In hs I had 2 teammates who during the summer ran every workout next to me and even during the season were always right at my level during workouts. They went to nike camp and i didnt and it was during that week that i decided i need to run my easy runs faster (sub 7 pace) and from july and on I ran all my easy runs faster and I ended up being on average 30s faster than them that year. I did not just run sub 7 just for the heck of it. I did it based off of how it felt. I didn't want to go on a easy run and feel like I got absolutely nothing out of it. I ran that easy pace through many 60-70 mile weeks with previous season prs of 16:51 ,4:39, 10:17. The second race of that season I ran 16:06 the later on the next track season I ran 9:58 and 4:33. So I def think running easy runs at a slightly faster pace helps. Consistency is also key here I think that is the only way you'll see the benefits. It is not going to happen over the course of one month.