I've recently built up to an average mileage of just over 70mpw over the past 12 weeks. Feel like I've done pretty well with 1 fast midweek workout (normally intervals of some kind, say 6x3min w. 3min jogs at 5k ish effort; or 4x8min w. 2min jogs at 10k ish effort; or sometimes I do a tempo instead), and a long run on the Saturday. The long day has ranged from 15 miles to 20 miles, sometimes just easy 7:30 pace, sometimes with some quality (marathon pace or faster).
Recently I've been having a bit of a crisis of confidence of sorts - thinking that I should be able to handle 3 quality days a week (including the long run; so perhaps intervals, tempo and long)... BUT every time I try to move to 3 quality days and maintain the mileage, I just feel destroyed the following week....
So would I be better off backing down to say 50 to 60 now - a level at which I think I could handle 3 quality days, and therefore a greater % of faster running each week... Or stick at 70-75 and continue with just the 2 quality days?
I'm worried that dropping the mileage to add the quality might be a fine approach for the 10k or half, but that it's less than ideal for the marathon.
Read a lot recently about 80/20 training, and I've realised that mine is more like 95/5 for a week where I do an easy long run, and at best 90/10 in a week where the long run contains some quality. Is that normal?
Previous cycle was 60mpw, again with 2 workouts; but I've been in the 70s for a good three months now.
Any help would be greatly appreciated - I want to be in the best shape across all three distances for (hopefully) October, Nov, Dec races