The so-called anabolic window, e.g. getting protein within 30 to 60 minutes post-workout, gets a lot of debate online but its scientific backing rests on shaky ground. A 2013 analysis by Aragon and Schoenfeld concluded that the window may span 4–6 hours around training and total daily protein matters far more than immediate timing (PMC, GSU). Muscle absorbs protein across a broad time frame when daily intake is sufficient (Muscle & Fitness, Verywell Health).
One area where it seems to matter most of taking protein before going to sleep. Studies show that casein taken before bed increases overnight muscle protein synthesis and supports gains in muscle mass and strength during resistance training (Frontiers, JSAMS, ResearchGate). More recent work shows pre-sleep protein boosts both myofibrillar and mitochondrial protein synthesis after endurance exercise.
In practice this means total daily protein intake matters more than precise timing. If you consumed protein before training and again within a few hours after, you’ve already hit the window. So don't worry too much about chasing the perfect time, instead make sure you're getting the recommended amount of protein, which is commonly believed to be ~1.5-2g per kg of body weight per day.