Originally Posted by EPOisDope

Mine is defined as "RSR' OR QR PATTERN IN V1 SUGGESTS RIGHT VENTRICULAR CONDUCTION DELAY". The heartbeats are somewhat inconsistent when examined on an EKG, but are shockingly consistent when I wear a heart rate monitor. I don't normally wear a heart rate monitor when riding (I probably should though), but when I do, I almost never find any irregularities, other than my heart rate is always a lot lower than anyone else I know. Resting HR these days is up to the low 40s, LT HR is 150 and Max is 170.

Your training philosophy sounds very similar to mine, in that I'm fearful of LT or above. I do a TON of tempo riding and a fair amount of SST training. For a healthy person, spending a lot of time in L3 wouldn't accomplish much, and might be deemed as counter-productive since it doesn't quite stress the body enough like a good SST / threshold session would, and also doesn't allow the body to recover, but I normally do 2 - 4 hours of "hard tempo" because my heart doesn't seem very willing to go above that. L3 for a few hours definitely hurts! L5 / L6 efforts were never fun even in my racing days, but even less fun when you have arrhythmias when trying to fall asleep that night. I DO think that the extended L3 efforts have really helped improve things such as lactate buffering. Because of that, as you said, I don't HAVE to do as many VO2+ efforts on my rides, and I can recover from a climb pretty quickly. I WISH the heart could handle L4+, but it's simply too much stress on a damaged heart.

I have a hard enough time doing recovery rides on rollers. I'd surely be on the floor if I tried to do a 2-hour tempo / SST ride on them!