I have tested my heart rate on a treadmill on several occasions, it doesn't go above 182 and from 170 or so it gets harder and harder edging up a single beat at a time. I'm 42, so its about average if using the calc 220-age.
I'm trying to be more efficient at training and i bought Daniels Running Formula which is brilliant. I have no problem with long runs, reps or thresholds, but i'm struggling with the intervals. At my vdot of 39 i should be able to do 1km intervals at 12.5kph and get up to vo2max for 3 of the 5 ish minutes it takes to do these intervals, but i can't. I want to stress my oxygen capacity but i just get too ragged and tired at over 95% heart rate. If i run slower it takes longer to arrive at the same problem. How do i spend time at 100% heart rate?