Level 8 Valued Member
Are they sprinters because they were born with more fast twitch fibers? Or they have more fast twitch fibers because they are sprinting? Maybe a combination of two ? Not easy to prove if a long term study is not conducted.
I was terrible at long distance running as a kid.
Not fast enough for 100m, but fast enough for 400m and to play rugby, soccer, and football.
Which made me "bursty" enough to start weightlifting, after which I got more powerful -- i.e. my sprints got faster.
To this day, even at age 53, my sprints are faster and my jumps are higher when I'm competition ready for weightlifting than 6 months out.