I know most here are talented. I am less so, but can still break 5 with about 6 weeks of 20 mpw and a few 400 workouts. Saw the same topic but with the 6 min mile and thought that was way too easy so asking for 4:59.99!
Or at 40 miles/week it's almost a given, even if zero emphasis is put on mile training. (no speed/strength workout..).
Assuming these conditions :
- No particular physical issue that would prevent someone to run "fast", no injury etc.
- Easy run being at least 9:45-10 min/mile.