When we think of Tour de France pros, we generally think endurance, aerobic efforts and lactate threshold, but equally important is their ability to deliver short, intense efforts when required. Two elements are involved here:
- anaerobic power (the amount of power delivered via anaerobic metabolism 1-120s)
- repeatability of this anaerobic power (the ability to repeat anaerobic efforts e.g. how many can you deliver and recover from) – we will look at this in a future post for this years Tour.
Stage 3 of this years Tour de France finished with a punchy 1km climb, requiring a significant amount of anaerobic work. 30-120s intense efforts use the glycolytic system (the fuel here is blood glucose or muscle glycogen. Note: for short hard efforts of 10s or less, the phosphagen system is used). When oxygen is not supplied fast enough to the muscles, we have anaerobic glycolysis. This results in the build up of hydrogen ions (raising muscle ph – or becoming more acidic). This spells the end of these short, hard efforts as the muscles rapidly fatigue. Anaerobic glycolysis is also a lot less efficient than aerobic glycolysis and rapidly reduces muscle glycogen.
As with any duration of effort in pro tour riders, there will be riders who have good absolute power (larger, strong riders e.g. classics specialists like Cancellara) and those with good power to weight (climbers such as Rodriguez). Both deliver phenomenal power over periods of 30-120s, but in different ways. Cancellara may well deliver 700-1200w (8.5 – 15w/kg) for 30-120s, while Rodriguez is likely in the range of 550-900w (10-16w/kg), but is a lot lighter and therefore goes uphill like a rocket. So it’s horses for courses with Rodriguez or Cancellara not likely to even be able to hold the others wheel on their rivals specialist terrain.
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