Basically for about 2 years now I have been consistently running daily without a set plan/routine. Coming from a soccer background, I always associated running/cardio with feeling like I pushed myself every time I went running. After researching more on this topic, I've come to realize that is not ideal for someone running high mileage. I have never raced/competed either.
Over the past couple months, I have built up to running 80-90 mpw, mostly around 6:20-6:50 pace depending on the day. Not much speedwork/interval training/strength work. I feel like I am not making much progress doing this, in fact I am probably losing athleticism, strength, etc. as running is so one-dimensional and leaves me feeling sore.
My question is: should I dial back the mileage and introduce consistent speedwork? Should I keep the mileage where it is at and add in speedwork? What about strength training/core work? Lastly, should I follow some sort of plan (Pfitz, Daniels, Lydiard, etc.), even if I do not plan on racing in the near future?