Increasing ground contact forces by way of sprint strength training will help improve the start and acceleration phases of sprinting. Sprint strength training through the use of sleds, incline hill sprints, harnesses, tubing, parachutes, and staircases allow athletes to sprint through resistance.
Sprint strength training should not compromise sprinting form. It will require explosive efforts against moderate and high resistance.
Exercises should not increase or decrease the athletes speed by more than 10%. The grade of incline hill sprints should be between 1.5-3 %. Rest periods should stay between 2-5 minutes between each sprint. Distance should be no more than 0-20 yards and repetitions should stay in the 2-4 range.
Dintiman, Ward: (2011) Encyclopedia of Sports Speed