Want to recover better? Pay attention to your glycogen window! Or not?

I've never met an athlete that did not want to perform better.  Can a performance advantage be gained by something as simple as eating within a fixed period of time after your workout?  Maybe...or maybe not.

I can't recall the first time I heard the term "glycogen window."  I've also heard it called the "window of opportunity", the "carbohydrate window", the "metabolic window", and I'm sure there are others.  I feel like this was a "truth" that was taught to me many, many years ago and since then has been reinforced.  And certainly something I practice.

If you're not familiar with any of these terms, it's the notion that your muscles are most receptive for glycogen (the stored form of glucose (sugar) that is made up of many connected glucose molecules) replenishment within the first 30 minutes upon completing your endurance exercise.  Many experts in the field suggest a 3 or 4 to 1 ratio of carbs to protein to maximize the uptake.  Since carbs and protein both have 4 calories per gram, one can simply look at the number of grams of carbs and compare it to the number of grams of protein.  For example, if the food item at 40 grams of carbs and 10 grams of protein, that would fit the bill of a 4:1 ratio.

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That's right, 3 or 4 times as many carbohydrates as protein.  So you may want to reconsider if a protein shake or bar is your go-to recovery food after that hard cycling workout.

Please understand that these recommendations are for after intense and/or "long" bouts of exercise.  A 60 minute Zone 1 recovery spins doesn't need major refueling.  A spin to the coffee shop on the beach cruiser while on vacation won't need any refueling.  But a ride or event where you're putting down the power or riding for over 60 minutes with a fair bit of aggression, your muscles will get tapped of their glycogen.  And that's a notion that is not argued by many.  However, there are some instances where exercise less than 60 minutes may require some attention to refueling, such as a 'cross race, crit, or TT.

Back to the "window"...

If you dive into this and do some research, you'll find more than one source that says this window does not exist, or if it does, it is much, much longer.  I've seen as long as 24 hours after completion of exercising proposed.

Personally, I subscribe to, and try to practice the 30 minute window.  I also recommend this to the athletes I coach.  I don't have any muscle biopsies to back up my thoughts, but I do have decades of practical experience with three main points why I think it's a good idea to eat within 30 minutes.

1.  Almost everyone I work with is busy.  It's part of our culture.  We cram more and more into our days.  If you make it a habit of eating/drinking within that 30 minute window, it will get done.  I've had more than one client tell me how they "forgot" to eat when they got done or "ran out of time" or "didn't have anything handy" and ended up going for many hours or worse, going to bed without refueling.  Almost without fail, they didn't feel great during their workout the next day.  And maybe even days after that.  So if you make it a routine and maybe even have your recovery meal or drink prepared ahead of time, you'll be sure to get it in every time.

2.  If we eat something sensible and planned during that 30 minutes, we're less likely to raid the cabinets and refrigerator and make bad choices later on.  Those bad choices can often lead to filling our bellies with non-nutritious food, only to be hungry again after a very short period of time.  Get in a good recovery mean or drink, and you'll set yourself up for better choices later on.

3.  You will recover better and feel stronger on your next ride.  Again, this is purely anecdotal for me, but I've worked with many athletes since becoming a coach in 2005, and have heard both successes and failures.  Often those failures can be traced back to poor refueling the day before.  I know I've certainly put myself behind the eight ball after not being prepared or cutting my time to close to properly refuel.  Better to end your ride 15 minutes early and get some food than to push it and put yourself in a hole.  Consistency is going to pay off more than intermittent solid workouts.

Dr. Allan Lim is one of my favorite exercise scientists to read and listen to.  Not only is he extremely knowledgeable, experienced, and interesting, he also delivers down to Earth, practical advice.  You probably know his company, Skratch Labs, and may have come across his books.  Here's a great quote from his Feedzone Cookbook.

WORDS OF ENCOURAGEMENT After racing or training more than 4 hours, it’s critical that you eat at least 4 grams of carbohydrate per kilogram of body weight within 30 minutes of finishing. For exercise lasting less than 2 hours, the goal is 2 grams of carbohydrate per kilogram of body weight. This amounts to about 500 to 1,000 kcals for a 150-pound athlete, depending on the duration of training. Generally speaking, this means that you will eat as much as possible right after getting off the bike if it has been a hard day of training. After an easy day of training, you will eat enough to take the edge off. We need to eat immediately after exercise because our muscles are extremely sensitive to insulin during this time. Insulin brings carbohydrate into the muscle, where it can be stored as glycogen. Consequently, eating right after exercise helps to better restore muscle glycogen.

“The Feed Zone Cookbook: Fast and Flavorful Food for Athletes,” by Biju Thomas & Allen Lim

Much like I wrote about a cool-down, I have not seen any literature or research that says it's detrimental to take in a recovery meal or drink within this 30 minutes.  The biggest downside I see is perhaps taking in too many calories at this time or slamming a big recovery shake after an easy or very short ride.  However, if you keep in mind the notion of the recovery meal or drink is for long and/or intense rides, you'll probably be in a good place.

Below are some other great listens and reads you can use as resources to help make your own informed decisions about your refueling practices.
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Dr. Allen Lim on The Gravel Ride

https://thegravelride.bike/dr-allen-lim-founder-of-skratch-labs-talks-gravel-nutrition
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What Post-Workout Nutrition Looks Like by LENTINE ALEXIS

https://blog.strava.com/post-workout-nutrition-16547/
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The Truth About The Post-Exercise Fueling Window from Women's Running

https://www.womensrunning.com/health/food/the-truth-about-the-post-exercise-fueling-window/
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And if you really want to "nerd out", check out this article:
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International society of sports nutrition position stand: nutrient timing

https://jissn.biomedcentral.com/articles/10.1186/s12970-017-0189-4
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I also found one article where they referenced a study that noted eating anything, even something "unhealthy" is better than nothing at all.

https://www.bicycling.com/health-nutrition/a20014558/what-to-eat-after-a-ride/
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Remember that there are plenty of real food options out there that will work well for recovery foods and drinks.  Chocolate milk is great in a pinch, too.  However, those recovery powders and bars are certainly convenient and going to be better than nothing.

Until next time, fuel ahead of time, fuel during, and re-fuel after.  And the rest of the time try to practice healthy nutrition.

If you have a question or comment, please post below.

Cheers,

Coach Brian