports & Exercise, proposing a new measurement to determine whether cyclists are getting the most out of their pedal strokes.

The basic goal of cycling, obviously, is to convert your effort into forward motion of the bike. To do that, experts have long believed that a quantity called “force effectiveness ratio” (FE) should be optimized. FE basically tells you how much of the force you’re applying with your foot at any given moment is directed perpendicular to the crank. For example, when the crank is parallel to the ground and you’re pushing straight down, FE is very high. But when the pedal is at the very bottom of the cycle, if you’re still pushing down instead of back, your FE will be lower. Averaged over the whole pedal stroke, a typical FE might be about 50%.

This makes sense in theory, but no one has been able to show that better cyclists have higher FE (at least if you’re comparing elite and sub-elite, as opposed to complete novices):

From an energetic-mechanical point of view, this should be the best “technique” parameter because the energy used for producing the ineffective, static component of force will not contribute to external power. However, it is not necessarily so that man is able to produce the highest FE at the lowest metabolic cost: the coordinative challenge of generating power while creating a rotation of the crank by extending the lower extremity may require additional, apparently ineffective, energy expenditure.

The Norwegian researchers propose instead a parameter called “dead centre size” (DC). They look at the two weakest parts of the pedal stroke — the top and bottom — and compare how much useful force you’re generating to the average useful force over the whole pedal stroke. A typical value is about 25%. The idea is that the better these “low points” in the stroke are, the smoother your overall stroke must be, so you’ll avoid wasting energy accelerating and decelerating and so on.

So they did a study with 21 competitive cyclists, using force-sensitive pedals and high-speed video and so on, and sure enough found that DC was much better at predicting the overall efficiency of the cyclists than FE. So what does this mean? Well, it’s consistent with the idea that you shouldn’t worry too much about trying to generate power on the upstroke, since that’s a hopeless task. Instead, focus on keeping the whole cycle smooth, not letting power dip too far at the top and bottom. One thing I couldn’t tell was whether it’s possible for anyone without a high-tech laboratory to get a measurement of DC, in order to see whether they’re improving their form over time. It would be pretty cool if local bike shops were able to offer the service.

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Do the health benefits of cycling outweigh the risks?

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My new Sweat Science columns are being published at www.outsideonline.com/sweatscience. Also check out my new book, THE EXPLORER'S GENE: Why We Seek Big Challenges, New Flavors, and the Blank Spots on the Map, published in March 2025.

- Alex Hutchinson (@sweatscience)

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In a Jockology column last summer, I described a few studies about how switching from car to bike for a commute affects your exposure to pollution:

Whether you’re better off inside or outside a vehicle seems to depend on the vehicle and location. A Danish study in 2001 measured pollution exposure while driving or biking along identical routes in Copenhagen. The air inside the cars was bad enough that, even taking into account that cyclists were taking longer and breathing more deeply, the drivers were worse off. On the other hand, an Irish study in 2007 found that the air on buses was worse than the air breathed by cyclists, but that the higher breathing rates led to greater total exposure for cyclists.

It’s one of those issues that might make you think twice about cycling through a busy downtown core to get to work — that, and the risk that you’ll be flattened by an impatient driver. There’s an interesting study that just appeared online in the journal Environmental Health Perspectives weighing the balance between cycling and driving in cities (the full text is freely available here). They make an interesting distinction between what’s good for society and what’s good for you:

Though society may benefit from a shift from private car use to bicycle use (e.g. because of reduced air pollution emission), for the shifting individual disadvantages may occur. While the individual may benefit from increased physical activity, at the same time he/she inhales more pollutants due to an increased breathing rate. The risks of getting involved in traffic accidents may increase as well as the severity of an accident.

To tackle this question, the researchers (from the University of Utrecht) crunch an enormous data set to determine what would happen if 500,000 people switch from car to bike for short trips in the Netherlands (though they argue that the conclusions are widely applicable in other countries). They use demographic information along with studies on air pollution, traffic safety and physical fitness to reach the following encouraging conclusions:

For the individuals who shift from car to bicycle, we estimated that beneficial effects of increased physical activity are substantially larger (3 – 14 months gained) than the potential mortality effect of increased inhaled air pollution doses (0.8 – 40 days lost) and the increase in traffic accidents (5 – 9 days lost). Societal benefits are even larger due to a modest reduction in air pollution and greenhouse gas emissions and traffic accidents.

One of the interesting points that emerges in their discussion of the pollution studies is how big a difference your route choice can make (which I also discussed in the Jockology article linked above). In fact, they cite one study that found “walking close to the kerb in London greatly increased personal exposure”!

