I've been running about 60 miles per week for several months by feel at a quality aerobic pace; no strides, repeats or sprints.
I'm giving HR training a try and attempted Hadd's max heart rate method last week.
I ran 800 meters hard but had to be careful as I felt that something might pull at any second, jogged ninety seconds then took off hard to complete the 400 meter portion but had to stop after 100 meters when a hamstring started to cramp.
Over the next several minutes I ran very hard up two steep hills for about2-3 minutes until I had to stop and walk, feeling maxed out.
My heart rate on the hills never went above what it reached during the 800 meter portion on the track and the pace on the track felt only like a hard 5k race effort.
Is it possible that I can't reach my max HR until I've done some speed training that will allow me to push legs harder, even though I was spent at the end of the hill portions?