Why do sprinters have bigger muscles?
Show answer & explanation
Answer: Fast-twitch muscle fibers
They train less often — Wrong. Sprinters train very frequently! The difference is in the type of training (short, explosive bursts) which builds different muscle fibers.
Fast-twitch muscle fibers ✓ — Correct! Sprint training develops fast-twitch muscle fibers—thick, powerful fibers for explosive movements. Marathon runners develop slow-twitch fibers—leaner fibers for endurance. It's training type, not just genetics!
It's purely genetics — Wrong. Genetics play a role in fiber type distribution, but training is the major factor. Anyone can develop bigger muscles through appropriate training.