Which is more common, having a mile PR under 5:00, or having a marathon PR under 3:00?

Both are true. A sub 5 min mile is both harder to do and done more frequently than a sub 3 hour marathon.

Between age group track and HS, there’s probably easily 10,000 kids that break 5 every year. Almost all of those kids retire from the sport without ever running a marathon.

Milers can't run a marathon, but marathoners can run a mile.

This is kind of an interesting question. I just checked the results for the Twin Cities Marathon in 2019 and there were exactly 198 people (men and women) under 3:00. At Grandma's in 2019 there were 511 (faster course). Some of those are out of state, but it goes both ways with Minnesotans running <3:00 elsewhere so let's just say we had at least 700 people break 3 in 2019. Did we have that many <4:58 1600 performers that year? I'm having a harder time getting data for that, but according to Google there are 1,244 high schools in MN. Many of them probably have one or none, but a lot of the big suburban schools easily have a dozen or more, so it probably comes out to at least 1 per school average if I had to guess. If I were betting I would say sub 5:00 mile is a more commonly achieved feat, mostly because more people attempt it closer to their athletic prime.

My theory is that a 3:00 thon takes more effort for most than a 5:00 mile, but a 5:00 mile takes more talent than a 3:00 thon.

Lots of people especially on this site tend to underestimate how much talent it takes to run sub 5. Im willing to bet 75% of 3:00 +\- aren’t capable of sub 5:00, but almost all sub 5:00 milers are capable of sub 3:00.

You'd probably have to hash this out by gender, too. Breaking 5 feels like a much rarer accomplish for women relative to men than Breaking 3 hours in the Marathon. That's my hunch at least.

S-L-O-W-L-Y for the most part.

Sub-5:00 is much easier. I could do it when I was 13. There was no chance I was even running a sub 90 half at 13.

If you gave me 100 sub-3:00 male marathoners, I bet I could get 80+ down to under 5:00 in the mile in 6 months.

If you have me 100 sub-5:00 milers, I’d say it’s 50/50 if I could get them to sub-3:00 in the same time.

MileSplit MN showed 727 high school kids going sub 4:58 in 2019 (I chose that year because it was the last normal track year). So kind of similar to the marathon estimate, but it doesn't count college racers.

I agree the sub 5 mile is more talent and the sub 3 is more training. I also think there is an age aspect to it. It’s easier for a young person to break a 5 min mile, and it’s easier for an older person to break a 3 hour marathon.

Now in my mid 40s, it’s pretty safe to say I will never break 5 minutes ( I ran several 5:1Xs during training runs a decade ago). I think I have at least one more sub 3 marathon left in me.

Also, aren’t there a couple thousand people that break 3 every year at Boston? I don’t think I’ve ever placed higher than 1500th or so and I ran 2:55 twice there. I think the numbers might be pretty close.

You missed my point.

You could run sub 5:00 at 13 because you were talented, not because you were well trained and disciplined. A large portion of the population will never ever run sub 5:00 no matter how hard they train, while a much larger portion are going to be able to train hard and put in the miles to get that Boston qualifier. Most humans have mechanics that support 6:55 pace much more than 4:55 pace.

I have a teammate who ran 60 mpw his entire junior and senior year, and ended his career with 4:51. Dude now has a 1:18 and 2:46 marathon PR off of less mileage/intensity now.

This!
No idea what the numbers would be but there are a lot of Marathon runners.
Track running is only done in school and college and of course at professional level. Everybody else joins the hobbyjogger world. And if you train hard enough you might go sub 3 hours in a Marathon.

BUT
Would almost all sub 5 milers run a sub 3 Marathon? Absolutely not. Different training, different skill set. Just because some have done it does not mean everybody could do it.

Off of just marathon training (2:4x marathoner) I did a mile race in 5:0x. Given a few weeks to sharpen on the track I'm sure I could've went way under 5, but I prefer mountain running over speed work on the track. So I'll probably never find out but who cares.

I worded that poorly, I meant to say most of if not all sub 5:00 milers are capable of training to break 3:00, but not all nor most of 3:00 marathoners can train to break 5:00.

It should be both for guys who are in their 20's.

I started running as a freshmen in hs, broke 5 in indoor track first year. Then started running xc and road races. I ran 2 marathons in hs junior and senior years. For me breaking 3 was WAY harder than breaking 5. And I seriously trained for those marathons.

You don’t need to run 60mpw to break 5:00. In fact, for many runners, they would run much faster mile races if they trained specifically for that rather than trying to hit some kind of mileage goal. He very well ran 4:51 despite his training, not because of it. I’d posit that many HS “milers” are training more like 5k/10k guys who just happen to race the mile every now and then.

Sustaining 104+ quarter miles at 1:43 takes more talent, training, and discipline than just running 4 of them at 1:15.

It was also much easier for me to break 5 in HS than it was for me to break 3 as an adult hobbyjogger. I think injury resistance is arguably a bigger factor in breaking 3 than it is for breaking 5, mostly because of the typical age demographics that pursue those respective feats. In HS I was indestructible. I didn't know how good I had it! To break 5 all I had to do was a modest amount of off season mileage, then show up to track practice and race. It was fun and I loved every minute of it. In adulthood, by the time I took marathon training seriously enough to have a chance at sub 3, I was battling tendon crap the whole training cycle and barely eked out a 2:58 after hitting the wall hard.

Straight up id say marathon only people runnin mile are muffin high schoolers fr more people run marathon so it bussin fr fr