[xarope]

I'm not sure about running specifically (nor this mapping of 5 hours to 30 miles, since depending on your capability as a runner, 5 hours could mean 50+ miles), but cyclists, x-country skiers, triathletes[0] etc rack up more than 5 hours a week, and they are the ones with the massive VO2 maxes, in comparison to the runners who have to suffer from the mechanical impact of running.

[0] as a former wanna-be triathlete, I'd run 2x2 hours a week, swim 2x2 hours a week, cycle 2x5 hours a week. That's probably minimal to be able to complete an ironman, and I'm sure the sub 9 hour folks are putting in twice that, which would be 18 hours[1] to 36 hours of training a week.

[1] that's why I stopped; I figure I can spend about 10-12 hours a week on "fun" exercise including social stuff. Triathlon training on the other hand is very solo intensive.

[riku_iki]

> they are the ones with the massive VO2 maxes

my intuition says that interval running is the best regime for this, and most time efficient (like 15 mins per session: 6x30sec sprints + 6x2m jogging)

[xarope]

I believe there are plenty of studies which show that #1 this is most effective with a strong base, and #2 this regime is only effective for 8-12 weeks, at which point in time you stall in progress, and need to go back to base building again.

[riku_iki]

I skimmed first page of google search results, and couldn't find such statements.