Hill sprints are an excellent way of creating resistance and building up your legs.If you know how to improve your sprinting speed and conditioning level of fitness then you need to find a flat open field and a couple of markers (cones) to set up. In order to improve your speed and total conditioning you will need to practice putting undue stress on your body by sprinting and implementing variations of sprints. Besides loading the body this is another way to challenge your nervous system to fire quickly which in turn will give you that explosive power you need for speed.