Anabolic window - is it a myth that you should eat more after a workout?

Anabolic window - is it a myth that you should eat more after a workout?

Anabolic window - is it a myth that you should eat more after a workout?
Anabolic window - is it a myth that you should eat more after a workout?

According to the creators of the anabolic window theory   , after training there is an opportunity to absorb more nutrients and therefore improve muscle recovery processes   .

In particular, some authors argue that it is the perfect time to increase your protein and carbohydrate intake. For them, during the anabolic window, the absorption of some  nutrients  is greater.

This article presents the scientific evidence that exists today to say "yes" or "no" that the metabolic window is a myth.

What is an anabolic window?

By definition, an  anabolic window  or  metabolic window  is the period of time that occurs after 45 minutes - 2 hours after training.

According to the creators of the concept, at this time there are enough changes in the body to justify the increase in the amount of food.

The reason seems logical: after a workout, the body makes a transition from  consuming reserves  to  building  tissue.

Unfortunately, scientific evidence has discredited this concept. (3,4,5,6)

Studies have confirmed that it is not important to include more food after a workout. Rather, the emphasis should be on the quality and  proportion of macronutrients  .

History of the anabolic window

The myth of the anabolic window appeared about 10 years ago; where some authors support the theory that eating more in the anabolic window is an effective strategy for muscle development. (1)

The story of the anabolic window originates with Lyle MacDonald and his group of specialists. (6) Lyle believes that in order to maximize muscle growth processes, it is necessary to focus on  post-workout nutrition  .

According to their research, the amount of food after a workout should be about 0.6 - 0.9 g of protein and 0.6-0.9 g of carbohydrates for each kilogram of body weight. That is, consumption of approximately 1000 calories.

Further research shows that Lyle's theory of the anabolic window is not entirely true. Although small changes in metabolism are observed, the difference in the increase in muscle mass is not significant. (4,5,6)

Anabolic Window Myth?

During the anabolic window period, the  metabolism  does not accelerate and there are no significant changes in the basic metabolism.

Studies show that neither  eating 5 times a day  nor eating more after a workout is a good method to increase muscle mass.

The consistency and proportion of macronutrients are most important for muscle development. (6)

Consuming more carbohydrates and protein at the end of exercise has a minimal effect on muscle development. (3)

Closing the anabolic window is important to avoid the process of muscle breakdown. However, this is not the key to grouping or achieving muscle hypertrophy.

For this reason, we can say that the anabolic window is a myth.

Post-workout supplements

To shut down the metabolism, some trainers recommend the use of  gainers or weight gainers  (1)  These are carbohydrate and protein based supplements.

Although effective in the process of filling, they can be completely replaced with  homemade protein shakes to  fruit-based. A really cheaper strategy.

The  branched-chain amino acids BCAAs  are most indicated for reducing cortisol levels and avoiding the catabolic processes that occur during exercise. Although they are not able to close the anabolic window, they are able to prevent loss of muscle mass.


The concept of an anabolic window refers to the time and changes in the body that occur after a workout.

The creators of the theory claim that during the anabolic window a person was able to absorb more nutrients.

It is now known that the effect of the anabolic window on muscle growth is minimal.

Eating more after a workout is not a good way to build muscle mass. Achieving the right balance in the intake of  carbohydrates, proteins and fats  has a greater effect on muscle development.


  1. Interview with Lyle MacDonald: Growth in protein and muscle. Source
  2. Protein intake time after exercise is important for muscular hypertrophy with resistance training. Source
  3. Time for nutrients. Source
  4. Revisit eating time: Is there an anabolic window after a workout? Source
  5. Is there an anabolic window for training after consuming nutrients? Clear contradictions. Source
  6. Determining the anabolic window
    of opportunity. Source