Trying to work out how much I should be eating/drinking every hour on the bike as don’t think I do enough.
Anyone know how much carbohydrate the body is able to process each hour?
Thanks,
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Anyone know how much carbohydrate your body can process in an hour?
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Posted 1 year ago #
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1g per lean kg of bodyweight per hr, rougly
Posted 1 year ago # -
Isn't it roughly your weight in KG but in grams of carbs, e.g. 80kg bloke could use 80g of carbs per hour moderate exercise.
Might be wrong, shoot me down if so
Posted 1 year ago # -
about 6 pints
Posted 1 year ago # -
Guess the exact answer would be specific to a person as all our bodies are in different states of fitness etc.
For a general answer maybe the generic guides on carbo drinks could be of use? i.e. 750ml of energy drink per hour.
As always lots of info on the interweb, Mr G brought this up for me: Carbs info
Posted 1 year ago # -
For shorter rides (a couple of hours), you'll be fine without anything.
For longer rides, it's the 1g of carbs per 1kg of lean body weight. You're fueling your muscles, not your fat! In practice, this is very difficult to achieve.
Be honest with yourself too. If you go for a 3 hour bimble, where a lot of it is standing around chatting to your mates, you don't need to chug down a load of energy drink and cakes.
Posted 1 year ago # -
Having just had a full breakfast at Tesco I'll let you know once I can move again!
The winner of the vets category at the Montane Kielder 100 was consuming enery mix in his drinks, 3x gels and 2 (?) energy bars per hour.
Posted 1 year ago # -
people seem to be mixing up 2 things:
a) the rate at which you can digest carbs
b) the rate you can use the energywhere in fact b) can be way bigger and eventually you run out of resources and bonk. The figures I've seen both for digestion and fat metabolism (both around 300 Kcal/h) are quite low, and pose an absolute limit for long term sustained output once you've exhausted the limited glycogen your body stores for instant use.
Posted 1 year ago # -
Thanks all.
So based on 68g per hour, on last weeks road ride I should have consumed around 290g.
I actually consumed 225g. Doesn't seem like too much short of target but actually equates to 1 energy bar + 1 gel.
Posted 1 year ago # -
The figures I've seen both for digestion and fat metabolism (both around 300 Kcal/h) are quite low, and pose an absolute limit for long term sustained output once you've exhausted the limited glycogen your body stores for instant use.
600kcal an hour is about how much high intensity cycling burns, IIRC. So 300 + 300 sounds ok
Posted 1 year ago # -
(All this is IIRC.)
The 1g per kg per hour is for ensuring you end a ride refueled, so is important if you have to do the same again the next day. In practice, for most people, this isn't going to be the case, so you are fine to go into 'debt' during the ride and to refuel at the end.
Posted 1 year ago # -
been lots of this info of late in the printed stw mag think from mem that stated 7g of carb per 10kg of body weight per hour as a rough guide?
Posted 1 year ago # -
600kcal an hour is about how much high intensity cycling burns, IIRC. So 300 + 300 sounds ok
that's 600000 * 4.2 Joules in 3600 seconds = 700 Watts, and given 25% muscular efficiency (which is probably a high figure) that's 175W mechanical power, which isn't much!
Posted 1 year ago # -
Sleepmonsters Guide - good as always
I have also read but sadly can't recall the link that in any endurance event there is a finite amout of enery you can onload/utilise and you will never be able to replace all the calories used during sustained activity. This is mentioned obliquely in the above link.
The aim of mid actvity fueling is to minimise how much you dip into the bodies reserves by catabolsim of the muscles which over time will naturally impair performance. So post activity nutrition is of paramount importance, mid activity is minimising the harm.
Posted 1 year ago # -
An endocrinologist mate who specialises in treating diabetics reckons that your pancreas is designed to produce enough insulin to deal with about 80g of carbs a day. Others say its less.
His theory goes like this:
Some of your energy will and should come from fats you consume too. Just using carbs for energy in the short term is OK but long term you should look at providing some of your fuel from fat otherwise you run the risk of knackering your pancreas and getting diabetes. Only small percentage of people get diabetes but basically obesity related diabeties comes from the fact that fat peeps eat loads of carbs (thats what he thinks, I am in know way knowledgable about this)...
Posted 1 year ago # -
to deal with about 80g of carbs a day
don't you mean 800g ? 80gm isn't even one slice of bread... if your figure was right we'd all be dead.
Posted 1 year ago # -
simonfbarnes - Member
.to deal with about 80g of carbs a day
don't you mean 800g ? 80gm isn't even one slice of bread... if your figure was right we'd all be dead
Slice of bread is about 10-15 grams of carb.
Here it says 12 grams of carbs in bread so your body deals with about 8 slices a day, that's quite a lot of bread really.
Also it has been proven by many people in many races that you can live without any carbs what so ever, so dying from lack of carbs is a bit of a myth.
