Yesterday I went to the gym and did a 55 min. spinning video for strength...lots of standing and seated climb power segments. This was my 6th day out of the week so I'm actually being consistent and working. A lot of that time I was working in the 130-136 bpm range. Based on estimated max HR I had come up with I was hitting 90%. I'm pretty sure that's not accurate at all as has been said. The first sign of real duress for me is always lactic acid burn in my quads around my knee area. But, what I got yesterday for burn was not all that bad. Really looking forward to the testing and development of a program. And, really appreciate everyone's contribution here. I've learned a lot.