[ck2]

Fast vs Slow twitch has been understood since the 1970s.

You think a body builder could ever run a 10K at sub-6 mile pace or a sub-6 runner benchpress what a body builder could?

[bryanlarsen]

The [citation needed] was for your association between muscle types and training types. For example, it's also a common assertion that intensity training is good for both fast and slow twitch muscles.