According to many cycling followers, the core of the sport is not so much in the last 200 meters. They feel that cycling takes place while climbing in the mountains. There we see the suffering of the rider in its optima forma. Fighting against himself, the natural environment and his opponents. We look forward eagerly to the duel of the climbers when they conquer the high Alps and steep Pyrenean peaks in the upcoming Tour. And we ourselves want nothing more than to cycle in the mountains. But how hard do the best climbers ride uphill? When can a cyclist be called a climber? In other words, how does a climber reach the top?

Climber type among cyclists

Within cycling and mountain climbing, the category of climbers can be divided into different types and sizes. In particular, the race climber and the tempo climber are clearly distinguishable from each other. The race climber is often too light to do time trials. They can handle uphill tempo changes well and the race climber is tall and thin or just small. The tempo climber is often slightly taller, has difficulty with acceleration but has an excellent time trial uphill. Jan Ullrich is such a tempo climber. In this article, we will focus on the race climber and the tempo climber and everything in between.

Oxygen intake in mountain climbing

First, climbers naturally have extremely high maximum oxygen uptake (VO2max). Oxygen allows the body to burn fats and carbohydrates and thus release energy. Oxygen enters through the lungs and is transported through the blood to the muscles. The more oxygen an athlete can take in, the more he can burn and thus the harder he can cycle. Now, this VO2max is innate and only about 15% trainable. So this is what we call talent!

Note that the VO2max is expressed in kg/ml/min. So this is a relative measure, which provides perfect guidance for climbers since climbing is a battle with gravity and lightweights are thus at an advantage. However, a high VO2max does not guarantee a successful climbing career. Especially during the grand tours, where the highest cols must be conquered, how long you can sustain riding at submaximal levels is especially important. How long can a rider ride at 70%, 80% or 90% of his VO2max? Padilla and colleagues studied among 17 professional cyclists the impact of a big lap. Using heart rate and power data, he concluded that riders cycle only 1.0% to 2.3% above their anaerobic threshold during tough mountain stages.

Thus, a rider does not need to make much use of his VO2max. Fortunately for a climber, persistence at submax levels is trainable. Through intensive endurance training and interval training at the anaerobic threshold, the heart rate associated with the threshold will get closer to the maximum heart rate and the rider will be able to pedal more power at his threshold. The disadvantage of such training is that it can come at the expense of explosiveness. Sloping mountain stages with lots of altimeters can have a completely different outcome than a stage with only an uphill finish.

Muscle fiber types and pedaling frequency

To become a top climber, a rider will have to have the right ratio of muscle fiber types in addition to a high maximum oxygen uptake. Everyone possesses so-called slow-twitch type I and fast-twitch type II muscle fibers. Unlike a sprinter, a climber naturally possesses more type I fibers. As a result, although a climber cannot produce much power in a short time, because the type I fibers produce little lactate, he can maintain this power for an extremely long time. An additional advantage of the slow muscle fibers is that they take up little volume. This is why climbers are generally petite and lightly built. The problem the climber now faces is choosing the right pedaling frequency.As can be seen in the graph, the delivery of maximum power of the fast and slow muscle fibers depends on the contraction rate. Translating this contraction rate into the number of revolutions per minute, the slow muscle fibers are most efficient at a cadence of 60-70 RPM, while the fast muscle fibers deliver optimal power at a cadence of 130-140 RPM. Because the contribution of the fast muscle fibers is proportional to the increase in power, it can be said that for optimal efficiency, the cadence should be increased when more power is required.

A climber possesses more slow than fast muscle fibers and does not need to deliver extremely high power during a long climb. In the context of efficiency, he will therefore choose a relatively low pedaling frequency. But it is not that simple. Peak forces become higher as pedaling frequency decreases. Higher peak forces mean a greater contribution from the fast muscle fibers. Something a climber does not want. Opting for a higher pedaling frequency in that case results in lower peak forces, which in turn results in lower efficiency. So it's make or break for the climber.

Optimal weight for cycling and climbing

Perhaps the most obvious characteristic of a good climber is only now coming into play: weight. Climbing in the mountains is a battle against gravity within cycling, and therefore a light climber is by definition at an advantage when the road is uphill. However, a light rider can deliver less power than a tall rider (assuming they are both trained). Therefore, when riding up a climb, the focus is not so much on the absolute power the riders can deliver, but on the relative power.

This relative power output is expressed in Watts/kg. An interesting question now is: at what gradient is the light rider at an advantage? Imagine two pro riders: one is 75 kg and pedals 412.5 Watt at his tipping point (412.5/75 = 5.5 Watt/kg). He is clearly a tempo climber. His competitor the race climber is only 60 kg and pedals 360 watts at his tipping point (6.0 watts/kg). It is not hard to imagine that the tempo climber goes faster at low gradients and that the race climber gets to the top sooner when the road rises 12%. What is noticeable is that both riders are not much inferior to each other in terms of speed.

However, the differences are significant (by pro standards) when both men cycle for an hour at the tipping point. Here we have not taken into account the difference in frontal area and drag coefficient. Both of these variables fall in favor of the lighter rider. In addition, the tempo climber has another additional problem: he has to deliver absolutely more power than his lighter competitor during tough mountain stages. That means he consumes in more energy and his heat production is a lot higher. So a heavy rider has to drink a lot more and will have more trouble controlling his body temperature.

Top climbers within cycling

So what does it take within cycling - and specifically mountain climbing - to compete for a good result during a grand tour? And how much power do the top cyclists deliver during mountain climbing on the final col of a tough mountain stage? To find out, controversial doctor Michele Ferrari introduced the VAM. VAM stands for vertical speed in meters per hour. By dividing the altitude difference of a col by the time it takes the rider to cover this distance, you can compare the performance of riders on different cols. What is striking is that almost all of the achievements are older than 10 years.

Still, Contador leads the list with the climb to Verbier in the 2009 Tour. To put Contador's climb in perspective, he completed the 8.7 km in 20 minutes and 40 seconds. Rui Costa took 22 minutes and 23 seconds in the second stage of the Tour of Switzerland. Once the VAM is known, it is possible to estimate relative power. Using the formula Relative power = VAM / Gradient factor x 100, Contador produced 6.78 Watt/kg (!) in the climb to Verbier. By the way, the gradient factor is the steepness degree of the climb and ranges from 2.6 to 3.1, with 2.6 corresponding to an average gradient of 6% and 3.1 of 11%.

The steeper a climb is, the easier it is to achieve a high VAM. Because the speed is lower and therefore the influence of air resistance is smaller. Also notable is Indurain's performance. Far from being a race climber, due to his large stature, Indurain weighed about 80 kg during the 1995 Tour. To reach a VAM of 1758 m/h on the Alpe d'Huez, he averaged a relative power of 6.26 Watt/kg. This corresponds to an absolute power output of a whopping 500 Watts! Try keeping that up for 40 minutes.

Conclusion

To become a top climber within cycling and mountain climbing, you must possess some exceptional physical qualities. A relatively high maximum oxygen uptake combined with a large amount of slow muscle fibers is essential to ride hard uphill. If you can maintain a relative power of 6.0 Watt/kg on the longest cols during the Tour, you are a candidate for the podium. Unfortunately, that cannot be achieved with talent alone!