Much has been made about the importance of protein timing as it relates to exercise; to the point where some may argue that timing is even more important actual daily nutrient intakes (1). It’s practically a mantra among athletes that consuming protein just prior to and/or shortly after strength training is ideal for increasing muscle mass.
The premise is that there is a “window of opportunity” whereby the body is most receptive to anabolic (building) effects… and if you miss it you won’t get the maximum benefit of all of your hard work (2). So how much, if at all, does protein timing matter when it comes to muscle building?
Is time truly of the essence or can you gulp down that protein shake whenever you feel like it?
The Role of Protein in Muscle Building
It is well known protein is required to build and repair tissues – including muscle tissue – and it is often considered the “critical nutrient” in this respect (2). Not all protein is created equal, however. Protein is made up of amino acids and some of these are considered essential amino acids (EAA) – which means the body cannot make them – and some are non-essential amino acids (NEAA) – you still need them, but the body can make them.
It is generally believed that consuming the EAA is a priority after exercise, more so than the NEAA, when it comes to stimulating muscle protein synthesis (3). This is the logic behind supplements containing the branch chain amino acids (BCAA) or other individual amino acids rather than a more general protein powder, such as whey, that will contain both the EAA and NEAA. It has also been proposed that a combination of carbohydrate and protein is required; however, several studies do not support this (4,5,6).
Can protein really help? Well, a recent meta-analysis did find that high protein intakes – either through supplements or in the form of food – IN COMBINATION with strength training exercise increased strength and muscle mass. Although there is always room for misinterpretation, it does appear that protein at least has some role (7).
Please keep in mind that there is an upper threshold (generally thought to be 1.7 g of protein per kg body weight per day) and the effects plateau at that point. Excessive intakes will not be beneficial and this limit includes the total intake from diet and supplements. Importantly, most Canadians already get more than enough protein from their typical diet.
The Role of Protein Timing
Given that the evidence suggest that protein has at least some role in increasing strength and muscle mass on to the next question. Does timing matter? Schoenfeld et al. (2) conducted a meta-analysis to determine if timing has an effect or not. Importantly, they report some studies that say yes and some that say no. They looked at all of the data combined based on two different outcomes 1) increased strength and 2) increased hypertrophy (muscle size).
The found 20 studies for a total of 478 participants that looked at the effects of protein timing on strength. Their overall conclusion was that protein timing did NOT have a significant effect on muscle strength.
They found 23 studies for a total of 525 participants that assessed the effects of protein timing on muscle hypertrophy. Initially, they found a small to moderate effect on muscle hypertrophy but when they reanalyzed the data to control for other factors that could have had an impact they found no effect of timing. What they did find was that the amount of protein consumed was more important than the timing.
No Baloney’s thoughts? Total protein intake seems to have a role in muscle building; however, it can come from either the diet or supplements. Timing doesn’t appear to matter too much for increased strength or muscle mass in the long-term; focus on quantity.
That being said, there does not seem to be any evidence that consuming protein prior to or immediately after your workout is less effective, so you could hedge your bets unless you have a good reason not to. There are also many unanswered questions. This article only focused on muscle strength and hypertrophy in strength training athletes over the long-term. We can’t comment on the importance of protein timing for endurance athletes or for immediate recovery or muscle soreness. There is also some suggestion that the protein type, digestibility, and/or combinations with other nutrients, etc. may play a role.