Personally, I just do it fasted and only worry about hitting my protein goals for the day later on. My understanding is that having a consistent routine and hitting your daily allotment is the vast majority of what’s important. You don’t need to actually do most of what the fitness industry has sold folks on. Your body doesn’t stop looking for the nutrients it needs to repair itself if you consume a protein shake hours later as opposed to right after a workout.
I’m in the same boat, I looked for as many studies I could find on muscle protein synthesis and muscle protein breakdown in regards to IF and at best the results are ambiguous, from what I’ve found.
It is generally shown to be true that muscle protein breakdown (MPB) is slowed when protein is consumed at an adequate amount every 3-5 hours (bad news for IF).
Muscle protein synthesis is triggered by enough intensity in your workouts, which means the lifter requires a certain amount of hard sets for the muscle group. If working out in a fasted state inhibits your physical performance for high intensity workouts, it might be much harder to trigger MPS, again bad news for IF, but this is highly individualistic and I think the best course of action is to listen to your body and do what is right for you.
The good news is that the anabolic window has been largely disproven for MPS. Post workout protein is vastly less important than total protein intake during the day. As long as you get enough protein in your diet, and space it over several meals, it should make little to no difference in building/maintaining muscle.
Just to reiterate I’m not a pro at finding this information, I’m just doing some digging for sources other than some generic health magazine.
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Honestly I think your best bet is to play it by feel and see how you do. I measure my lifting progress month to month by progressive overload either by weight or by reps. I recommend tracking everything on a spreadsheet while accounting for your nutrition on IF, so if you lose progress, you can start to figure out why instead of shooting in the dark and hoping. Alternatively, if you really enjoy the post workout meal, try dialing back your eating window during the day. IF is very flexible.
I have been trying to figure out the same thing! When i did research online, it says that fasted cardio is fine and that you can fast for a few hours after your cardio.
But, that with heavy weight lifting you want to eat right after to repair.
So, it’s tough… because I also was hoping to implement my workouts in the AM. But I’m stuck on how to do that with a good window.