by Tommy Christian
Reason #1: Mobility
In order to accelerate well, you need to be able to achieve ideal 
biomechanical positions at the end range of your push off and knee drive. Many athletes simply cannot utilize their potential due to mobility restrictions especially in the hip, knee and ankles. One fantastic mobility exercise to release your acceleration restrictions is the ½ Kneeling Quad Psoas Stretch shown below:
Reason #2: Mindset
You have to relax to be fast. Straining to run faster will actually make you run slower. Sprinting isn’t a 1 rep max. It’s not a grit and grind type of activity. It’s a cyclical, rhythmic, fluid, harmonious synchronization of the entire body applying force to the ground during increasingly shorter ground contact times from one step after another. You will find that when you run at 95% effort you will often run faster times as your body is able to cycle between activation and relaxation of the multitudes of motor units that are working in synergy to create movement effectively.
Reason #3: Mechanics
Sprinting well is a very difficult skill that doesn’t come naturally to most people. You may be fast, or you may be slow, but until you’ve worked in developing your sprint mechanics, you haven’t come close to achieving your speed potential. Think about how often a basketball player works on their jump shot, or a golfer on their swing; that is the approach you 
need to take to sprinting. High quality reps, drills focused on different aspects of start, acceleration, and top speed. The Wall Acceleration Series pictured here is a great way to develop the feel for the positions you want to hit in your first 3 steps of acceleration as well as improving your hip flexor strength and glute/core activation in a way that carries over to accelerating.
Reason #4: Weight
If you keep everything else equal, a lighter athlete will be faster. Our goal in strength training isn’t to be big and heavy, but to be powerful and fast. Every sport and position has an ideal range of weight and muscularity. Once you’ve met that range, you need to transition your strength training to rate of force development, elastic strength and starting strength. If you lose 5 pounds of fat, you will absolutely jump higher, accelerate faster, hit higher top speed, fatigue more slowly and change directions more quickly.
Reason #5: Strength
In order to be fast you have to be able to apply large amounts of force to the ground in a short period of time. The first push off in a sprint lasts about .3 seconds, and at top speed, elite athlete’s feet are only in contact with the ground for around .08 seconds. The only force that matters is the force you can develop within these short windows of time. The types of strength you need to focus on were mentioned in the section above on weight. Improving your rate of force development, starting strength and elastic strength will directly translate to your ability to accelerate and sprint fast. Max effort strength work, Olympic lifts and plyometrics are all ways of improving these key speed development strength qualities.