Size is important in how athletes perform in many sports. For example, professional football players usually are large and strong, basketball players usually are tall and jockeys usually are short. Running is a component of most sports and seems to be inconsistent when it comes to measuring height against performance.
Height Isn't Everything
Height is only one factor in determining running performance. A tall person might have the potential for a longer stride but without an appropriate amount of flexibility cannot reach that potential. Strength is necessary for acceleration, and the ability to absorb oxygen quickly helps a runner endure. In other words, a runner who is shorter than his competitor but has greater range of motion and is stronger and better trained in endurance will run the better race.
Tall for the Sprint
A study published in the "Journal of Sports Science and Medicine" concludes that there is not a specific optimal height for sprinters, but that heights of competitive sprinters fell within an optimum range differing by sex. While both American male and female sprinters tended to be slightly taller than the average American, and very tall or very short people appeared to be less likely to be successful at sprinting, overall body mass tended to be lower than average and had more of an impact on performance than height.
Running for Distance
Distance runners are likely to be average or below average height, but there is no discernible advantage to being short or tall in distance running. It is more important to be lean without a lot of excess muscle to weigh you down. Tall distance runners tend to be very lightweight. Elite marathoner Robert Cheruiyot is 6 foot 2 foot and weighs 143 lbs.
Don't Sweat Your Height
Running, like any sport, requires consistent training in order to improve. While your size might give you an advantage, the intensity and loyalty to your sport is more important to the level or your proficiency. Your height might put you at an advantage or disadvantage competitively, but there is no evidence that running for fitness and enjoyment is affected by height.