Why are some people faster than others ... which limits how long you can run at top speed to relatively short distances. Slow-twitch muscle fibers are smaller and help you run at slower ...

Kirsten Ferguson taught me "runner’s math," surviving side cramps and running form hacks. Plus, she shares a 20-minute speed ...

Trained by six-time Derby winner Bob Baffert, Rodriguez has posted the fastest Equibase figure, recording a 111 for his victory in the Wood Memorial on April 5 in New York.