You use almost exactly the same muscles as in normal running. This mainly involves:
The gluteal muscles (more specifically the gluteus maximus, gluteus medius and gluteus minimus).
The hamstrings, which runs up the back of the leg and consists of the biceps femoris, semitendinosus and semimembranosus.
The large quadriceps muscle on the front of the thigh, which is actually a collection of four muscles (the vastus lateralis, rectus femoris, vastus medialis and vastus intermedialis).
The groin (adductor).
The calves (gastrocnemius and soleus).