Lots of good information here, but I still have questions. I've owned the John Parker book on HR training for years. Every time I pull it out to use it, I quit again after two or three days because, at <70%, I'm walking. Really? Even the 12 week program for intermediate runners has be doing a "jog" at 65% - that's a slow, slow walk for me. My HR monitor is beeping every 30-50 steps and driving me crazy.
So what's the problem? Is my heart stronger than average and should I bump up my numbers a bit? Or is my heart not as strong as I think and I just need to get used to walking?