Doing lots of regular runs at half to marathon pace - what would happen

You'd get injured. I run 15:48 in the 5k and do most of my runs at 8 minute pace, no way in heck I could handle doing most runs at 6:10-6:40 and I have run 2 minutes faster than you in the 5k. Just focus on adding volume and your times will improve

It's tempting to run faster in your training, thinking slow miles are junk miles. But it's the MP, HMP miles that are junk miles.

You couldn't do those paces for 20-25 miles.

I could. Just doing 45 minutes 3 times a week would get me over 20 miles. But if it doesn't work I won't bother. I ran 59 minutes for 10 miles on my current training.

You would have zero problems doing all your runs at 6:10-6:40 pace. You seriously don’t think you could 25mpw at that pace? You are nuts. We ran like 25mpw at those paces in HS as 17:00 dudes (2 5ks races + 2 8-10 mile runs in that 6:40 range) The other 20 was slower of course.

Some people have done the run medium fast a lot and done ok. Most tend to do better with splits of 2-3 hard days and the rest easy.

There’s a real place for sub -threshold around HMP.

But yeah, except for a few specific purposes, running MP to MP+ 30 or so in lieu of easy runs = junk miles.

This is the dumbest take I’ve ever seen. Pretty much every professional distance runner does a lot of work at threshold, which is approximately half marathon pace. I’m not saying they should switch all their running to faster paces, but saying HMP miles are junk miles is incredible ignorant.

You didn't read my post correctly. I did not say that I could not do 25 mpw at that pace, I am saying that I could not do MOST RUNS (meaning of my mileage) at that pace. OP is seeking to run 25 mpw, while I run about 60 MPW most of which are at about 8 minute pace, with probably 3-6 mpw in the 5:40-5:50 range, while other weeks some shorter faster intervals at Vo2 max or rep pace. Some weeks I will have quality long runs where I may do 8-10 miles at 6:00 minute pace, but my body is equipped to handle more mileage than the OP. They should focus on just building up their volume of easy runs and then they will be more equipped to do quality miles.

8-10 miles of the long run that is. My long runs get up to about the 20-22 mile range.

And you don’t think when you are running 25mpw you can’t crank them out at faster than 8 min pace? you are really struggling with the idea that hard workouts and mileage slow you down on the other days . Nobody is talking about running 60mpw like this. It is doing 4-5 30-40 mins runs/week. You can run them really fast. As I said you can debate how optimal it is

The post is about running all of your week's volume at a certain pace, for the OP that happens to be 25 MPW. Running your entire week's volume at HMP is a recipe to get injured. Of course I could run 25 of my weekly miles at that pace, I have literally run 26.2 miles straight at 6:11s but I was able to do that partially because of the easy mileage I have run not just the workouts. If I were to only dip to 25 mpw and do only that pace I would certainly lose fitness and eventually not be able to. Running more easy mileage helps your body to adapt to be able to handle more volume. However OP sounds like they are a high schooler (just assuming from their thought process and how low of volume they are doing, if not my apologies) and I am 29 years old with at least 25,000 miles in lifetime mileage, so of course I could handle more volume. The point I am trying to make is that with the times the OP has run do that much mileage in a week for them at that effort would surely lead to injury. They would be better off just increasing their volume of easy runs, which would make them more aerobically developed. Then they would be able to handle a great amount of "quality" miles.

I did pretty much all of my runs at marathon pace. Over time I knocked two hours off my marathon best with corresponding improvements at shorter distances. But I was running a LOT more than 25 miles a week.

^THIS x100.

Your much better off doing CrossFit-style sprint repeats (use the search function, I posted about it). Marathon pace is useless.

What happens when you train at your slow Marathon pace? You get really good at running slow Marathon pace.

Also, Full-Marathons are a waste of time. I like the idea of a 5k Marathon with weighted vest. Those were pretty popular at my box a few years back. Ran quite some respectable times. Probably low 17s if you adjust for the vest.

Been there, done that. It was not effective for me.