Saturday, August 25, 2012

Vuelta stage 8 VAM for final climb

I was a bit shocked to see Valverde (Valv-Piti) and his seeming best friend Rodriguez out-climb both Contador and Froome in stage 8 of the Vuelta. Was it that Valverde has raised his game to become a world class sustained climber, but only when racing in the safe confines of Spain? Or was it more that Froome and Contador weren't up to their best, allowing Valverde and Rodriguez to keep up?

The obvious check is the VAM: the rate at which they were able to gain altitude. It's roughly correlated to power/mass ratio. In the Armstrong era, it was typical during the Tour for Lance to be significantly over 1700 meters/hour for beyond-category climbs gaining over 1000 vertical meters. On short, punchy climbs riders were over 1800, even 1900.

For profile data, all I really used was the official route data from the organizers. These show the climb gains 580 meters in 7.2 km, an average grade of 8.1%. That's fairly steep and fairly short by Tour de France standards, well-suited to a high rate of vertical ascent.

For timing I used this video. It took 20:25 for the top riders to climb the final 7 km, where I started the timing immediately following the Sky train crossing the 7 km banner, and ended it with Valverde crossing the finish line with his arms in the air.

I didn't have an altitude number for 7 km to go, so I interpolated from the surrounding points, resulting in the estimation of 14 meters gained in the first 200 meters of the 7.2 km climb. This leaves 566 meters of climbing in the final 7 km.

The result... the VAM was approximately 1663 meters/hour.

Compare and contrast with Verbier in the 2009 Tour de France...

Using climbing times from The Science of Sport:

rider
time
VAM
Alberto Contador
20:36
1858
Andy Schleck
21:19
1796
Carlos Sastre
21:42
1764
Lance Armstrong
22:11
1726

So this isn't a return of Armstrong-Contador-era super-climbing, even by Contador himself. Valverde and Rodriguez are each riders with an enormous anaerobic work capacity (high short-term power). The longer the climb, the less important anaerobic capacity, and the more important aerobic capacity. So this climb is not necessarily indicative of Valverde's and Rodriguez's ability to stick with Froome and Contador on climbs like L'Alpe d'Huez, the Tuormalet, or Mount Ventoux, and even for those climbs, this VAM number would fall well below the Armstrong-Ullrich-Basso "glory days".

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