TL;DR – Depends on when you had your last protein intake and how much. The window for protein, both pre and post, should be 3-4 hours, unless it’s a larger meal, then 5-6 may be acceptable. So, if you eat at 12PM sharp, you would benefit from completing working out and eating within 3-4 hours of that time.
The general consensus is this: Your main goal is to hit enough protein throughout the day. Generally if you’re doing that and not doing it all in one meal (which, by all means is welcome, but isn’t optimal) you’re probably fine. But for those of you that are interested in the science and/or anxious about doing it correctly, here’s a more adequate understanding based on a meta-analysis here. There are four variables at play here.
- When did you eat your pre-workout meal?
- When did you workout?
- When will you eat your post-workout meal?
- How large will your pre-workout meal be?
Going in order, let’s first examine the first variable: Your pre-workout meal.
The anabolic window, or when you build muscle, somewhat begins at your last meal before you workout, and this is a bit less complicated than it sounds: when did you last replenish your body with nutrients? The simple fact is that when you exercise, you burn calories (which is simply a form of energy), and that energy needs to come from somewhere. You will either burn stored fat, or if you haven’t had protein lately, your muscles will go catabolic and start breaking down to produce energy (this is a bit complicated, and will probably be covered at a later date).
This can be circumvented if you prefer fasted training, and is discussed here by Martin Berkhan.
So you need to be fed before working out (generally). But once again, that supply only runs so long before it runs out and you’re in danger of what’s stated above yet again. This is the anabolic window. This is the most important phase as it dictates the latter steps. After you eat your first meal, depending on how large it is, your window begins, which lasts roughly 3-4 hours.
The second variable: Your workout.
This is simple: eat your meal before you go to workout, offset by about 30 minutes to an hour. So if you want to workout at 12PM, try to finish eating by 11:00-11:30AM. Then, starting from 11:00AM, let’s say your workout takes 90 minutes and it’s now 1:30PM. It’s been 2.5 hours, so you have between 30 minutes and 1.5 hours to have some protein. Simple enough.
Third variable: Your post-workout meal.
This is the simplest variable in theory, but sometimes hardest in practice. The simple part is you only need a marginal amount of protein, 20g-40g generally, but the hard part is getting it in a timely fashion. If you drink protein shakes then it is a simple fix, just bring a protein shake for an after workout meal. The only other solution is either live close or eat a bigger pre-workout meal. Which brings us to the…
Fourth Variable: Meal size.
The study suggests 0.4-0.5g/kg of lean body weight, or 0.18-0.23g/lb as a pre and post workout dose of protein being adequate to push off a catabolic state within a 3-4 hour window, with higher doses of protein increasing that window to 5-6 hours. For me at 191 lbs that works out to roughly 27g-36g of protein before and after working out. My pre-workout is generally either an 8 egg omlette, which is 40g of protein, or 2 scoops of whey, which is 48g. However, that’s generally all I have and thus my window is still relatively small (3-4 hours). Some mornings I add peanut butter toast and push my window probably another hour (4-5 hours). The key to having a larger anabolic window is simply having a larger pre-workout meal for your body to feast off of to a point. If you eat too much, you’ll be sluggish. Too little, and it’ll be meaningless. This requires personal testing, as I can’t tell you how your body will feel. I can handle about 60g carbs, 40g protein, and 20g fat as an upper limit for a pre-workout meal, maybe upward of 50g protein, pushing my window that much further.
To recap: eat 0.18-0.23g protein per pound of lean body mass (to do this, estimate your body fat and calculate: bodyweight X (1-body fat percentage) i.e. 191X(1-0.2) = 191X(0.8) = 152.8, which you then multiply by 0.18-0.23 to get your suggested protein intake.) After eating this, you have 3-4 hours to complete your workout and eat again. Larger pre-workout meals lead to longer time windows.
These variables must be understood together in order to work correctly. Good luck, and enjoy those gains.