I'm 29, running 5 years, averaging 35-40mpw year-round but have been into 50s for some stretches. Mostly very easy 9+ min/mi with a threshold workout and moderate long run, not much vo2 or faster work other than strides or when I did a 5k block a couple years ago. PRs 5k-hm line up pretty well, best performance is 65:00 10mi last spring (53 vdot), but marathon is a bit worse at 3:10 last fall (50 vdot). Lifetime goals of sub-5 mile, sub-60 10mi, and generally getting faster in long distances trail races.
Easy run and workout paces are usually significantly slower than what race times predict, threshold workouts have been stuck at like 6:45/mi for years for example. I have ran 8+ hours a week before, like leading up to the marathon, and 7 hours is generally my target. Which maybe has caused a lot of yo-yoing as it can be hard to consistently hit that with life, injury, etc. But I think I could stick to 5-6 hours, two workouts, and a much shorter long run pretty comfortably.
Which is better for long term growth? Starting to feel like slogging around at 9+ min/mi is no longer relevant to race goals, despite always reading that volume is most important long term. Or maybe I just need to shift gears for a little bit.
Thanks for any advice!