Sprinting uses the same muscles as running, but requires that they are considerably more limber for short bursts of speed while avoiding injury. Running is powered by the legs, hips and glutes, so training the same muscles with a focus on speed will prepare you for sprinting. While training, avoid raising on the toes or pumping too high with the arms. Allow the primary muscles used for running to provide the power to sprint.
The quadriceps are the muscles at the front of the thighs. These muscles raise the leg and propel the runner forward. Muscles throughout your body work in coordinating pairs. One muscle group pulls in one direction and its coordinating muscle group pulls in the opposite direction. The quadriceps work in conjunction with the hamstring as the most important coordinating pair for sprints. The quadriceps pull the legs forward for fast bursts of running. The stronger the quads are, the faster your legs will pull your body forward -- and the faster you'll be able to sprint.
The hamstrings are the agonist muscles at the back of the thighs that work with the quadriceps. They pull the leg back so that the sprinter has the force to push off the ground quickly from the calves. Both the quads and hamstrings work at the same time on alternating legs, so sprinting is quickest when each is toned and elastic for speed. The hamstrings are most elastic when the hips and glutes are strong and stabilized.
The glutes, or muscles of the backside, are some of the largest muscles in your body. Sprinters use them to assist in propulsion and to support the work of the quadriceps and hamstrings. When sprinting, you may find that the glutes work less than the legs. This is a product of overextension. Engage the muscles of the backside in order to avoid injury to the legs.
The hip flexors are a group of muscles that surround the hips and work with the glutes, quads and hamstrings. These muscles are often overlooked, but are crucial to sprinters, because nimble hip flexors allow your legs to move quickly and in concert with the rest of your body's speed of propulsion. Stretching the hip flexors, in particular, is important to maintaining speed throughout your sprint without injury.
The calves comprise two muscles: gastrocnemius and soleus. Some anatomists consider these as one muscle group called the triceps surae. These muscles are vital to sprinting more than regular running, because the muscles of the calves control foot flexion when running. Sprinters should be prepared to spring off the next foot during each stride before impact to minimize time on the ground. Strong, elastic calves support the additional speed of a sprint.
Developing elasticity is the main difference between training to run long distances and training to sprint. Over time, your body naturally accommodates the style in which you train it. If you are training to run generally, your body may not have the elasticity it requires to sprint competitively. Regular stretching of the muscles most important to sprinting will keep your body moving quickly at all stages of each stride.