I'm a college student running unattached with plenty of freedom to train when and as I wish. I ran 4:28 in High School, but deteriorated badly in the longer distances (10:45 3200). My training consisted mainly of 6 days of running, 7 to 8 miles a day, with no long run, during the off season. During the season I ran short intervals a couple days a week and ran my recovery runs too hard. I only ran my Junior and Senior years, so I considered my training relatively successful. However, I had some problems with injuries (stress fractures and neuromas) After I graduated I decided to try and focus on improving my aerobic capacity.
I've been messing around with the HADD style of training, also advocated by Dave Welch (Priscilla Welch's coach). I have been running 6 or 7 days a week, 60-70 minutes a day plus a 90+ minute long run once a week. I've been continually increasing time ran per week; next week I will be running 9 hours total. I generally run at 75-80% of maximum heart rate; 150-160 BPM for me. On extra easy days I may keep it under 150 BPM. I do some hill sprints and strides a couple times a week.
The problem is, I don't seem to be improving. Two weeks a go, I did a 9 mile run with an average heart rate of 157 BPM in 86 minutes. Two weeks later, I did the same run, in similar conditions, in 88 minutes with an average heart rate of 158! In two weeks, I have gotten worse, if anything. My aerobic pace is still ungodly slow. I've done treadmill testing at 150 and 160 beats per minute and gotten the same pace after three weeks of running. What gives? Should I just go back to hammering it and hoping I don't get injured?