Anabolic Window: What It Means and Does It Exist?

We see it all the time in the fitness world; people have barely finished their last exercise and they are digging into their bags looking for a protein shake, or making a move to eat their next meal. It’s during this short time after training that we’ve been led to believe it is ideal for eating and supporting recovery.

…But is it real?

“The ‘anabolic window’ implies that delaying protein intake by one hour or more after exercise will reduce or, worse still, prevent muscle anabolism (growth) during recovery.” (Oliver Witard, a protein metabolism researcher and senior lecturer at King’s College London.) The ideal window is generally believed to be about 30 to 60 minutes post-workout, adds Megan Wroe, a registered dietitian and wellness manager with Providence St. Jude Medical Center in Fullerton, California. “This is when your muscles are most receptive to protein uptake.”

However, Wroe also notes that, “your muscles are always receptive to protein uptake.” So, making sure to eat in that recovery window isn’t a strict and inflexible rule, she says.  Brad Schoenfeld, a certified strength and conditioning specialist and professor at Lehman College in New York also states that protein intake within the anabolic window may not be necessary. He adds, “If there’s any benefit to getting protein within a half hour and 45 minutes of your workout as opposed to a few hours later, and I’m not convinced there is, it would be very narrow,” he says. “As long as you hit daily protein intake, you can build muscle.” It’s important to reach the daily protein requirement for rebuilding muscles. Stacy Cleveland, a registered dietitian at the Ohio State University Wexner Medical Center in Columbus, means that your muscles can really only absorb about 15 to 30 grams of protein at a time. Since the body only can absorb 15-30 g of protein at the time, the excess protein then will be used as part of the body’s overall protein turnover process, either energy or stored as fat.  

As a side note, Wroe adds that consuming protein immediately after a workout may be more important for people who work out first thing in the morning when they’re “still in a fasted state.” It’s also important to think about overall calorie consumption as it is most important for body composition. While consuming protein after workout could be helping to make progress in your fitness journey, if for instance fat loss is the goal, it still needs to be factored into the overall calories per day.  To round off, Wroe adds that “unless you’re trying to meet very specific athletic goals, try not to overthink the post-workout refueling. Research shows that daily protein intake is the most important piece, so make sure you’re eating enough protein and it’s spread fairly evenly throughout the day.” 

To summarize, although the anabolic window is a popular belief that protein should be consumed within 30 to 60 min after workout, research suggests that your average protein intake per day matters more. Focus more on getting enough protein throughout the day, rather than right after workout, except if you are an athlete. Although if you enjoy getting a protein shake after workout it won’t hurt, keep doing what works for you!