Jim Keen is back—and he’s tackling a misconception that’s been baked into isokinetic training since the beginning: that you have to go as hard as possible, every rep, every session, to get results. The key paradigm shift: strength training uses a tool to deliver stimulus to your muscles, while weightlifting uses your muscles to move a tool. When the goal becomes making a number go up on screen, form breaks down—and that’s where problems start.