I have a little over 500 miles in now, since starting up after my multi-decade layoff. And I've found that I'm no faster, no more capable than I was after mile 50. My HR shoots up to 170 on even modest hills, although my legs and lungs have plenty left in them at that stage. Today into a light headwind on near-flats, I was doing but 13 mph and my HR was 160! My max HR appears to be about 190 (I'm 37).
The only improvement I can speak of is that I can now ride 40+ miles rather than 15 at a 145-155 bpm pace.
Given that I'm not improving much on a plan of 3-5 rides/week, 12-40 miles each, trying to keep HR 140-160, what should I do? Is it still too early to start doing 180bpm intervals? Any other ideas? It looks and seems like my HR is the limiting factor, so getting that down, so I can train harder without having to be in the 90%+ range seems the proper priority since right now my perceived effort is WAY lower than HR I'd expect.