The “anabolic window” concept suggests that protein should be consumed immediately post-workout to enhance strength and hypertrophy, but this concept has been questioned in recent years. This study evaluated the effect of protein timing on lean body mass and strength improvements in untrained, post-menopausal women.
34 women were assigned to either a protein-carb group (30g protein post-workout, then 30g carbs ~6 hrs later in the day) or a carb-protein group (30g carbs post-workout, then 30g protein ~6hrs later). Total daily protein was similar for both groups (~0.9-1 g/kg/day, plus the supplement), with minimal dietary protein (aside from the assigned supplementation) in the hours before and after training sessions. The subjects participated in a full-body training program 3x/week throughout the 8-week study.
Both groups had similar increases in strength (1RM bench press and leg extension) and lean mass. This study suggests that consuming protein immediately after a workout may not promote additional benefits for lean mass or strength gains. Intuitively, this makes sense; muscle protein synthesis is elevated for 24-72 hours after resistance training, so the exact timing of protein feedings in proximity to the lifting bout probably isn’t absolutely critical.
Having said that, there is a limit to which we can stimulate protein synthesis in a single meal, and protein synthesis is transiently elevated in response to feeding before returning to baseline. It’s advisable to have at least three separate protein boluses of ≥0.24 g/kg of protein throughout the day. If you’re interested in minimizing the likelihood of leaving any gains on the table, it’d also be a decent idea to place your workout somewhere between two of those protein boluses, and to separate the pre-workout and post-workout protein servings by no more than 4-6 hours.
The bottom line: Ultimately, there’s no real downside to getting some protein in around your workouts. However, multiple studies have suggested that total daily protein intake and distribution are more important than peri-workout protein timing when it comes to strength and lean mass gains.
