The 10 grams of carbs an hour claim falls apart
A tiny carb dose looked good for about a day, then the man who posted it conceded the point.
Ten grams of carbohydrate an hour had a very short run as an endurance fueling idea.
Brady Holmer posted the case for it first. A study, he wrote, found that just 10 grams of carbohydrate per hour, a fraction of what endurance guidelines recommend, beats a placebo. In athletes adapted to either a very-low-carb or a high-carb diet, that dose stopped blood sugar from crashing and extended time to exhaustion by 22 percent. For anyone who has ever choked down six gels in a marathon, that is a tempting number.
Javier Gonzalez was not buying it. He posted that some have argued 10 grams of carbohydrate an hour is enough to prevent hypoglycaemia (blood sugar dropping low enough to hurt performance) during exercise, and that the latest data from @HenryJMartyn and @JamesyMorton clearly disprove this. That exchange is covered in more detail earlier.
Holmer did not fight it. His follow-up post was four words long.
Bad day to be 10 grams
"Bad day to be 10 grams of carbs," he wrote. Later in the week he posted "Good week to be a carb," which is about as clear a summary of where the argument landed as you will get.
The interesting part is what Holmer moved on to. He wrote that he does not care how 80 to 120 grams an hour of carbs improves endurance performance, then admitted he does. His point is that it is pretty clearly not just because you burn more of them, since there is probably a cap on how much you can burn. The brain is involved too. In his words, it is all energy using and energy sensing.
What it actually means
Nobody has shown that 10 grams an hour is useless. Holmer's post described a real result against a placebo, which is a low bar, not against a proper race-day dose. What Gonzalez knocked down was the absolute version of the claim, the idea that 10 grams an hour is sufficient to keep blood sugar from dropping. As he put it, absolute statements only need a single observation to be disproved.
Absolute statements only need a single observation to be disproved.
So if you were hoping this gave you permission to carry one gel for a marathon, it does not. The high intake research keeps pointing the other way, and the people arguing about it in public this week are arguing about why 80 to 120 grams an hour works, not whether it does.
Bad day to be 10 grams of carbs.
It’s all energy using and energy sensing.
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