Have you been instructed by your trainer to consume protein shake immediately after workout as your muscles are at anabolic stage and protein consumed within 30 minutes to 1 hours after training can help muscles to get maximum nutrition? . If you are one among those who does it, then hold on and let’s explore the science behind it and see if this is a Myth or Facts.
Before we get into the main concept lets first understand the main words used by many fitness trainer and supplement industry in terms of protein i.e Anabolic window.
What exactly is anabolic window? In lame man terms people say that your body goes into a stage of elevating protein synthesis for 30 minute to 1 hour which is called Anabolic window and anything consumed within this period is absorbed by your body at its maximum and help you to get more muscle strength and hypertrophy.
But what if I say research has already revealed this concept as a MYTH as the concept of protein synthesis is much bigger than we think. Well it’s all about muscle protein synthesis and it makes sense that after you finish your workout, you break down muscle fibre and deplete your glycogen stores in your body. Also we know that our body use the glycogen stores as energy to perform exercise and then after completion of glycogen, the fats stored in our body is broken into energy later which protein is used as energy. Though your body can still produce glucose by using the fats stored in our body after workout, so anything consumed 30 minutes to 45 minutes after workout will lead to storing of glycogen content in our body, Hence its recommended not to have anything immediately after workout apart from hydrating your body with water or carbohydrates ( incase of bulking or increasing muscle mass) .As the glycogen storage is replished with the help of glucose, sucrose, fructose ( simple Carbs) or even via complex carbs . And protein synthesis does not begin unless your muscles have enough glycogen stored.

The “Journal of the international society of sports nutrition” and by “University of McMaster” performed research on the timing of protein intake where they tested the level of protein synthesis 1). Immediately after work out, 2). 1 hour after work out, 3) couple of hours after workout. The result was the protein synthesis start to elevate after workout however it reached to 50% high after 4 hours of workout and also to its peak level or more than 100% after 24 hours of workout, which means there was more muscle building and muscle retention capability 24 hours after workout and the level of protein synthesis deplete after 24 hours and doesn’t come to base line until 36 hours after workout.

Even though there are research which shows that consuming protein immediately after workout is beneficial in increasing protein synthesis , those researchers where done on people performing workout on fasted stage of their day without consuming any meal before workout. However if you have already consumed a meal filled with good amount of carbs, protein and fats 3-4 hours before workout then you need not worry about not consuming protein for next 2-3 hours after workout.

That’s the reason we say, there is no point focusing on consuming protein immediately after workout rather focus on having high protein diet through your day, dividing it into equal ratio in every meal. Consuming protein in every meal you eat together with proper ratio of carbs, fats and minerals which can help you to keep the protein synthesis level at its high.

Reference articles.
1. https://pubmed.ncbi.nlm.nih.gov/8563679/
2. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3577439/
3. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5401959/
4. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3381813/
5. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3761704/