Calculating carbs per hour

nerraw1111

What is the best means of calculating how much carbs you should be taking per hour of exercise?

I’ve read numerous formulas which are usually contradicted by another report which is then contradicted, and so on.

Also, is there a difference of how those carbs are taken? EG: Gels/drinks/real food?

I've taken gels etc before but usually on feel. It worked most of the time until earlier this year when I pretty much bonked towards the end of a race.

Gringo78

what type of exercise are we talking about? Its going to be different for runniing, swimming, cycling etc.

You're basically looking to know the number of calories burned per minute and then what porportion is being utlised by Fat and Glycogen - you have unlimited stores of fat (relatively speaking) so you're looking to replace only the amount of calories from Glycogen burned.

For running there are formulas which calculate the calories burned per minute as something from 15-20 cal/min, depending on the intensity of the run (you average heart rate). However, the fat/glycogen split depends on your efficiency as a runner, how well trained you are, your training at slower paces to utilise fat burning. Its guesswork, split could be 50/50, it could be 90/10. I think at marathon pace its typically 60-70% of the calorie burn is coming from glycogen.

So calculate how much calories are burned from glycogen, calculate how much you need to replace and then take enough carbs. As regards what carbs, the more intense the exercise, the harder it is on your digestive system to process food hence the preference for the likes of gels & liquids. Whatever your system can tolerate. Rememeber you start with maybe >1800 calories glycogen reserves (again, this is a guesswork figure, varies person to person) so you just need to take on enough to ensure you don't run that reserve too low. Once you run out of glycogen you are down to running on fat which will mean you will be reduced to moving at very low intensity.

nerraw1111

Cheers Gringo. That helps a lot.
It’s mainly for multisport races, the likes of Gaelforce and Roar, lasting around 4 or 5 hours. I was reading that 60 grams of carb is roughly what is needed.

Gringo78

nerraw1111 wrote: »

Cheers Gringo. That helps a lot.
It’s mainly for multisport races, the likes of Gaelforce and Roar, lasting around 4 or 5 hours. I was reading that 60 grams of carb is roughly what is needed.

If you're talking about events over 3-4 hours then its a case of get in as much as you can tolerate. 60g of carbs per hour is pushing 3 gels per hour which a lot of people will find hard to stomach - Key is to start early getting the carbs on board, basically right from the get go - kick things off with a gel 5min before the start.

Man_bear_pig

You'll need to load up on carbs the night before and again that morning. Make sure you're comfortable eating that much and don't try it for the first time on race day. otherwise you're body wont know what hit you.

Afterwards you'll need a good 4:1 or 5:1 carbs to protein ratio to recover as efficiently as possible.

When's the race on?

robinph

Here's a table of calories per hour for different activity levels:

http://www.nutristrategy.com/caloriesburnedrunning.htm

Not sure why they are showing XC running as being so low? Whoever they were testing clearly wasn't trying hard enough at the time.

tunney

Gringo78 wrote: »

If you're talking about events over 3-4 hours then its a case of get in as much as you can tolerate. 60g of carbs per hour is pushing 3 gels per hour which a lot of people will find hard to stomach - Key is to start early getting the carbs on board, basically right from the get go - kick things off with a gel 5min before the start.

The maximum most can absorb is around 240-320kcal an hour or 60-80g carbs an hour. There is a difference between tolerate and absorb.

Man_bear_pig wrote: »

You'll need to load up on carbs the night before and again that morning. Make sure you're comfortable eating that much and don't try it for the first time on race day. otherwise you're body wont know what hit you.

Ah the famous carb loading. Most people heard of carb loading and then think "oh eat lots". Then they wonder why they are bloated, sluggish and lethargic.

The body stores alot more glycogen than people give it credit for and the body uses fat and CHO to fuel itself. Carb loading, as implemented by most, is a terrible idea. Read research get a good protocol, test it and then use it. Don't just eat more.

corny

tunney wrote: »

Carb loading, as implemented by most, is a terrible idea. Read research get a good protocol, test it and then use it. Don't just eat more.

I actually read its far less effective for women believe it or not.