3 to 4 years ago, my HR on long runs (90mins+) would easily be in the 140 to 150 range. I was taking iron tablets at the time (~60 mg Fe daily).
Now, on these same runs, my HR is between 120 to 130 for the same perceived effort. I have not taken iron tablets in over 2 years now.
Any suggestions for this? I try to eat red meat most days instead of taking the tablets.
Thanks