> could absorb and burn 100 calories per hour

burning a hundred calories an hour is trivial. Most people will burn 100 calories per mile when walking or running, and more if moving as fast as these athletes, and many, many humans can do this for far, far longer than 2 hours.

It's the absorbtion that's the challenge. Maurten is not somehow alone in the particular stuff they've developed - ultra runners are generally shifting up into the 90-120 gram/hr range (or beyond!), using a variety of different companies' products. The gut training protocols for this are widely discussed in the world of running for almost any distance above a half marathon.

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loeg 7 hours ago | parent | next [-]

> burning a hundred calories

GP left out the units but is clearly talking about grams ("absorb ... 100 carbs per hour"), not calories (no one needs training to absorb 25g/hr). Carbs are 4 kcal/g. 100g of carb (400 kcal) an hour isn't replacement level for even casual athletic efforts, but it does mitigate the loss of glycogen in muscle somewhat.

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wging 5 hours ago | parent | prev | next [-]

I've read that even if you absorb it all, there's some question about whether it's useful. This Alex Hutchinson article suggests, among other things, that it may spare your fat stores rather than your muscle glycogen:

> Even if you can absorb 120 grams per hour, it might not make you faster. In Podlogar’s study, cyclists burned more exogenous carbs when they consumed 120 rather than 90 grams per hour, but that didn’t reduce their rate of endogenous carb-burning—that is, they were still depleting the glycogen stores in their muscles just as quickly.

https://www.outsideonline.com/health/training-performance/en...

https://archive.ph/Vpk0h

https://pmc.ncbi.nlm.nih.gov/articles/PMC9560939/

	▲	loeg 2 hours ago \| parent [-]
		That may still be worthwhile if fat is harder to recruit than exogenous carbs.

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bethekind 6 hours ago | parent | prev | next [-]

Where does discussion on gut training occur? All I know is you need a 5:4 ratio of glucose to fructose? Then when you train, you use the gels and the more you do it, the more capable your gut gets at absorbing without distress.

Is that all the science to it?

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chongli 6 hours ago | parent | prev [-]

Wow so he was absorbing 400 calories per hour with this gel, but he was likely burning 3-4x that amount (or even more) while running 13.1 miles per hour!

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brianwawok 6 hours ago | parent | next [-]

In a two hour race that’s still 800 bonus calories, that’s something.

The race to tolerate lots of carbs is usually something you think of in 8 hour Ironmans. The good part is you can do most of it on the bike, which is much easier to eat as you go. As far as I know, many elite runners were doing like 50% water, 50% sports drink and consuming way under 100g.

	▲	PaulDavisThe1st 5 hours ago \| parent [-]
		> As far as I know, many elite runners were doing like 50% water, 50% sports drink and consuming way under 100g. This used to be true, and is still true for many athletes up the marathon distance. Above that, however, the momentum has swung heavily to very high carb intake. Most (though not all) of the world's best ultra runners (we're talking 7:00 min/mile pace through mountainous terrain) are picking this up, with many getting to and beyond 100g/hr of carb consumption.

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almost_usual 6 hours ago | parent | prev [-]

Your body stores roughly 2000 calories in glycogen. They are burning calories but nowhere near the amount a middle pack would be at this pace.

So ~2800 calories of carbs with some fat being burned.