The step-up with knee raise is a lower-body exercise targeting the quads, glutes, and hamstrings. It differs from a traditional step-up in that at the top, you lift the trailing leg up to full hip flexion. This gives the exercise a greater range of motion and more of a focus on powerful hip extension in the working leg. When performed with body weight, these are usually performed for high reps as part of a dynamic warm-up, as cardio acceleration, or as part of the lower-body portion of a workout or circuit.