12000 years ago we didn't eat many carbs at all, we didn't have agriculture so no bread or pasta and not many spuds. Now I'm no expert on evolution but 12000 years isn't long enough for a major rearrangement of our systems such that you could convince me that we have evolved to eat 800g of carbs a day.
Now I don't advocate atkins or no carbohydrates but a bit of thinking tells you that we probably too many carbs.
Anyway my Dr mate mentioned previously has been working with the British Diabetic society researching lower carb diets for diabetics and guess what, loads of them (only a certain type cant remember which one) have gone insulin free. They get all their energy from fats and protein.
It makes me laugh when people say that eating fat makes you fat.
How do you make a cow or chicken fat? You feed them grain.Posted 1 year ago # -
Toys19, even Cordain & Friel in the paleo diet for athletes book advocate some carbs pre, during & post exercise for optimal performance & recovery.
Being as good an athlete as possible isn't the same thing as being as healthy as possible though, and since i won't be winning any races any time soon i too err on the low carb side of things.
Posted 1 year ago # -
finbar - Member
Toys19, even Cordain & Friel in the paleo diet for athletes book advocate some carbs pre, during & post exercise for optimal performance & recovery.
Being as good an athlete as possible isn't the same thing as being as healthy as possible though, and since i won't be winning any races any time soon i too err on the low carb side of things.
I agree entirely. Like I said I don't advocate no carbs, there are lots of carbs in fruit and veg you know..
Posted 1 year ago # -
In one Ranulph Fiennes' books he reckons that you can only take in about 10,000 calories worth per day however much you eat. He used up about 13,000 per day so he was a bit thin at the end.
Think that's total rather than just from carbs though.
Posted 1 year ago # -
Yep, i tend to go for sweet potatoes and ocassionally rice - i've been wheat-free for a while now and i feel much better for it.
Posted 1 year ago # -
simonfbarnes - Member
people seem to be mixing up 2 things:
a) the rate at which you can digest carbs
b) the rate you can use the energywhere in fact b) can be way bigger and eventually you run out of resources and bonk. The figures I've seen both for digestion and fat metabolism (both around 300 Kcal/h) are quite low, and pose an absolute limit for long term sustained output once you've exhausted the limited glycogen your body stores for instant use.
How does this stack up agains folk doing long time trials etc?
Posted 1 year ago # -
so dying from lack of carbs is a bit of a myth.
I meant dying from too much
Slice of bread is about 10-15 grams of carb.
Not the way I slice it - I get about 10 slices out of an 800gm loaf!
Posted 1 year ago # -
I meant dying from too much
Fair enough! What he means is that although your pancreas can make more, overworking it makes it break. So 80g is the right amount for it to be running sweetly.Not the way I slice it - I get about 10 slices out of an 800gm loaf!
Its still not 100% carbs. White bread is about 70% carbs. So 800g loaf is 560g carbs.
Posted 1 year ago # -
I must say I'm very sceptical about that figure, I estimate I take about 300g of carbs a day (ie half my calorie intake) and have done for many years. Perhaps your endocrinologist friend's view is skewed by only measuring sick people ? Or perhaps it's just that people with defective pancreases will succumb to carb overload while normal people won't ?
Posted 1 year ago # -
Perhaps your endocrinologist friend's view is skewed by only measuring sick people ? Or perhaps it's just that people with defective pancreases will succumb to carb overload while normal people won't ?
As a medical professional, he'll have lots of research papers to back up his theory and won't just be making it up. that's why we're always being told to limit our carb intake.
Posted 1 year ago # -
Miketually, you might want to read a few of the numerous articles referenced in these blogs before you roll your eyes:
http://high-fat-nutrition.blogspot.com/
Posted 1 year ago # -
Finbar, I think he was rolling his eyes in the other direction..
Simonbarnes. Thanks for reading my posts and using your intelligence to comprehend the nuance of everything I said previously. Other people find it so difficult to actually read each word an parse its true meaning in the correct context. There is nothing I like better than a discussion with someone who really knows how to listen and combat over a point after reasoned and intelligent consideration.
Posted 1 year ago # -
that's why we're always being told to limit our carb intake
Really? This is the first I've ever heard of such an appalling suggestion. I'm aware we shouldn't eat too much stuff and turn into biffers, but so long as we get enough of each food group I didn't think the proportions mattered.
It's my impression that there are fads where some sort of food or other is held to be essential or toxic, like the current cholesterol thing, and before long it'll be something else.
Posted 1 year ago # -
Don't know about the science, but I for one struggle to put enough energy in my body for mtb-ing - and if on a big day out, I struggle to carry enough food...
TBH I just eat when hungry, whether riding or not, it doesn't really impact my weight and obviously my wife loves me for this ability, NOT.
Posted 1 year ago #
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