> what's that supposed to mean? How do they exercise then when they are not running?

Any other sport? Cycling, swimming, rowing, ball sports, team sports, weightlifting, ...

> I don't think many people who don't exercise running can do 1.5 miles in 9:40.

It's 1.5 miles at 9:40 mile pace; 14.5 minutes total. Much easier than 6:30 pace (what you're imagining).