Well I've been at it for a while now and the ragweed has cut me low. I took off a day and today used my trainer. While rewarding it's not the real thing. Northern Virginia is replete with hills; what I'd give for a few miles of flat middle west riding! Anyway the limitations of age are finally hitting home. On most of the killer hills (for me) I'm in the lowest gear and watching my HR reach and in a few cases exceed my predicted MHR. At 135 my breathing becomes heavy and over 140 I'm gasping and past 145 my peripheral vision starts to go. No, I'm not even trying to macho it out, I'm just trying to keep the bike moving. My resting heart rate is (or was before the weeds cut in) 53 BPM so I don't think I'm that out of shape.
For you guys in the over 50 range what sort of improvements have you noticed as you continued biking? I have a feeling I'm expecting them to come too quickly. Have you found the MHR is an immutable/unchangeable limit? It never increases despite fitness? I gather as you ride your efficiency increases so that climbing a hill consumes less energy and your pulse rate should decrease over the beginning of this. I need some encouragement I guess.