The Physiology of Pro Cyclists – Massive Lungs

As an asthma sufferer, albeit one who hasn’t had many problems in the last 8 years or so, I recently had a routine check up at the local GP practice. Taking a peak expiratory flow test, I recorded a breath volume – essentially a derivative of lung capacity – about 1/3 below that of the average 18 year old of my height.

A peak expiratory flow (PEF) test is undertaken on a peak flow meter, with a sliding dial which moves further up the measurement tab the harder you blow. I remember from reading It’s Not About the Bike that Lance Armstrong went off the scale in a PEF test, blowing the dial to the very end of the meter despite having just finished his first session of chemo. Now I know what you’re all thinking, but however you look at it and whatever you think of the guy, Lance’s athletic credentials can’t be disputed. For reference, I got the dial up to about halfway.

Lance is by no means the only cyclist with extraordinary lungs. Miguel Indurain, for example, had a lung capacity measuring 8 litres, which is 30% larger than that of the average man. 30%! Larger lungs means you can simply breathe in more oxygen. More oxygen means more oxygenated blood, which in turn means more red blood cells. More red blood cells means a higher aerobic threshold. Any cyclist with a basic knowledge of a ramp test or a time trial knows what this means. Simply, you can ride faster for longer. Other methods of obtaining more red blood cells include altitude training, or taking performance enhancing drugs such as the red blood cell booster EPO, showing the natural advantage possessed by riders with enormous lungs. It’s hardly surprising that Big Mig was such a dominant rider.

This suggests that in the same way as Usain Bolt has an incredibly rich supply of fast twitch muscle fibres and Jenson Button has reaction and reflex times dwarfing those of standard people, the best cyclists are physiologically perfectly matched to the sport we love. The one downside to this discovery is that I now realise that my poor lung capacity renders me as unsuited to flying up mountains with Froome & co. as Dawn French is physically unsuited to the High Jump. Okay, maybe not quite that unsuited, but the point still stands. Whilst it is impossible to ignore that dedication and application are of fundamental importance in obtaining athletic success, that genetics play a massive part in selecting our sporting champions is also undisputable.