Carb consumption planning

Good afternoon all! Chris here, Loyal TR user and avid TR podcast-listener making my debut on the forum!

I fully expect this to have been a thread before but can anyone point me to a decent nutrition consumption calculator for cycling I.e. something you plug in distance/time/speed/power/body weight/climbing/other relevant metrics and to get a good indication of your nutrition requirements for the specified event

Thanks in advance!

:metal:t3:

60-90g of carbs per hour regardless of body weight.

Try putting this on your Garmin


or this if you have an Xert subscription as well as a TR one

Brendan, I was thinking something very similar to what you wrote, however sports nutrition recs are traditionally 30-60 grams per hour, as 1 grams per minute is supposedly close to the maximum absorbable rate from the human gut.

Now, I know Gebrselassie consumes 80-90 g per hour, but most of my clients start getting GI problems above 60g/hr. WHat’s your experience been? Do you tolerate higher amounts ok?

60g malto/glucose and 30g fructose are how you get to 90g/hour without GI issues. See this thread Generic / Fake Maurten? or look into the products by maurten and SIS beta fuel

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I appreciate all the replies so far but it makes me realise I worded my query wrong!

I’m really after trying to calculate the calorific demands of an event - I.e. if I want to ride X at Y speed, will I fuel at 60/hour or need to go higher at 90/h (thus needing to use an alternative strategy/product mix)

Chris

Chris, it’s all good advice above. Keep it simple!

I don’t know of such a precise calculator, but to try to answer your question we can do some simple calculations to work out how much you’re burning in kJ/hr or kcal/hr based on your power over time.

However, you’ll quickly realise that you can’t take fuel in at the same rate as you expend it…90g of carbohydrate per hour is ~360kcal per hour (1g of CHO has 17.2kJ or 4.1kcal energy content). You’re probably expending at least 500kcal/hr. If I average 167W for an hour, that’s ~600kcal (you can find the calculation here in the TR Blog).

Don’t forget you’ve got a plenty of fat stored up to use, not to mention ~400g of carbohydrates sitting in your liver and muscles waiting to be used up!

For longer rides, take in what you can stomach! You will need to experiment.

See also here in the blog: https://blog.trainerroad.com/are-you-eating-too-much-here-are-five-situations-you-might-be/

Good luck with your event!

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And this is why TR is THE BEST online community!!

Chris

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If you want to estimate your calorie consumption, this is how I go about it:

  • Plug your data (weight, ftp, …) and the GPX in to BestBikeSplit (you don’t need a paid subscription)
  • Run the race simulator, which will give you an estimated time as well as estimated average watts
  • Estimated Calories (=kcal) = (Avg watts * 3600 sec * estimated hours of your ride in decimal)/1000

Works pretty well for me and turns out to be rather accurate, providing you can interpret the provide time and watts from BestBikeSplit to identify if it matches numbers you could put out IRL.

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90g for sure; maybe they aren’t taking 2 different carb sources which are needed to hit 90? It need to be like malto and fructose.

30g is really low, definitely not enough fuel for anything 2.5h or beyond IMO.

I eat lots of carbs and my body is used to them for sure, so I haven’t had any digestion issues at 90 or even slightly higher.