kartelite wrote:
I'd say around 20% - higher at 18-20, and lower at 30.
I became a "runner" just after turning 19 after I gutted out a 4:48 1600m in tennis shoes one evening at the local track. I ordered track spikes and 2-3 weeks later ran 4:34 with very even pacing. Of course after that point, time came off much slower.
Now at 30, I only go for 20 or so short runs a year, but occasionally still bang out a 6:00 mile on the treadmill just to make sure I can do it...I think if I had to go all-out I could manage low to mid-5:00.
So at both 18 and 30, as a non-runner I've been sub-6 by a comfortable margin. I'm around 190, but lift regularly and definitely haven't "let myself go." I realize that's not the case for everyone...
For a bit more anecdotal evidence from someone who's never been a runner, my brother has never run more than 5 miles in his life, but would always run under 12:00 for his college soccer 3200m, and at 27 recently went 5:20 on an indoor track (he probably weights 180-185 but is pretty "fit"). On his D3 soccer team, I believe that around half of his teammates would crack 12, and even someone who runs a 21-22 minute 5k (think about how that places you in a college race) could likely break 6:00.
I know people here like to pride themselves on being fit and looking at everyone else as super slow, but tons of former HS/college runners, as well as other sport athletes and non-athletes in that age group (cross-fit guys! lol) could manage to dip under 6:00.
By the way, looking at results from local 5k races is a horrible way to judge sub-6:00 ability in the area...there tons of people like myself (probably some of you reading this) who could easily still break 6:00 but have no desire to run a 5k when it would be a struggle to get within 4 minutes of your college PR.
You are a liar.