What do the quads do?
The quadriceps is a group of four muscles on the front of the thigh. They straighten the knee, which you use to stand up from a chair, climb stairs and absorb the landing when you step down. One of them, the rectus femoris, also helps lift the thigh.
How do you train your quads?
Squats, lunges and step-ups train the quads alongside the glutes. The deeper the knee bends, the harder the quads work. Single-leg exercises, like split squats, are a good way to make bodyweight training harder without any equipment.