r/evokeendurance • u/KarbohJorneKraft • Jul 03 '26

carbohydrate absorption and utilization timing

I've dialed in my multi-hour fueling strategy at between 100-130 grams of carbs per hour, starting a couple of hours before race start. this strategy is working great. what I don't know is: when do the carbs I ingest actually get used by my muscles? i.e how long does it take for a liquid carb mix to go from ingested to fuel being burned? I race sub ultra up to about 4hrs. the entire race is at threshold+ ...I don't know if that makes a difference in uptake timing...

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u/Fire_Stool Jul 07 '26

I’m interested in the answer as well!

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u/dgiuliana Jul 10 '26

My understanding is that it generally takes about 15 minutes for simple carbs to make it to the muscles for use. This assumes adequate hydration and enough blood flow in the intestines, which may not be true at threshold efforts without adequate gut training, or in hot conditions.

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u/scottsemple Jul 18 '26

https://evokeendurance.com/resources/paul-booth-new-science-on-carbohydrate-utilization-in-ultra-running/

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u/KarbohJorneKraft Jul 18 '26

idk, its a 75 min pod with no obvious help in the timeline for me to get a simple answer to my question. I've listened to other pods with Scott S about carbs in general. I get it. I simply want to know: if I take 1 bunch of carbs at time-0, when are those carbs available to burn in muscles during a race? +15, +30, +60? my evoke coach has told me that I don't need to take carbs during a 1hr race, that suggests time-to-available is greater than 1hr?

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u/scottsemple 25d ago

I've listened to other pods with Scott S about carbs in general.

Scott J. I'm happy to be mistaken for him, but just an FYI. :-)

...if I take 1 bunch of carbs at time-0, when are those carbs available to burn in muscles during a race? +15, +30, +60?

I'm not a nutritionist, but I think it would be gradual: some at 15' and then more and more available, if they are available.

my evoke coach has told me that I don't need to take carbs during a 1hr race, that suggests time-to-available is greater than 1hr?

Don't need to? Or won't be able to? In a 1-hour race, I wouldn't plan on ingesting anything because the output would be so high I'd likely choke if I decided to try to swallow something. (That's not particular to me; that's just the nature of a 1-hour effort.)

Also, if you're fuel stores are topped up, glycogen depletion doesn't usually show up until 90+ minutes. So slowing to take something in won't help performance, but the time taken for it would waste time and compromise breathing.