Robust evidence supports dietary protein intake to support muscle protein synthesis after resistance training. However, most studies investigating the effects of dietary protein have been conducted in men. A recent study found that a daily protein intake greater than 1.8 grams per kilogram of body weight optimized muscle protein synthesis in trained women.

Researchers asked 24 young women who regularly engaged in resistance training to engage in two resistance training sessions separated by a four-hour break. After each session, the women consumed 15, 30, or 60 grams of whey protein. These amounts provided the women 1.8, 2.3, and 3.2 grams of protein per kilogram of body weight, respectively. Over 24 hours post-workout, the researchers measured the women’s muscle protein synthesis and blood amino acid levels.

They found that 15 grams of whey protein had little effect on muscle protein synthesis. However, after consuming 30 or 60 grams of whey protein, the women’s muscle protein synthesis increased, especially in the first eight hours post-workout. Interestingly, there was little difference in muscle protein synthesis between the 30- and 60-gram doses.

Current dietary guidelines recommend that healthy adults consume 0.8 grams of protein per kilogram of body weight per day. However, this intake level is likely too low for building and maintaining muscle mass. The findings from this study suggest that increasing the recommended amount, ensuring a daily intake of greater than 1.8 grams per kilogram of body weight, will pay the greatest dividends for promoting muscle protein synthesis in trained women. Learn more about the importance of dietary protein in this episode featuring Dr. Stuart Philips.