The whole premise of this discussionis wrong. No, sprinters are no Mr. Olympians and endurance athletes are not famined ethiopians (though some are ethiopian). Go look at Lance on the cover of Men Quarterly. Or Chris Leigh. Then go look at Michael Johnson. Johnson's legs/bug are bigger, but that's really it - and he's about the fastest guy ever.
And endurance athletes need to spend time in the gym just like the sprinters. They need to build their slow twitch, fat burning muscles where sprinters need to build their fast twitch, gylcogen burning muscles. They often do this with slow slow, low-count reps.