A lot of
things may run through your head when you're performing a squat: the number of remaining reps, the sweat trickling down your back, the girl on the treadmill. But you probably don't think about your feet. "That's a mistake," says Nick Murtha, a coach for Thrive Training Systems and CEO of Elevate Fitness in Miami Lakes, Florida. "You can instantly increase your gains by 'screwing' your feet into the floor."