Running the Numbers: When to Eat High and Low on the Glycemic Index

Is this bagel high or low on the glycemic index? Am I supposed to be eating low glycemic foods or are it the high ones that are better? Wait, what the heck is the glycemic index anyways?
runner on track
I’m a runner and I love carbs. By now I think we’ve all learned that multi-grain breads are better than the standard white and we should veer towards brown rice over white. But in the flood of ongoing studies and information shoved down our throats it’s sometimes tough to stay up to date on what the latest word is about the stuff that goes in our mouth.

I love exercise because it does make me feel like I have license to chow. The whole ‘if the engine is hot, it’ll burn’ thing, and getting too stressed about what foods are ‘good’ or ‘bad’ isn’t the best thing…and honestly there are conflicting messages; depending on who you talk to and what you read you could end up wondering if there is actually anything you should be eating!

But let’s be honest, to a certain degree we fitness folks have to be aware because part of running our best is fueling our best. So at least informing ourselves enough to achieve our performance goals IS smart. I like the saying, “Eating for performance.”

The glycemic index then rates our foods depending on the rate of which they are broken down by our body and converted to energy; it works off of a scale of 1 to 100.

High GI foods (rated 70 or more) are broken down the fastest; these are our white breads, cereals, potatoes and starchy goodnesses. Here we also have our sports drinks and foods. Think of these ones as the more processed foods.
* They offer up the fastest form of energy once eaten.
* Times to eat: during a race/workout, just prior to a race/workout (like if it’s the last thing you’re having), RIGHT after your run…within 15-30mins
* RECOVERY WINDOW: I’ll say it again because it’s this important, you want a high GI food along with a protein source within 30 minutes after your workout…miss this window and your recovery rate drops at least 60%
fresh carrot
Low GI foods (rated 55 an under) are absorbed more gradually by the body; here are our apples, bananas, old fashioned oats, and beans. These ones are of the unprocessed variety, and usually high fiber.
* Supply gradual, sustained energy
* Keep you fuller for longer
* Times to eat: hours after a workout (post the recovery window you’ll want these guys) and throughout the entire day unless you are actually running or are about to head out

Moderate GI foods are anything in the middle and depending on your workout/running schedule choose from them according to which above category they are headed towards the most.

The bottom line is that the Low GI foods are typically your best bets but it’s important to realize that there ARE times when your body will crave that immediate source of energy. If you’re in a marathon, eating an apple isn’t really going to be doing you the favors you want it to. (and I’d like to see you multi-task that one too! hehe)

I’ve spoken with Krista Austin and in working with Dathan Ritzenhien she shares that before a race he’ll eat just plain, white rice. It gives him the quick shot of energy he’ll need, it’s a low residue food (read as not much fiber which will sit heavy in the stomach) and he knows it won’t cause him any distress. Is it plain? Sure, but he’s not eating it because it will glorify his taste buds…he’s eating for performance.
eating pop tarts
On that note, once your race or workout is done, then you can tantalize your taste buds all you want…I mean you earned it, right? ;)

You can read more tips on how to fuel your running in this article I did: Timing Your Fuel

1) Do you worry about low or high GI foods? Do you try to pick one form of carbs over the other? (ie: whole grain, brown vs. white, etc.)
I do try to stick to whole grains and brown rice/pasta, but I’ll admit to not really keeping track of the GI foods all that well…working on it?? ;)

2) Which, if any, things do you ensure to eat to fuel your running best? Or that you eat because you know it’s best for your body?
Over the years I’ve gotten a lot better at upping my protein, I love eggs, cottage cheese, and shrimp the most. The carby’s I never had a problem with.

3) Thankfully when you are busting your butt you still carry that license to indulge a little more, what’s your top pick? Or, because in heavy mileage it’s sometimes straight up necessary to go for calorie dense foods (hello, Bill Rodgers eating mayo-covered pizza…it worked for him!) how do you pound the cal’s?
Said it a million times, but go to pick for treats are Pop-tarts and Ben & Jerry’s pints…there, said it again.

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