"You need to replenish only 20- 30% of the calories you burn per hour"

Yo Sake · Apr 13, 2011

The above quote was taken from Q&A section in the Bicycling magazine where Chris Carmichael was answering to a reader's question, "My friend wants to enter us into an off-road stage race this fall. I'm fit but not that fit. Help!". His above comments followed "For efforts less than one hour, water is enogh, Gels and sports drinks are helpful during longer workouts". 
 
This suggested % seems to be way lower than what I generally try to tintake, though I don't recall off hand how much I burn on the bike. I think I heard in the past, a good rule of thumb is 2cal/lb/hr, something like that? Also, do you think this also applies to running as well? I tend to take a fewer calories than suggested during a run and I tried to take more in, resulted in some issues. It seems I take less than 20% in general, (unless forcing myself to eat more) with little issues. Maybe, I may be trying to eat too much on bike, which contirubted in the past my puking issues. 
 
Discuss.

mrscoby78 · Apr 13, 2011

I don't know about on the bike, but during a run, just water for < 1 hr is what I've always heard. I still have problems trying to figure out the nutrition thing too...I usually end up not taking enough. But, I haven't had puking issues. My problems come...uh....at the...uh...other end.
 
As I've posted previously, I was a miler/5k girl all through high school and college. I've done all of 3 tri's, 2 sprints and a shortened Oly. The idea of nutrition is still relatively new to me. 
 
I have learned that for me, during a half marathon, a pouch of Sport Beans around the 7-8 mile mark along with water or gatorade at the provided stops and I'm good to go.

niemsco · Apr 13, 2011

Tough to say, is he talking about a bike race or triathlon. You don't want to go onto the run from the bike undernourished. I figure I may burn 600 calories and hour in a half iron (maybe more I never checked ). I would take in near 300 and hour regardless, so that's 50% maybe in reality 40%. On the run I'd take only 200, but I would probably burn more like 800 and hour, which seems more in line with the above thinking. Under calories on the bike leads to bonking. Based on a 140lb male.

Yo Sake · Apr 13, 2011

He is talking about just cycling. Racing or training shouldn't matter, should it for this discussion.

pcsronbo · Apr 13, 2011

Racing v Training matters due to intensity and the carb vs fat burn % at those intensities.
 
I have been moving up to 400-500/hr on the bike and 200-300/hr on the run. But I'm probably burning 800/hr on the bike and 1000/hr on the run. (For Iron planning)
 
But on a z2 training ride, I might burn 700 and consume 300.
 
based on 220lb male

niemsco · Apr 13, 2011

<div class="quote-container">Quote:
<div class="quote-block">Originally Posted by Yo Sake <a href="/forum/thread/73438/you-need-to-replenish-only-20-30-of-the-calories-you-burn-per-hour#post_1994101"><img alt="View Post" class="inlineimg" src="/img/forum/go_quote.gif" style="border:0px solid;"></a> He is talking about just cycling. Racing or training shouldn't matter, should it for this discussion. 
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If he is talking about cycling shorter distances (say less than 80 or so), then sure you can get away with 20-30% I would think. Sometimes I under calorie myself on long bike rides because I don't want to carry stuff, though not when I'm 12 weeks out from an A race. I could probably ride 3 hours just on water. But racing triathlon and bike riding or even racing are completely different in terms of nutrition intake if you ask me. Really, I would ignore the article altogether

zojmn151 · Apr 13, 2011

Just chiming in, but I know that for me, I can get away with just water for short rides (30-40 min) but anything longer than that, I have watered down gatorade or similar in my bottles. Longer than 1 hour, watered down gatorade and some type of food, whether it is a GU or part of a bar...
 
For runs, anything over 5 miles, I'll take my fuel belt so I have fluids and for a 10K, I'll have a GU somewhere around mile 4 if I feel I need it. 10K takes me ~1 hour to do.
 
I think you have to play around with the nutrition to see what works for you.

jkaiser20 · Apr 14, 2011

I've seen these discussions before. I think the word "need" has to be defined. Not taking a drink during a 10 miler in the heat will probably not impact my time. Taking only water during a 40k TT will probably not impact my time. So for racing, maybe I don't 'need' much. However, if I go run a tempo 10 miles in the heat for training and not take in some water, it sure as heck is going to impact my recovery, and thus the next couple workouts, thus my overall plan will be impacted. Ditto for biking, maybe even worse. Go for a 3 hour ride with nothing but water in the evening and try a four miler the next morning.
 
