started running 4 months ago. i run 6x a week. 5 of them are zone 2 45min-1hr. at first i need to walk even i run very very slow. after a month i can already run 30 minutes non-stop. after 2 months, i can run 1hr non stop in zone 2. after 3 months to now, my pace in zone 2 just keeps on increasing like it's just amazing how the body works lol. i remember my first zone 2 was 9:46/km and i had to walk. now my zone 2 running non-stop for 1 hr is around 8:35/km. background: 27M, zero amount of aerobic base, never been an athlete, a sloth since a kid.