Monday, April 22, 2013

Getting Lean - A Guide to Being a Skinny Cyclist

As a competitive cyclist, whether it be on the road or off-road, there is a huge benefit in minimising your body weight.
The basic theory goes something like this:

If you need to race up hills, then Science tells us that the most important metric for your performance is the ratio of your power output to your overall weight.

Now, I know what you're thinking – Science has told us many things, like it’s unhealthy to just live on chocolate (that’s no fun) or that you won’t be able to get a rational expression for Pi (years of painstakingly tedious arithmetic down the drain), so why would you even want to listen to what Science has to say? Well, despite the many negative things that Science tells us, there are also a few good things too, like the fact that smoking gives you cancer (useful for saving money that would otherwise be spent on cigarettes) or that dogs sent in to orbit burn-up on re-entry (useful for saving dogs that would otherwise have been sent in to space).

Russian dog Laika was the first canine to be successfully (??) sent in to orbit (she died within hours of takeoff), however none of the boffins in the science department figured out a way to get her home safely.
Maximising the ratio of your Power Output divided by your Total Weight gives you the best chance of being able to race up a hill quickly. As it turns out, generally the easiest way to maximise this ratio is to reduce your total weight.

For example, an 80kg cyclist generating 400W threshold power has a Power to Weight Ratio of 5W/kg. If they drop down to 75kg and maintain the same power, this ratio increases to 5.3W/kg. The resulting increase in the Power to Weight Ratio (about 7%) is much easier to achieve than if the same cyclist was to maintain their weight at 80kg and then attempt to increase their threshold power (which would need to increase to around 427W).

So with this is mind, the most efficient way to minimise your weight (as a cyclist) is to shed body fat, keep all the useful power-generating muscle in your legs and have a super-skinny upper body that needs to be capable of nothing more than keeping your head at the correct angle to observe the road or trail ahead of you and take in nutrition (mainly in the form of low-fat water).

This explains why professional cyclists are so careful about their diet and so obsessive about their body fat percentage. It also explains why many aspire to achieve a body image that most people would generally view as unhealthy.

While this body image would normally be considered unhealthy and unattractive, it can help to provide a steady stream of podium girls.

Although, at the other end of the fitness-body-image-spectrum things can also start to look quite unnatural:
Power to Weight Ratio is less of a concern for track sprinters.

Obviously there are positives and negatives to the kind of extreme body type that climbing cyclists aspire to. While the ultra-skinny upper body helps minimise overall weight it also puts your collarbones at extreme risk of fracture resulting from a crash on the bike or just an overly aggressive handshake (this is why most road cyclists prefer to bow to one another).

While it’s generally quite healthy to keep your body fat low, it can also drop too far to a point where health can be compromised.

So, how do you know when you’ve pushed the limits of low body fat too far? One clear sign is a weakened immune system that has you catching a cold every time you feel a cool breeze. The other sign is when flies start using your leg veins as a trail map.

Another fun Science fact: Although GPS navigation is widely used today, many insects still prefer to use traditional maps.

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