In the last few years, nothing has gone through such an extreme evolution in the world of cycling as nutrition, specifically carbohydrate consumption. For as long as I have been an avid cyclist, the rule of thumb has been that 60-80 grams of carbs per hour is the ceiling of what the body can utilise.
But now, it is understood that the body is capable of utilising carbohydrates at far higher rates. Many pro riders are now taking in between 120-150 grams per hour, with some heading north of 180 grams.
On his way to winning Unbound 200 this year, Cam Jones shovelled in almost 200 grams per hour for the best part of nine hours. For Jones, the ability to consume this amount of fuel on the bike came naturally – more than can be said for most of us. But even for riders not winning the biggest bike races in the world, it does look like consuming more carbs on the bike is the key to improved performance.
As with anything intrinsically individual, following what others do is far from the best course of action. Particularly if the ones we’re following are pros.
This is where ExoAnalytics comes in. This British brand aims to objectively answer the question of how many carbs an athlete can actually utilise per hour. To find out exactly how it works, the science behind it, and my own personal results, I took part in the surprisingly simple home test.
This test is now available through the ExoAnalytics website for UK residents for £350.
How did we get here?
The age-old carb intake recommendations might be outdated, but they do have some scientific backing. We have to look back to the mid-90s to find the source of the 60-grams-per-hour guidance. The understanding was that the SGLT1 transporter (the mechanism used to carry glucose to our muscles) limited usable carb intake at 60 grams per hour.
It was then later understood that mixing carbohydrate sources could increase the rate of absorption, as fructose uses a different transporter (GLUT5) to make its way to the muscles. This raised the ceiling to 90 grams per hour, with the now fairly standard 2:1 glucose to fructose ratio allowing for greater carbohydrate utilisation.
More recently, tweaks to the ratio (around 1:0.8) bumped that total to roughly 108 grams per hour. In practice, most riders just aim for 110-120 grams. However, it would appear there is significant variability in the oxidation ceiling based on individual genetics. Some athletes can oxidise a maximum of around 30 grams per hour, while others can utilise six times that amount.
That wide range means that the general guidelines are far from useful, because carbohydrate usage is highly individual.
Who is this test for and why is carb oxidation useful?
As with most performance topics, there’s no one-size-fits-all approach, and the high-carb revolution comes with nuance. Simply consuming more carbs doesn’t always boost performance – sometimes it helps, sometimes you ingest more than the body can use, and sometimes it triggers GI issues that actually hinder performance.
Neilson Powless explained that he defaults to 120 grams of carbs per hour in most races, but has gone as high as 200 g/hour. Yet without knowing your personal oxidation rate, you might be underfueling or overfueling. One half of the ExoAnalytics team, Jamie Pugh, has seen athletes capable of oxidising 180 grams per hour who were leaving gains on the table simply because they didn’t know their limits.
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