Why do the fastest runners tend to be black?

The fastest runners often come from groups that have practiced running for many generations, just like kids who play a game every day get better at it.

Some people are born with strong legs and fast hearts, which help them run faster. It’s kind of like having the best toys to play with, they make you stronger and quicker right from the start.

In some groups, running is part of life, it's how they move, how they play, and even how they work. Over time, this practice makes them faster and faster, just like how kids who ride bikes every day get better at riding than those who only ride once in a while.

So when we see the fastest runners, many of them are from groups that have had these special tools (strong legs, fast hearts) and lots of practice, it’s not magic, it's teamwork between nature and hard work!