Kardong tried to run marathons without taking anything at all due to stomach issues. Didn't work so well.

jroden · Apr 14, 2011

The point of taking calories in during exercise for non ultra distance activities (say 3-5 hours) is to spare glycogen stores so you can work at a higher output than would be afforded by fat burning alone. Your goal is not to replace all the calories on the fly. I rode 4.5 hours the other day and the powertap said that was 3600 calories. I had 2 gu's and 2 bottles of water (there was noplace to get water, i was bingo last 2 hours) and did not bonk, but was close. If the ride had been another hour, perhaps quite a bit more foood was required.For your marathon runs, i'd think a couple gu's and whatever kind of sweet liquid they hand out should be fine.

Dougie Fresh · Apr 15, 2011

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<div class="quote-block">Originally Posted by mrscoby78 <a href="/forum/thread/73438/you-need-to-replenish-only-20-30-of-the-calories-you-burn-per-hour#post_1994085"><img alt="View Post" class="inlineimg" src="/img/forum/go_quote.gif" style="border-bottom:0px solid;border-left:0px solid;border-top:0px solid;border-right:0px solid;"></a>
I have learned that for me, during a half marathon, a pouch of Sport Beans around the 7-8 mile mark along with water or gatorade at the provided stops and I'm good to go. 
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Same here. I just had water at all the stops (I cannot do straight Gatorade) and had a gel right at 7mi during both my halfs last year and it was perfect. I was spent at the end but not the kind of "bonk" spent -- the right kind of "I've given it my all" spent. 
 
I also found that a burger and a beer or two after the race helped too. Recovery is very important.

Yo Sake · Apr 15, 2011

Thanks for your input. 
 
JR's point made me think and re-read the article. Carmichele's answer might be related to his plan of training for long endurance ride, in which I am sure you have to train your body to store high glycogen and improve fat utilization. I guess by limiting calorie intake your body will try to use fat instead of relying on glocogen in the course of training period.
 
jkaiser's comment is so true. When I started a marathon training on an annual basis, I took an idea of limiting calorie intake during a long run to improve fat utilization. So it was common to run 2.5hrs+ with just water. But after a while, I realized my recovery was aweful. It was counterproductive. Dougie got it right - recovery is very important.

mrscoby78 · Apr 15, 2011

This exactly.
 
I swear, after a half marathon, I'd rip my own arm off for a burger. 

<div class="quote-container">Quote:
<div class="quote-block">Originally Posted by Dougie Fresh <a href="/forum/thread/73438/you-need-to-replenish-only-20-30-of-the-calories-you-burn-per-hour#post_1994583"><img alt="View Post" class="inlineimg" src="/img/forum/go_quote.gif" style="border:0px solid;"></a> 
Same here. I just had water at all the stops (I cannot do straight Gatorade) and had a gel right at 7mi during both my halfs last year and it was perfect. I was spent at the end but not the kind of "bonk" spent -- the right kind of "I've given it my all" spent. 
 
I also found that a burger and a beer or two after the race helped too. Recovery is very important.

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jroden · Apr 16, 2011

<div class="quote-container">Quote:
<div class="quote-block">Originally Posted by Yo Sake <a href="/forum/thread/73438/you-need-to-replenish-only-20-30-of-the-calories-you-burn-per-hour#post_1994642"><img alt="View Post" class="inlineimg" src="/img/forum/go_quote.gif" style="border:0px solid;"></a> Thanks for your input. 
 
JR's point made me think and re-read the article. Carmichele's answer might be related to his plan of training for long endurance ride, in which I am sure you have to train your body to store high glycogen and improve fat utilization. I guess by limiting calorie intake your body will try to use fat instead of relying on glocogen in the course of training period.
 
jkaiser's comment is so true. When I started a marathon training on an annual basis, I took an idea of limiting calorie intake during a long run to improve fat utilization. So it was common to run 2.5hrs+ with just water. But after a while, I realized my recovery was aweful. It was counterproductive. Dougie got it right - recovery is very important.
 
 
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I do not think trying to restrict calorie intake during training is effective, as you noted it makes your recovery longer and you tend to keep training while depleated so dig yourself in over a period of days or weeks. 
 
That said, I think sometimes triathletes get a little overboard with all these "nutrition plans" to the point where they are carrying around way more food and water than needed. 
 
For a typical person, you need to start planning on sparing glycogen in exercise over 3 hours. To do so, you need to start consuming calories earlier, maybe 90 mins forward. For say 4 hours, you may not need much.
 
You have been struggling with the marathon for a while, perhaps you are a person who just needs a bit more food to complete a race of nearly 4 hours, hopefully your stomach will be ok with that.
 
I think between the people who make a living coaching recreational athletes and those who sell complicated maltodextrin suspensions to drink or nibble, there is a whole industry supported by making simple stuff complicated.

"You need to replenish only 20- 30% of the calories you burn per hour"

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