The so-called ‘anabolic window’ - the time after your workout when you need to get in a full portion of protein (20-50g), or risk going ‘catabolic’ (aka have all your muscle break down)! It sounds very dramatic, doesn’t it? The exact length of this window of time seems to vary quite drastically - some will say you have up to 3 hours, others will say you have just 1 hour. I’ve even heard one trainer tell a client they had 14 minutes - yes, 14 - to have a protein shake before their body would go catabolic!
Through exercise we do damage our muscles, which then need to be repaired, and protein is what we need to do this. However, the idea that we must consume a full portion of protein immediately after we train, or this muscle will be broken down / we wont recover is pretty much unfounded.
The most important thing when it comes to protein is your overall daily intake. You should be aiming for 1.6-2.2g/kg every day. If you have a protein shake within minutes of finishing your workout, but don’t hit your overall daily intake, then you still wont be able to build muscle, or even repair and retain the muscle you already have.
Even if you are hitting your overall daily intake, the difference between having some protein within 1 hour, or 5 hours after your workout, is going to be minimal. Studies have shown that you get a slight added benefit by consuming a portion of protein within 3 hours of your workout - but nothing significant or noticeable. Unless you are a high level athlete, or training multiple times per day, there is no need to worry about how soon after exercise you are getting your protein in.
Like many nutritional myths, there is a grain fo truth at the bottom of it - you can get slight physiological benefits by consuming protein soon after your workout. However, the ‘anabolic window’ is much larger than we might think, and only becomes relevant if you are already nailing your daily protein intake. So, unless you are a top athlete or bodybuilder, just focus on getting your protein in on a daily basis, and don’t worry about the nutrient timing!