Quad Exercises

The quadriceps straightens the knee, and one of its four heads also flexes the hip. Squats, hack squats and leg presses load the knee extensors under heavy weight with the hips involved. Lunges and split squats do the same one leg at a time, which exposes and evens out side-to-side differences. Leg extensions isolate the knee joint and let you train hard without a taxing setup or much fatigue elsewhere.

Range of motion matters more here than load: the quads do most of their work in the bottom half of a squat, so a rep that stops above parallel leaves most of the growth behind. Two sessions a week and 10–20 sets suits almost everyone — heavy compound work at 5–8 reps, machine and single-leg work at 8–15. Let the knee travel forward over the foot instead of forcing it back, and add a couple of sets of extensions when squats are limited by your back or hips rather than your legs.