Training Question: Why is my HR staying so low?
I trained all winter doing indoor intervals on a trainer, running my HR way up (150 to 160... I'm 64) on a regular basis. I felt great and was strong in my earlier rides outdoors. Now after about six weeks riding outside and putting on a lot of miles (for me) I'm just not getting the HR up there for some reason. My rides aren't any slower in terms of average speed than normal and I don't feel all that weak but I rarely even hit "tempo" pace above 130 or so, and I have done entire 90 minute + rides in that zone before.
I'm in an endurance phase building up to a weeklong supported tour next month but still... I'd like to get into zone four or five once in awhile. I'm not training more than five days a week and my rides usually don't exceed three hours. My lungs feel fine but my rides seem to be more limited by leg fatigue than by oxygen delivery. Am I somehow overtrained and needing a break? Should I replace my HR monitor battery? This is a little weird.
Advice is welcome.