The anabolic window (also called the metabolic window) refers to the period straight after your workout when the speed of nutrient absorption and the specific nutrients ingested make the biggest difference in muscle recovery and growth. When your body is anabolic, it is building muscle. When it is catabolic, it is breaking down muscle. When your body is stressed or senses danger, it breaks down muscle for the nutrients it needs to survive. Muscle-building exercises are catabolic in the short-term, since they break down muscle. They are anabolic in the long-term, however, because they stimulate the muscles to grow bigger and stronger in preparation for the next challenge. The sooner you can exit catabolism (breaking down muscle) and enter into anabolism (building), the greater your recovery will be.
Here is more information about the anabolic window:
It's all about timing
An article by Krissy Kendall (PhD and CISSN) from bodybuilding.com discusses the theory and reality of the anabolic window. She says that you need to look a little broader than the first hour after your workout. If your pre-workout meal has enough protein and carbohydrates, then those nutrients should still be running through your bloodstream when you are done with your workout. This means that your body already has the nutrients that it needs and therefore you could go for a much longer time post-workout without losing potential muscle gain. On the other hand, people who have not eaten before their workout or exercise before their first meal of the day should definitely ensure that they get the nutrients that their bodies need as soon as possible.
Your daily nutrition is more important than a single meal
Jeff Barnett from Breaking Muscle reviews a study that measured the effects of consuming protein straight after a workout. While those who got their protein fix straight after their workouts did show greater muscle gain, the difference was minimal and not enough to validate the 'anabolic window' theory. There were issues with this study, however. Firstly, the subjects were untrained athletes. People who are just starting out respond differently to exercise and nutrition. Their bodies aren't used to training in the first place, and their digestive systems are not as adapted at pulling protein into muscle as efficiently as others who have trained for longer. Also, people who are just starting out with weight lifting will generally have a greater muscle response; regardless of whether they are following the best protocols or not. Secondly, this study did not account for carbohydrates. Protein is necessary for muscle growth, but so are carbohydrates! See how carbohydrates are needed for muscle growth. Without studying carbohydrate intake along with protein intake, we are missing too much of the picture to make any valid conclusions. Jeff concludes that the anabolic window probably does exist, but that it is probably a lot longer than the 30 minutes (or hour?) that most people assume. He says that you might even be able to push for up to 6 hours. He said that what was more important was your entire nutritional intake throughout the day. You can have a great post-workout meal or shake, but if the rest of your diet is horrible, the guy that skips his post-workout meal but has his entire eating plan figured out will have a much bigger advantage.
Pre-workout nutrition might be more important than post-workout nutrition
David from How to Beast wrote in interesting article. His viewpoint is that the anabolic window is a myth. He cited studies that were done by bodybuilding nutritionists. These studies found that the nutrition you consume before your workout shows a greater effect than the nutrition you consume straight after. Consuming sufficient protein and carbohydrates before your workout is therefore more effective at giving your body what it needs to grow compared to afterwards. This makes sense, since your muscles will have the nutrition that they need to rebuild while they are breaking down. This would therefore decrease the short-term catabolism of the workout, even though the stimulus is the same. Interestingly, post workout nutrition shortly after exercise did show some benefit. Even though the difference was 'insignificant' compared to getting the right nutrition beforehand, it did make a small difference. That small difference might not be much at first, but tiny differences will certainly add up in the long run. My takeaway: following the anabolic window theory is not as important as it is proclaimed to be, but it does carry some benefit. Just does not benefit us as much as we originally thought.
The anabolic window when you are cutting down on calories
Luke Cafferty from Muscle and Strength outlined the same points as the others did above. Your entire nutritional intake throughout the day is a lot more important than a post-workout meal (or shake). It is only necessary if you are training in a fasted state. Carbohydrates are important because they fill up the energy stores of muscle in the form of glycogen. Sugar is converted into glycogen and stored in the muscle for energy. Bigger glycogen stores equal bigger muscle. Since weight training does not deplete your glycogen stores enough for muscle to significantly benefit from post-workout nutrition, ingesting carbohydrates straight after your workout is not that important - as long as your overall nutritional needs are met and your ate prior to working out. However, post-workout meals can benefit people who are decreasing their overall caloric intake in an effort to burn fat. Since your body has less calories than it needs to function (and will slowly burn fat because of this), you face a greater risk of being in a catabolic state instead of an anabolic state. This is because your body might break down muscle for the nutrients it needs. Your body will most likely do this if it is stressed. A pre and post workout meal that contains carbohydrates is therefore beneficial to people who are reducing their calories because it prevents the body from breaking down muscle to meet its caloric needs when it needs them the most.
Too much reading: Give me a summary!
- The anabolic window is not as important (or effective) as people originally thought.
- It does give you a benefit, but only a little (it can add up in the long run).
- Your pre-workout nutrition is more important than your post-workout intake. Eat well before you work out for better performance.
- Your overall eating plan is the most important. This is where gains come from. Focus on the diet that gives you the most gains.
- Eating carbohydrates straight after a workout will benefit you more if you are reducing your total calories to burn fat.
- Instead of ensuring that you have the protein that your body needs straight after your workout, make sure that it has the protein that it needs all of the time. Choose the right protein for the right time, based on each protein's individual absorption rate.
It is a better idea to focus more on eating right for the entire day and maximizing the hormones that build muscle. STAY STRONG!