By working out your hamstring savage grow plus reviews muscles, you can improve your sprinting ability. These muscles are responsible for starting a sprint and helping you gain speed. Try doing a variation of a leg curl. Start by placing all your weight toward flexed ankles with your toes pointed towards your shins. When the weight is lowered, extend your toes away from your shins, back toward the front. These give your hamstrings more of a workout than standard leg curls.