Usain Bolt is quite literally the human version of a cheetah. What do they have in common? Their muscle composition.
Muscles are made of muscle fibers. Now, there are two types of muscle fibers: slow-twitch and fast-twitch. People who have a high number of slow-twitch fibers are good at activities that require endurance. A perfect example is a marathon runner. Those who have a high number of fast-twitch muscle fibers excel at activities that require a short, yet explosive burst of energy. Case in point- a sprinter.
You’ve probably realized by now that Usain Bolt has an extremely high number of fast-twitch muscle fibers. What you don’t know his how he got them.
He was born with them.
Everyone is born with a set number of slow-twitch and fast-twitch fibers. Yes, you can strengthen them, but you can’t change them. Much like a Cheetah, Usain Bolt is genetically gifted with an extremely high fast-twitch to slow-twitch muscle fiber ratio. This, combined with his intense dedication to the sport of track is why he is the best sprinter in the world.
PS: This is exactly why Usain Bolt will never compete in any event longer than 200 meters. More specifically, Usain Bolt has a high number of Fast Twitch IIb fibers, which work for less than 30 seconds at a time, making the 100m and 200m races his speciality.