Carb loading for marathon

pobalita

I am running my first marathon in a few weeks. I've run a 20 miler with no problem - at the time I was eating around 2,000 per day. For my final long training run yesterday, I tried to run 22 miles and completely hit the wall at mile 20. My legs felt like lead, I was shaky and confused, and I felt like I was going to throw up. I still feel wiped out today. I'm sure this happened because I've cut back to 1,500 calories on most days to lose a couple of pounds before the race. Lesson learned. 1,500 is fine for most training days but I should have prepared better for the long run.

I obviously don't want this to happen during the marathon and have been doing some reading on carb loading. I can't figure out how to calculate how many total calories I should be eating a couple days before the race. My regular diet of about 1,800 calories per day should include about 202 grams of carbs (at 45% total calories.) Much of the reading that I've been doing suggests that eating about 4 grams of carbs per pound of body weight for a couple of days before the race is sufficient for carb loading. That comes to about 500 grams (2,000 calories) in carbs.

I looked online could not find a clear answer. Do I eat the 500 grams in addition to the regular 202 grams I'm supposed to eat? That would give me a daily caloric intake of 3,800. I don't think that even on my hugriest days I could eat this.

OR, do I eat just 300 extra grams of carbs per day to bring the total to 500? That would still be 3,000 calories which seems huge.

OR, is there another way to figure out how much to eat and carb load properly?

I'd love some advice or guidelines from anyone who has done this.

acpgee

Just make sure you are carrying food the raises your blood glucose quickly if you hit the wall. I have only experienced that once and it was pretty unpleasant--no coordination, confusion, as you described.

On that occasion, someone from the organization of the event gave me a hotel breakfast serving of jam which brought my brain back to reality.

I've had friends who ran full marathons who swear that having a bag of dried apricots on event day prevented them from reaching glycogen depletion.

zlauerMom

What did you eat during your 22 miler? I would be thinking what you can carry with you during the race to avoid that wall.

When I was marathoning, I never cut calories on long run days or the day before a long run day. I would only cut calories on non run days or shortest run days. You need energy for all those miles or, as you learned, you will have no energy at all.

pobalita

What did you eat during your 22 miler? I would be thinking what you can carry with you during the race to avoid that wall.

When I was marathoning, I never cut calories on long run days or the day before a long run day. I would only cut calories on non run days or shortest run days. You need energy for all those miles or, as you learned, you will have no energy at all.

I ate a bagel and a clif shot gel before I ran.

I had additional gels during the run at 5 miles, 9 miles, 13 miles, and 17 miles. I drank water as well.

ThickMcRunFast

I generally spread out my carb loading the week before the race.

I wil carb de-load the first 72 hours of race week, (its call carbohydrate depletion- it can be used in conjunction with carb loading to max out your glycogen stores...but it does go in and out of favor. i have had success with it) then l eat the bulk of my carbs 2-3 days before, and eat 'normally' the day before a marathon. Dinner would be something like some white fish and quinoa with a salad. I hated eating heavily the day before. I don't know that I'd suddenly shock your system by upping to 3800, that seems extreme. But maybe 2700 each day the week before.

I also take powergels every 45 minutes during the race to keep 'the wall' at bay, but only try that if you know how your stomach will react to them.

Hexahedra

It seems that 20 miles is a magic number because that's around the point your body runs out of glycogen.

http://runnersconnect.net/running-training-articles/cience-of-bonking-and-glycogen-depletion/

zlauerMom

What did you eat during your 22 miler? I would be thinking what you can carry with you during the race to avoid that wall.

When I was marathoning, I never cut calories on long run days or the day before a long run day. I would only cut calories on non run days or shortest run days. You need energy for all those miles or, as you learned, you will have no energy at all.

I ate a bagel and a clif shot gel before I ran.

I had additional gels during the run at 5 miles, 9 miles, 13 miles, and 17 miles. I drank water as well.

I'd consider taking in more during the race. Each of those shots is about 100 calories. Each mile the average person will burn about 100 calories, more if you weigh more. By the time you get to mile 20 you are likely running a high deficit on the calorie front.

Personally, I don't like the shots and gels all that much, but I used them anyway at a rate of about one an hour. I also had people on route that had bananas and other things for me to take in if I wanted it.

Like some one mentioned above, I ate like normal the day before the race. I did my carbo-loading two and three days before, but I didn't calorie count it or really overeat all that much. I had a bagel and coffee before the race.

Good luck and have fun!!