The typical path towards bulking up is to lift weights regularly and adjust your calorie and macros intake accordingly. But it’s not just what you eat that matters when it comes to building muscle, when you eat is also very important.
Why eating after a workout is important
The main reasons to eat after a workout are: to restore muscle glycogen levels in preparation for the next workout (because working out with low muscle glycogen could reduce muscle growth); to stop protein breakdown which translates directly into muscle loss, unless you increase protein synthesis. Both of these processes happen at a faster rate after a workout so countering protein breakdown can prevent post-workout muscle loss, thus lead to faster muscle gain; last but not least, your post-workout meal will increase protein synthesis, the process needed to counter anabolism (protein breakdown).
When should you eat after a workout?
You might have heard about the “anabolic window”, that period of time after a weight-lifting routine when it’s best to eat in order to optimize muscle growth. Some say that window is very small, as small as 15-30 minutes after the workout. This might be true for some cases, although it doesn’t apply to all of them.
When it comes to replenishing glycogen levels, the restoration rate stays pretty much the same even if you wait several hours after the workout to eat your meal (1). Regarding protein synthesis, eating enough protein throughout the day matters more than eating it after the workout (2).
Also, if you’ve eaten a meal even several hours before the workout, it will keep your insulin levels high enough to stop protein breakdown for about 5 hours (3).
So what really matters when deciding how narrow your post-workout eating window should be, is whether you’ve trained in a fasted state (e.g. waking up early and training on an empty stomach) or you already had a meal that day.
If you already had a meal, you won’t lose anything in terms of muscle gain even if you eat a few hours after the workout. A post-workout meal is more beneficial if you are planning another workout in 8 hours or less (in order to replenish glycogen stores for the next workout) or if you’ve trained in a fasted state.
After you worked out in a fasted state, protein breakdown is even higher (4). Similar to a fasted state is a lengthy workout (3-4 hrs), which would deplete amino acid levels at a high rate, and it would be good to eat a meal as soon as possible once you finished your routine.
In most cases you don’t need to jump on food right after your weight-lifting session has ended and you can eat your post-workout meal even 1-2 hours later. This can be extremely beneficial as it can be difficult (and even awkward if you’d do it while still at the gym) to eat a whole meal as soon as you finished your reps. Also, eating a post-workout snack becomes optional and you can have enough time to shower, go home relaxed, and maybe cook a fresh, home-made meal.