Does the Window of Opportunity Exist for Post-Exercise Nutrition?

Rebuilding damaged muscle tissue and restoring energy reserves after exercise

By Michael Ormsbee, PhDFlorida State University
Edited by Kate Findley and proofread by Angela Shoemaker, Wondrium Daily

Those in the nutrition world have long believed that it’s important to eat immediately after an intense workout, taking advantage of the window of opportunity. Professor Ormsbee explores the latest research on post-exercise nutrition.

Post workout healthy meal
Post-exercise nutrition means that athletes should consume the proper ratio of nutrients immediately following exercise to rebuild damaged muscle tissue and restore energy reserves. Photo By Monkey Business Images / Shutterstock

Post-Exercise Nutrition

Whether you’re just getting started on an exercise regimen or you’re a competitive athlete, it’s important to consider the food you eat before and during exercise. However, post-exercise nutrition is widely considered the most critical part of nutrient timing

Theoretically, consuming the proper ratio of nutrients immediately following exercise can initiate the rebuilding of damaged muscle tissue and restoration of energy reserves. This may enhance both body composition and exercise performance.

This entire concept of consuming nutrients immediately post-exercise for maximal gains is often referred to as the window of opportunity, or your anabolic window. Generally, this anabolic window is considered to be within 30–60 minutes after your workout. 

Is this anabolic window as small as we think, though? Do we need to rush to the protein powder or smoothie station as soon as we drop a weight or get off the treadmill in order to maximize muscle protein synthesis and recover fully? Let’s start by looking at general recommendations for replenishing your fuel stores post-exercise. 

Replenishing Glycogen

The first issue is your rate of muscle glycogen re-synthesis or how quickly you can restock your stored glucose in your muscles and liver after you depleted them during exercise. Eating carbohydrates within 30 minutes of finishing your exercise seems to result in a greater rate of muscle glycogen re-synthesis than if you delay eating carbohydrates by just two hours. 

The benefit to eating quickly after a workout is thought to be due to your muscles being more insulin sensitive at this time. This means that your muscles make more efficient use of insulin immediately after exercise.

Some studies have suggested up to 1.5 grams (g) of carbohydrates per kilogram (kg) of body weight is needed after a workout, or 225 g of carbohydrates for a 150-pound (68-kg) person. However, far less than this is actually needed or beneficial for glycogen re-synthesis.

Immediately post-exercise, you should aim for a higher glycemic index carbohydrate source like a bagel, a muffin, pasta, or cereal. Some research shows that a beverage with glucose and fructose might take advantage of certain sugar transporters and allow for the best rate of glycogen re-synthesis. 

The research also shows that adding protein to your carbohydrates after your workout may help to further the increase in glycogen storage and also increase muscle protein synthesis. The ratio of three to four grams of carbohydrate per one gram of protein in the post-workout meal is the general recommendation for these benefits to occur.

The Anabolic Window

Let’s go back to this question of the anabolic window. This concept suggests that in order to maximize muscle protein synthesis and prevent protein breakdown, you should consume nutrients as soon as possible after working out. 

That seems like common sense. The quicker you get your fuel back into your cells, the quicker you can build muscle.

It’s not that easy, though. While there is plenty of research regarding this window of opportunity, a new school of thought is emerging. 

According to Professor Ormsbee, the anabolic window exists, but the answer as to whether or not it is a window of opportunity is that it depends. Scientific evidence supports the idea of an anabolic window, but it appears to be not as important as we originally thought. 

For athletes who are competing extremely hard, or performing two or more workouts per day, then the window of opportunity is very important to maximize muscle glycogen re-synthesis and protein synthesis so they can begin the recovery process as soon as possible. They need to train or compete within just a few hours.

However, for most individuals, while this window of opportunity still exists, it is not necessary to change your habits to take advantage of it, although doing so may optimize your results. For example, if you work out on Monday morning and then eat normally all day long, by the time you get to your workout on Tuesday morning, you’ll have no issues with glycogen storage or protein synthesis. 

Can you restore or repair faster by consuming the proper nutrients immediately post-workout?

“Maybe, but if you don’t, it’s not a big deal,” Professor Ormsbee said. “Unless you exercise again within a few hours, I would suggest you shift your focus more to the total amount of protein and carbohydrate you eat over the course of the day as opposed to hitting the window of opportunity. I personally aim for a post-workout nutrition shake, but this is part of my normal habit and in line with my current exercise goals.”

For improvements in body composition, understanding your total daily nutrition needs will play a key role, while post-exercise nutrition may play a supporting role.

This article was edited by Kate Findley, Writer for Wondrium Daily, and proofread by Angela Shoemaker, Proofreader and Copy Editor for Wondrium Daily.
Dr. Ormsbee is an Associate Professor in the Department of Nutrition, Food, and Exercise Sciences and Interim Director of the Institute of Sports Sciences and Medicine in the College of Human Sciences at Florida State University.

Michael Ormsbee is an Associate Professor in the Department of Nutrition, Food, and Exercise Sciences and Interim Director of the Institute of Sports Sciences and Medicine in the College of Human Sciences at Florida State University. He received his MS in Exercise Physiology from South Dakota State University and his PhD in Bioenergetics from East Carolina University.