Time Under Tension, Reframed

Time under tension became a buzzword that confused more than it clarified. The useful version of the idea has nothing to do with grinding through three-second concentrics. It has everything to do with controlling the lowering phase and refusing to use bounce or swing.

The eccentric, the lowering portion, is where the muscle is loaded under stretch and where a disproportionate amount of growth signaling occurs. Two to three seconds of controlled descent, with no collapse, is the target. The lifting phase can be explosive; that is fine and often preferable for power output.

The enemy is momentum. Bouncing the bar off your chest, dropping out of squats, or swinging dumbbells through curls all reduce the work the muscle has to do. If a set with strict form requires lighter weight than your ego prefers, take the lighter weight. The smaller number on the bar is producing the larger result on your body.