In young men, low-load high-volume resistance exercise (30% 1RM to failure) induces greater phosphorylation of 4E-BP1 at 24 hours post-exercise (312% above rest) than high-load low-volume exercise (237% above rest), and this phosphorylation correlates with sustained myofibrillar protein synthesis.

When muscles are worked with many repetitions until exhaustion, the buildup of metabolic byproducts and sustained tension triggers a signaling chain that keeps the protein-building machinery active for hours. This chain turns on a key switch called Erk1/2, which then activates two other proteins, p70S6K and 4E-BP1, that control how efficiently the cell reads genetic instructions to build muscle proteins. The 4E-BP1 switch stays turned on longer than usual, allowing muscle proteins to keep being made for up to 24 hours after the workout.