I’ve heard a couple of times recently that the current grand tour riders are faster because they eat more carbs during the race. I was dubious that it could make much difference. So I did a calculation .
Before show my calculations let’s just a put a few things out there. I’m interested in a debate. If I’m missing stuff or wrong then chip in, I’m here to learn. Oh and I don’t know if the current pros are doping.
Let’s imagine a 4 hour stage. I think the new energy products are increasing fueling rates from 60g of carbohydrates per hour to say 90g.
So over 4 hours at 4x30 that’s an extra 120g of carbohydrate taken in during the stage.
A gram of carbohydrate gives 17,000 J of energy
So our rider has taken on an extra 120x17,000=2,040,000 joules of energy
The stage is 4x60x60=14,400 seconds long
So each second the extra energy is 2040000/14400=141 joules. A joule per second is a watt. So the rider is taking in fuel at a rate of about 140W higher than they were before the hi carb thing came along
A quick google suggests our bodies are about 25% efficient so that 140W input is about 35W of output.
I have to say that seems like a lot. I assumed I’d prove that the extra carbs thing was rubbish. Even if I’ve over estimated in a few places 10w extra over 4 hours would make a difference. Particularly as it wouldn’t be over the 4 hours. You might only use that extra energy over an hour at the end of the stage. That’s an extra 40w and that could make a real difference
Oh and I’m an arm chair pundit. No sports science background. I don’t own a power meter. I’m very slow
more carbs does not = more power per se. Fueling correctly will allow better endurance.
Energy from food is measured by burning it. That isn't the same as energy in the body.
Anything new someone’s been spouting about procycling is a cover story to explain performance jumps without mentioning the drugs which provide the performance jumps.
In the perfect world, I would hazard a guess that riders want to have optimised the development of all their energy systems prior to a race, so train (arguably) with optimum but not too many carbs, whatever that looks like, then compete with more than adequate carbs. Fat burning is optimised for the race and carbs aren’t limited. It’s obviously a lot more complex than that, and also needs to factor in recovery etc, but it’s been discussed by quite a few physiologists over the last few years and pops up on Twitter quite a lot too with more informed opinions than mine. 🙂
I read the same thing.
I have to say, my immediate reaction was, 'This feels an awful lot like when they were telling us pro riders were getting faster because they learned that spinning rather than grinding cleared lactic acid build up more efficiently...'
I mean, it was kind of true, but they left out the part EPO and blood doping also played in this process.
