Usually short hair is more suitable for running because it is very light and is off of your neck so you won't be as hot. But long hair is not that much heavier but can be on your neck. It is your choice, but if you only care about running faster, go with short hair.
The cheetah can run up to 70 miles an hour, but only in short bursts covering distances up to 500metres. They can sustain the speed for only short durations, typically around a minute. If they continue to run at top speed for over that time, they will die of exhaustion.
An adult giraffe's neck may be as long as 2 meters, or 6 feet 7 inches in length. From the lighter side: An adult giraffe's neck- what the heck! Grows as long as it's meant to be- It may be six feet, or even five feet, Or even as short as three.
The Brachiosaurus survived in the Jurassic period by its long neck being able to reach vegetation up high in the trees. However recent discovery has led scientist to believe that the Brachiosaurus has been assembled wrong and that it may actually have a short neck,that has not been validated yet.