It’s the 2nd part of a series of two about the science behind Le Tour de France. Part 1 is available here.
After 1,916 kilometers in the 2010 Tour de France, we’re starting to watch some of the most popular riders climb up to the very top of the list.
The first 11 stages of the race were plagued by several terrible crashes that forced riders like Alexandre Vinokourov as well as Jurgen Van den Broeck to quit the race.
Champion and favorite in the overall title, Alberto Contador, is just four minutes ahead of Thomas Voeckler, who is the leader and appears to be suffering from an injury to his knee.
Other favorites to win the yellow shirt – such as Andy Schleck, Ivan Basso, and Australian’s Cadel Evans are all out of trouble. They are expected to be in a good position for the final half of the competition.
Amazingly, Johnny Hoogerland continued riding after being thrown through barbed wire.
Moving forward and upward
The initial portion of the event was defined by flat stages and a couple of short climbs, but the second part was entirely about mountains. Actually, the last 10 stages of the race are going to see athletes go into each of the Pyrenees and the Alps and compete on a total of six mountain high-mountain stages.
Although the flat stages focus on getting rid of wind resistance, the biggest obstacle for riders on the mountains ( tonight’s set included) is gravity.
Gravity is a downward-oriented force that is proportional to the weight of the object at issue. In this instance, the cyclist and their bicycle.
In the end, heavier riders must apply more force and generate greater energy (measured as watts) than those who are lighter during the climbs.
(Unfortunately for them, the benefit they’ll gain during descents won’t be as significant.)
When climbing, the most skilled climbers achieve over six watts per kilo of body mass. This is around 420 watts for climbers who weigh 70 kg. To put this in some perspective, the average cyclist can generate about 200 watts when climbing at an acceptable level.
One of the shorter climbs in stage 9 of the Tour de France. EPA/Guillaume Horcajuelo
From a physiological point of view, the top climbers maintain intensity levels at or near 90% of the maximal endurance when climbing.
Maximal aerobic capacity (also called the VO2 max) is the highest amount of oxygen that an athlete can use at the moment in time. It is expressed in the form of mLO2/kg/min (number in milliliters per kilogram bodyweight in a minute).
Specialists in climbing, like Andy Schleck and Alberto Contador, have a blood flow rate of 80 mL/kg in comparison to 40 mLO2/min/kg of people who are sedentary.
(Don’t) follow the leader.
When the stage is in the mountains during the high mountain stages, the top contenders to win the yellow jersey have their team members guide the peloton. These teammates – known as domestics – will ride at a speed that is designed to force other yellow-jersey-contenders into the “red zone.”
A cyclist’s “red zone” starts at his “lactate threshold“ – the intensity of exercise above where lactic acid begins to build up in muscles, leading to an intense burning sensation and, eventually, fatigue.
If the pace of riders in leading the pack isn’t adequate, the riders competing to win the yellow and polka dots jerseys (for the overall leader and the best climber or best climber, respectively) or even the stage victory could split off.
To break free, these riders take the position of standing on their bicycles so they can make use of the mass of their body to provide additional force to the pedals.