Any athlete who wants to run faster will certainly want to train their hip flexors for speed. One reason is because they are the longest and largest muscle group in the body, comprising of seven different muscles on each side of the body and they drive the acceleration phase of sprinting like no other group. The names of these muscles are: 1) Psoas, 2) Iliacus, 3) Sartorius, 4) Vastus Rectus (a.k.a Rectus Femoris), 5) Adductor Longus, 6) Adductor Brevis, and 7) Pectineus and be seen in Figure 1 below: Figure 1. The Hip Flexor Muscles. The hip flexors are also… read more