When you lift weights, your body temporarily turns up a molecular switch that controls how fast your cells make proteins, then turns it way down afterward—like hitting a gas pedal and then a brake—to...

In elite male weightlifters, both light and heavy weight training decrease the activity of a protein that slows down muscle protein production, which may allow more protein to be made in muscle cells.

For guys who don’t lift regularly, doing weight exercises doesn’t change a specific body signal (ERK1/2) 30 minutes after working out, no matter how hard or long they train — so this signal probably isn’t what tells their muscles to grow right after a fasted workout.

When you lift weights, your muscles temporarily stop building protein, but right after you finish, they kick into high gear to repair and grow—this happens because key signaling molecules in your muscles get activated during recovery.