The Anabolic Window is a window of time when the body is particularly receptive to ingesting nutrients. It is also known as the metabolic window.
It is commonly accepted by bodybuilders to be the 45 minutes or perhaps slightly less after weight lifting.
This is one reason why you will often see people in the gym consuming various protein shakes immediately or shortly after their workouts.
Sometimes it is referred to as The Anabolic Window Theory and is controversial. Some claim there is no anabolic window, some claim there is and specific nutrients need to be ingested to maximize its effect, and some even claim there are multiple anabolic windows. Some people even believe the window “closes” within minutes of finishing your workout.
John Ivy and Robert Portman in their 2004 book “Nutrient Timing: The Future of Sports Nutrition” define it as “The Anabolic Phase in the forty-five minute window following a workout in which your muscle machinery, in the presence of the right combination of nutrients, initiates the repair of damaged muscle protein and replenishes muscle glycogen stores.”
Other researchers (Rasmussen, Tipton, et al, 2000) found no difference when a carb and protein (amino acid) shake was taken up to 3 hours after a workout. As they wrote, there are “similar anabolic responses” regardless of timing. This contradicts the anabolic window theory.
Another study, commonly referred to as Tipton (2001) although it was Tipton Rasmussen etc. as in the above study, found that ingesting nutrients before a workout was more effective, so maybe there is an anabolic window before your workout?
Wikipedia has a good summary.
One thing is certain. Shortly after a workout I and many others are famished and consuming a protein shake or other foods certainly feels good. Also, it is during rest and recovery, not during your workout, that your body grows. In other words, weight lifting workouts are catabolic but the rest and recovery they induce are anabolic. Proponents of the anabolic window theory often claim that consuming the right nutrients after your workout causes your body to shift from a catabolic state to an anabolic state more rapidly.
Despite the controversy and research conflicting this, most bodybuilders believe the anabolic window is 45 minutes or less after you finish your workout. This is what most professional body builders believe and work with and you can’t argue with success.
Here is what I do:
I don’t know if there is an anabolic window or not after a workout, but I am hungry, sometimes ravenous, and there is nothing to lose and maybe something to gain by consuming nutrients shortly after my workout. This might be a shake or a meal since I live close to my gym.
Before a workout, if hungry, I may also consume some easily digested nutrients before a workout. I limit this since as a mesomorph, controlling body fat is an issue.
Window or not, your bodybuilding diet and nutrition are important. Do not use your workouts as an excuse to eat junk food, although the occasional “cheat meal” or snack is fine.