(via USA Today and — once again! — Amby Burfoot)

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More bad news for cyclists on bone density

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My new Sweat Science columns are being published at www.outsideonline.com/sweatscience. Also check out my new book, THE EXPLORER'S GENE: Why We Seek Big Challenges, New Flavors, and the Blank Spots on the Map, published in March 2025.

- Alex Hutchinson (@sweatscience)

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A new study in the Journal of Strength and Conditioning Research follows up with a group of competitive masters cyclists seven years after the original study showing that they had abnormally low bone density. The cyclists now have an average age of 57, and 89.5% of them meet the criteria for osteopenia or osteoporosis. In comparison, only 61.1% of a group of matched controls meet the same criteria.

It’s still not entirely clear why cyclists seem to have poor bone density. Obviously cycling is a non-weight-bearing, non-impact activity, so they’re not getting any bone benefits from their time in the saddle. But it appears that their cycle training makes them less likely to do any weight-bearing activity even compared to non-athletic controls who don’t do any training at all. Another possibility is that they’re sweating out too much calcium, hindering bone formation and repair. This study doesn’t do much to clear up the mystery, but it does show that this is a real effect, not just an artifact of the general skinniness of cyclists — otherwise the equally skinny control group would show the same effects.

One important note: four of the 19 cyclists in the group started weight training during the seven-year interval, and they were able to slow their rate of bone loss. It’s another reminder to everyone whose main sports is something like cycling or swimming: you need to do something that stresses your bones, either through sharp impacts or the torque applied by strength training.

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“Heart rate recovery” and acute vs. chronic training fatigue

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My new Sweat Science columns are being published at www.outsideonline.com/sweatscience. Also check out my new book, THE EXPLORER'S GENE: Why We Seek Big Challenges, New Flavors, and the Blank Spots on the Map, published in March 2025.

- Alex Hutchinson (@sweatscience)

***

I had a chance to see an interesting study in progress a few days ago, during my visit to Cape Town, which prompted me to look up a paper that appeared earlier this year in the European Journal of Applied Physiology. It’s a case study of an elite Dutch cyclist being monitored with something called the Lamberts and Lambert Submaximal Cycle Test (LSCT), which was first described last year in a British Journal of Sports Medicine paper.

The gist is as follows: to warm up before a hard workout, you do a specific 15-minute protocol (6min at 60% of max heart rate, 6min at 80%, and 3min at 90%). You measure your power output and perceived exertion during these three stages, and then you measure how much your heart rate decreases during the 90 seconds after the test. Doing the test frequently (it’s not too strenuous, so you can do it as a warm-up before pretty much every workout) gives you objective data that tells you whether you’re fresh or tired, and whether your training is making you faster or slower.

Just as a sample, here’s a snippet of data, showing the power (at a fixed heart rate) for the first stage of the test, compared to the weekly training load. Pretty clear correlation:

lsctYou can see a gradual increase in power as the training cycle progresses, indicating that the cyclist is getting fitter. But you can also see big spikes in power during the heavy training weeks — that’s not because he was “fitter,” but because the acute training-induced fatigue meant he had to work harder (and thus produce more power) in order to get his heart rate up to 60% max. The mechanism has to do with decreased sympathetic nerve activity and increased parasympathetic nerve activity — and what’s most interesting to me is that the exact opposite happens in the case of chronic training-induced fatigue.

The same pattern can be seen in the heart rate recovery data:

lsct2During the heavy training weeks, the athlete’s heart dropped more quickly than during the other weeks. So he was tired from the dramatic increase in training load — but the test suggests that he was what the researchers call “functionally overreached” as opposed to “non-functionally overreached.” Had he persisted with the extreme training load for too long, his heart-rate recovery would have started to dip down instead of up, indicating overtraining. In other words, the researchers conclude:

This suggests that training-induced acute and chronic fatigue are reflected differently in the LSCT, which has important practical applications for monitoring.

Obviously this test is best suited to cycling, since you can precisely measure your power output. But I wonder whether a simplified version of the test, where you just exercise (run, row, whatever) at a set submaximal heart rate and then measure your heart rate recovery, would provide any meaningful information.

Oh yeah, the study I saw in progress: two groups of cyclists, each doing two (I think) hard workouts a week. One group does them on set days, come hell or high water; the other group does the LSCT three times a week, and determines whether or not to work out that day depending on the results. The hypothesis is that working out when your body is ready to go, and resting when it’s not, will lead to greater gains in fitness and performance. It’ll be interesting to see the results.