The anabolic window and other facts about nutrient timing have been subject to extensive research. Is there such thing as an anabolic window? What to eat after working out to maximize muscle growth? Do you really need simple sugars post workout to replenish glycogen levels? Some experts claim that the food you eat after exercise contributes to muscle growth and repair more than any other meal. Others claim that post-workout carbs aren’t necessary. So what’s the truth? Is the anabolic window just a myth? Let’s get the facts straight once and for all.
What’s the Anabolic Window Anyway?
The metabolic window, commonly referred to as the anabolic window, describes the first 30-45 minutes post workout during which you can maximize muscle growth and reduce catabolism through food or supplements. In other words, the nutrients you take in after exercise can shift your body from a catabolic state to an anabolic one.
As you probably know, muscles actually “tear” when you work out and then gradually recover and grow when you rest. Consuming the proper ratio of nutrients post-exercise is essential to muscle growth and repair. This period is considered the most critical part of nutrient timing.
How Long Does the Anabolic Window Last?
Most health experts agree that the anabolic window lasts for 30 to 45 minutes. Some claim that it begins to close within minutes of the end of your workout. Recent studies suggest that the metabolic window is much longer that we’ve thought and can last up to 24 hours. Amino acid balance and protein synthesis have been found to be the same at 3 hours and 24 hours after exercise.
It has been shown that protein synthesis peaks about 24 hours after working out, which is why it’s even more important to keep your protein intake high on off days.
There’s a lot of controversy surrounding nutrient timing. Most bodybuilders and athletes have a protein shake within 30-45 minutes of their workout, followed by a meal 90-120 minutes later. Some prefer a weight gainer or add dextrose to their protein shake. Ask any personal trainer about what to eat after working out and he will recommend you a similar approach. The best thing you can do is to experiment and see what works best for you.
Getting the Facts Straight
I’m not saying that the anabolic window is a myth. After all, bodybuilders have been using this approach for decades. What I want is to get the facts straight and let you decide whether the anabolic window is real or not.
If you had a pre-workout meal, the food you ate is still being digested and releasing nutrients into your body. Even if you don’t have a protein shake or simple carbs immediately after exercise, you’re still maximizing muscle recovery.
For those who lift weights in a fasted state, post-workout nutrient intake is critical.
According to the anabolic window theory, adequate nutrient intake after exercise helps rebuild damaged muscle tissue and restore glycogen levels. It also enhances physical performance and improves body composition. In a fasted state, muscle protein breakdown peaks at 195 minutes after strength training. Thus, it makes sense to have a protein shake or a gainer post workout.
A combination of protein and carbohydrates will raise your insulin levels to a greater extent than carbs alone.
With that being said, the importance and even the existence of an anabolic window is questionable. Its potential benefits on muscle growth and repair may only be applicable in the absence of a pre-workout meal or previously consumed nutrients.