This study shows that increased muscle protein synthesis is correlated with gains in lean muscle mass. Making sure you consume at least 1.6 g/kg/bw or .7 grams per pound of bodyweight and a protein shake immediately post-exercise are good strategies to increase muscle mass.
HOW TO INCREASE MUSCLE PROTEIN ANABOLISM FOR LONG TERM MUSCLE GAINS
Protein anabolism is the process by which the body builds new muscle proteins. It is a complex process that involves many different steps, but the basic idea is that the body takes amino acids (the building blocks of protein) and uses them to create new proteins.
Muscle mass is built when a net protein balance is increased over a prolonged period of time. In response to resistance exercise, consuming essential amino acids after exercise, protein synthesis increases, whereas protein breakdown remains the same. This process of repeated tension overload with increases in muscle protein synthesis ‘drives’ adaptations to exercise training, leading to increases in muscle growth.
MUSCLE PROTEIN ANABOLISM STUDIES
It was once thought that exercise intensities above 60% were necessary for optimal increases in muscle protein synthesis. However, new research has shown no direct correlation between the amount of weight (i.e., ~30-90% of a 1RM) you use and muscle growth when sets are taken to complete failure.(1) This suggests that protein synthesis can occur with both heavy and light weight training when sets are taken to failure.
MUSCLE PROTEIN ANABOLISM STUDY
Increased protein synthesis drives muscle growth responses to resistance exercise. Researchers measured protein synthesis at the beginning of an eight-week resistance exercise protocol in males and females. The resistance training protocol was three days a week and consisted of a superset protocol in the following order: bench press followed by lat-pulldowns, standing barbell press followed by seated cable row, and leg press and leg extensions. Each exercise was performed to failure at 75% of a 1RM for four sets, with 10-12 repetitions with 90 seconds between sets.
All subjects received a protein shake immediately post-exercise following exercise to maximize protein synthesis. The subjects consumed 1.6 g/kg/bw of protein to maximize lean mass gains. 48 hours after the first and last bout of resistance exercise, muscle protein synthesis was measured to examine how protein synthesis changed from the untrained to the trained state after eight weeks.
At the end of the study, muscle protein synthesis increased in both the untrained and trained states in both males and females for 48 hours after exercise. Some studies have found that muscle protein synthesis increases 50% at 4 hours post-exercise, peaks at 109% at 24 hours post-exercise, and returns to baseline 36 hours post-exercise.(2) Others have found that data to MPS returns to peaks at 24 hours post-exercise and can persist for 48 hours.(3)
Contrary to some other research, this study found that muscle protein synthesis was still elevated at 48 hours. The increases in muscle protein synthesis were related to gains in muscle thickness and muscle cross-sectional area in both males and females. Some studies have found reductions in muscle protein synthesis to occur with training over time.(4, 5) Males also showed a greater increase in muscle protein synthesis than females, but both males and females increased muscle growth similarly.(6)