You may be fast, but are you really reaching your true speed potential? You’re not unless your training encompasses the five elements of speed. Incorporate all five in your training to reach your true speed potential.
Strength is the foundation of speed. If you’re weak, your legs won’t generate enough force to propel you forward at high speed. Even if you perform speed drills, you won’t get much faster if you lack fundamental strength.
Full article source: http://www.stack.com/2014/12/09/speed-training-program/