• Boris Clark

Why Alaphilippe won’t win the tour: An analysis using (very) theoretical metabolic data modelling

Updated: Jul 26, 2019

Julian Alaphilippe may have a 1:35 minute lead in the tour de france as I write this, along with a couple of stage wins, one even in a TT, but based on my analysis of his (estimated) physiology, and the terrain to come, he won’t win this Tour de France, and I feel he won’t even make the top 5. Let me explain why.

Whats needed?

To win the Tour de France one needs to be able to sustain 6-6.5 watts per kg (w/kg) on the long climbs of the tour and in the TT. The higher values quoted here probably come from the early 2000’s era where things were perhaps a little less ‘natural’ than now, however, 6.25w/kg is still a very realistic estimate for a tour winner going full gas up a long climb. Not only do they need to do this on the final climb, but they need to do it repeatedly on several climbs, day after day. So what physiology does it take to do this.

Froome’s example

First lets model a known tour winner, Chris Froome, with known data from his testing at the GlaxoSmithKline Human Performance Lab. Froome has a VO2max of 5.91L/min, or 88ml/min/kg at his often quoted 67kg weight, and a maximum lactate production rate of 0.3mmol/s, and gross efficiency of 23%, meaning of the total energy he expends, 23% is ending up as power delivered to power the bike forward. At 4mmol of lactate (commonly around threshold), Froome had a power output of 419w, or 6.25w/kg as mentioned earlier.

Creating a virtual Alaphilippe

We don’t have this data on Alaphilippe, so we need to create a ‘virtual Alaphilippe’. Froomes VO2max is astonishingly high, so lets give Alaphilippe the best fighting chance we can and go for the same 88ml/min/kg as Froome, adjusted for his 62kg weight this equals 5.45L/min. We know that Alaphilippe is a very explosive rider, even able to out-sprint Peter Sagan at times. To do this requires high levels of anaerobic glycolysis, which means a high maximum lactate production rate of at least 0.5mmol/s I would estimate, but lets say he’s less explosive for the tour and this is down to 0.4mmol/s for arguments sake, and I’d suggest to do what he did with his punchy attacks in the first week it must almost certainly be more. This would place his power at lactate threshold around 375-380w at best, or 6.1w/kg. This is based on gross efficiency of 23%, so let’s say Alaphilippe is better than Froome in this area (who is already very high), and has gross efficiency of 23.5%. At 23% and 380w he had a metabolic rate of 1652w, so with 23.5% of the metabolic rate actually turning into power at the pedal his threshold would be 388w, then we reach the magical 6.25w/kg like Froome had.

Alaphilippe has impressed so far this tour, but the toughest challenges are yet to come

However, the higher lactate production rate of Alaphilippe plays against him when there is multiple long climbs on a stage. Sure for a single climb this allows him to be explosive, but when multiple long climbs are involved this ends up inducing higher carbohydrate usage, greater lactate production at all intensities, and overall faster fatigue.

But how did he win the TT and extend his grip on yellow on stage 14 up the Tourmalet? The TT was short by tour standards, and involved some short, and even punchy climbs, which would suit the physiology of Alaphilippe, and the Stage to the Tourmalet was only 117km and contained only 2 climbs. A far cry from the final week in the Alps. We’ve shown that in the absolute best case scenario (unlikely!) he can make the same power, but how that power is composed is quite different to how Froome’s is.

The time trial win was unexpected. But a single sharp effort does suit the characteristics of Alaphilippe.

The Alps

There are 3 mountain stages in the Alps. While two of the stages are quite short, one is 200km, and there is much time spent above 2000m altitude. A high lactate production rate and the lower total volume VO2max play against Alaphilippe in this scenario. Combined with the fact every extra day of riding with his physiology will take more out of his reserves than someone with a physiology more like Froome.

Our Prediction

We know Alaphilippe is motivated and willing to suffer, but this will be his undoing. I feel the long climbs, and high altitude will be too much for him to sustain. He will blow completely and won’t finish in the top 5.

So who will win?

It’s a tough one, I’d be inclined to say Bernal. He’s riding well, has an out of this world VO2max (over 90ml/min/kg!) and for sure a lower lactate production rate than Alaphilippe, plus the altitude won’t phase him at all. Team tactics, and how he may be called in to work for a faltering Thomas, who is still better placed on GC currently may play against him. Thomas has the pedigree, but hasn’t shown the same form this tour as 2018, Kruijswijk has looked strong, but hasn’t really made any moves yet, and couldn’t follow Pinot when he attacked in the Pyrenees. Pinot of course is riding exceptionally well too, but I feel he will suffer on the long, high altitude climbs of the Alps.

In short it’s an open race still, and no amount of numbers or modelling will ever predict the outcome fully. So now that I’ve taken some of the passion and panache out of one of the best tours in years and replaced it with science, let’s get back to the beauty and unknown and enjoy the final week, where anything could happen. Perhaps Alaphilippe could even prove me to be wrong, defy the odds, and wear a yellow jersey in Paris.