The bicycle computers with which almost all Tour cyclists ride, provide an enormous mountain of data. Mathieu van der Poel is exceptionally generous with sharing it on the popular cycling app Strava. His admirers know the powers he pedals, the speeds he develops, the number of times per minute his pedals turn and how his heart races. Heart rate: you can’t get much closer to a rider.
Yet it does not say much about Van der Poel’s well-being that he had a maximum heart rate of 194 in the cobblestone stage and an average of 144 per minute and on Sunday in the first mountain stage 178 and 135. The weather and the duration of a race play a role. For example, heat increases the heart rate. And even with a top rider like Van der Poel, his average heart rate goes down a bit in the third week. In this year’s Giro he went from 132 in stage 4 to 103 in stage 18.
Hobby cyclists who cycle roughly 150 kilometers for days in a row with a heart rate monitor have the same experience, only much earlier and stronger. After just a few days, their average heart rate is well below their ‘tipping point’. This roughly represents the heart rate above which the legs start to hurt. According to many, that point of acidification is fixed for everyone. But that’s the question. After three weeks of cycling through France, it will be quite painful to get close to that ‘lactate threshold’ heart rate.
‘Motorcycle’ in body
Cycle trainer Louis Delahaije pioneered lactate measurements and concluded that lactate thresholds and tipping points are nonsense. Riders often talk about the ‘motor’ in their body. According to Delahaije, heart rate is not representative to see how that engine runs. Lactate does.
If wattage says something about the power that the motor delivers, then lactate stands for how efficient that motor is. Crucial to know for the Tour, according to the trainer. A rider will not last three weeks with a fantastic engine that is not economically tuned.
Popularly, acidification starts when a rider produces more lactate than uses. What distinguishes a top cyclist from the rest is that he or she can postpone that moment endlessly through targeted training and can therefore cycle for a very long time at a very low lactate level. None of the riders Delahaije trained could do better than Steven Kruijswijk. “His motor never breaks down.” If the Tour de France would last not three but nine weeks, Kruijswijk would win every time.
Exceptional talent for durable work
Actually, the 35-year-old resident of Monaco was born about a hundred years too late. The 1922 Tour de France was 5,373 kilometers long with stages between 260 and 482 kilometers, he had won without a doubt. Provided he had discovered and trained his exceptional talent for endurance work, reflected in a lactate figure.
A century ago Kruijswijk could not have known that. Now it is: ride up a long col, prick the finger and wait ten seconds. At a score of 2.5 or, even better, 2 millimoles per liter of blood, a big smile appears: very low, very good.
For now, the lactate level is unsuitable for display on the screen on the racing wheel, but who knows. As soon as bicycle computers with a retractable needle appear on the market, we know that the data mountain will grow again.