Can Timing your Protein Intake Make a Difference?

In a recent randomized controlled trial, researchers looked into the timing of protein intake in resistance-trained men, who ate high-protein diets, and what affect the timing may have on muscle and strength gains.

Who, What, and How

Scientists looked at 31 young men (average age: 24), who on average had been resistance training for about three years. None had any known health conditions. Each man also reported they slept at least seven hours per night. For eight weeks, participants performed resistance exercised and ate a high-protein diet of 2 grams of protein per kilogram of body weight per day. One group was assigned to eat 25 grams of whey protein immediately before and immediately after exercising, and the other group three hours before and after exercise.

All the men worked out with a certified strength and conditioning specialist during the course of the study, doing a standardized program 4-5 days per week, depending upon their baseline training volume. For nutrition purposes, the participants met weekly with a registered dietitian to provide guidlines on how to reach their protein and energy needs, including being told to eat 4-7 meals per day, each containing 20-40 grams of protein. Researchers had them each maintain daily food records using an app on their phones.

Researchers assessed each participant’s strength based on a 1-repetition maximum (1RM) test for the leg press and chest press exercises. Muscular endurance was assessed via the performance of 1 set of the leg press and chest press exercises using 75% of 1RM until technical failure (i.e., the point at which another repetition cannot be completed with proper form). The participants also completed 1 set of pull-ups to technical failure.

What did they find?

Bottomline: the timing of protein intake around resistance exercise did not affect gains in muscle mass or strength during this study.

It’s a common belief that there is a window of time within about an hour after a workout during which protein should be eaten to result in an enhanced anabolic response, but the results of the summarized study refute this idea: consuming protein in closer proximity to resistance exercise (i.e., within the supposed anabolic window) did not enhance increases in muscle mass and strength.

The study reinforced existing evidence suggesting that total daily protein intake is more critical than protein timing for enhancing muscular adaptations. When diets contain equal protein amounts evenly spread across multiple meals, the timing of protein ingestion concerning exercise does not notably affect muscular adaptations. The paper raised the question of whether there is a threshold where protein timing and distribution significantly impact muscular adaptations. The discussion explored the notion of a saturable MPS process, where ingesting larger protein amounts extends the MPS duration rather than reaching a maximum threshold. Notably, a study highlighted in the paper demonstrated that ingesting 100 grams of protein led to a prolonged MPS rate compared to 25 grams, indicating that excess protein is not wasted but requires more time for digestion and utilization.

To read the full study, visit: https://pubmed.ncbi.nlm.nih.gov/38846541/