When does running become "easy"?

[Bluetree]

I get in a "zone" alright- it's the "oh crap, I'm still running" zone.

LOL That sounds like my zone, too!

I think a big part is genetics. When I look at him, he's built like a runner. No excess upper body fat/muscle and legs that seem almost disproportionately long. He's in his forties, can still run a 5-minute mile and does the Oly running leg in sub-8.

Of course, he fights to keep from sinking like a stone on the swim, so at least we have that on him!