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

  1. Oh man, this post made me realize I know nothing of food and proper nutrition. I eat anything and everything all the time. I do try to eat lots of fruit and veggies, and I try to stock up on protein after workouts but mostly I just eat sweets all the time 😛

    • i love biker/eating stories! one of my best buds is a hard core biker and the other day he called me up, “out on a ride, started bonking, passed a grocery store offering ribs in the parking lot, grabbed a few and ate ’em while i rode.” i was floored…i mean, ribs?!?! i’d never have the coordination!

  2. Ooh I read your article in running times. I wanted to turn to the people on the ellipticals next to me and be like “SHE’S AWESOME!” – anyway, before a race I like to munch on sugary cereal (finally an excuse to eat it!) or crackers because they sit well with me and are good for munching on when I’m nervous! Afterwards I pound the calories with froyo or ice cream or any cold and creamy treat I can get!

  3. Great article again Cait! I discuss high and low GI carbohydrates with my diabetes patients a lot – although none of them are runners so we try to avoid most of the high GI carbohydrates 🙂
    The other thing to remember is that when you combine a high GI food with a low GI food it lowers the GI of the meal over all, so when eaten in combination with low GI, high GI carbohydrates can be incorporated into a meal quite healthfully.
    I try to stick to low GI carbohydrates, mainly brown rice (which is actually medium GI), spelt grains, fresh vegetables and fibrous fruits (apples with skin etc) and dairy products. When I want a high GI post run treat it’s got to be chocolate all the way.
    Eating to fuel my workout has taken some experimentation over the years. Nothing too liquid and no hot meals before I workout. Pre-race usually corn thins with peanut butter or some porridge and then wait about 1.5 hours. Post race or training run – it’s gotta be yoghurt and muesli or banana bread!
    Oh, now I’m hungry….

    • Thanks for the props!!! i’ll bet u could school me in GI foods and i should wrangle u in for a guest post! i think it is important to note that u can lower the GI according to food combo’s, so thanks so much for bringing it up…and like i said, YOU know more than me here! 🙂

      i’m with u, if i eat before i like to stick with oatmeal and nothing too liquidy. and ya, now i need a snack!

  4. Great post!!! I cut out that article you had in RT to save in my “running files” for future reference lol. low/high GI foods is something I do tend to get confused about! Basically all of my friends and family never go anywhere near the high-GI stuff, so for a long time I saw it as “bad”. But, I don’t eat to live, and I don’t live to eat – I eat to run! So you’re right, the high GI stuff has its place for sure. Immediately following a race, I will probably shove whatever’s at the finish line into my mouth – usually a banana, one time I had some mini muffins, pretzels and gatorade, that kinda thing. My fave go-to pre-race breakfast is just a white english muffin with some jam! And yeah, I do love my bagels and my pasta even when I’m not doing a long run or race….and I love that being an athlete gives me more “license” to eat that stuff when I want haha.

    • SCORE!! i made it to the running files!! 🙂 thanks! ya, there are not ‘good’ and ‘bad’ foods, just moderation people, and for runners our moderation maaaay just look like buffet style…but that’s just how we roll! 😉

  5. I try to think about high vs. low GI foods, but sometimes I just want CARBS. I usually drink OJ and try and eat some nut butter of some sort after a long run. Pre-run I’m all about granola bars because they sit well with me.

    • thanks for stopping by!! yea, i’ve have good experience with granola bars too! and i’m with ya…when the Carb monster hits i don’t care what it is, just get that doughy goodness in my belly! 🙂

  6. i totally needed this info! i hear about the GI often but am never really sure what it means…this was a great and informational post for me as always 🙂 hope you are doing well friend!

  7. Pingback: How Runners Can Stuff Their Face At Restaurants But Still Perform At Their Best |

  8. Hey Cait, real good article!! You have very clearly explained the facts about GI and carbs, which seems quite daunting despite being simple. The highlight of the article is the ‘times to eat’ tag; very useful for quick reference for a novice runner. And with all the stuff flowing in on the net about GI, carbs, protein and any nutrition you can imagine, this seems to be clear the air. Good one.

    • Thanks, Logan! I know there IS so much stuff out there on the web, sometimes it can confuse runners further. 😛 Glad my post helped clear things up. 🙂

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