I had my last sprint triathlon of the season today, and for the first time (and won't be the last!) I wore my heart rate monitor.
On the bike, I was feeling good, and actually had an avg heart rate in zone 5b. I was pushing but felt very comfortable. When I hit the run, I just couldn't get my legs turning over. 7 days before, I completed a 10k run at an avg pace of 6:34 m/miles, with an avergae heart rate of 182 bpm. Today i averaged 7:07 min/miles for the 5k run of the triathlon. My avg heart rate for the run (170bpm) was 10 beats below my functional threshold heart rate of 182bmp.
Two things stand out at me: first, I was comfortably cycling above my cycling FThr. Second, I couldn't elevate my heart rate to threshold in the run. I just didn't have the energy.
On a side note, the majority of my training this year has been aerobic, zone 2, as I completed an Iron distance event in July. Your books were paramount to my success!
Is there a simple answer to this?
Appreciate the time if you or one of you coaches could answer my email.
"I just didn't have the energy" is really the key point here--not your heart rate. The issue really isn't how high or low your HR was, but rather your speed--regardless of HR. Train to improve that (intervals, hills, fartlek, etc along with your z2 training) while placing less emphasis on HR. It's merely an indicator of how hard the engine is working. It doesn't regulate performance at all. A related, recent tweet of mine went something like this: "Being concerned with how high your HR is relative to sport performance is like telling your auto mechanic that your car is going too slowly because the tachometer is reading low." Train your engine--the muscular system--for power/speed and appropriate pacing while getting adequate recovery (rest and nutrition) and your performance will likely improve. Good luck with your next race!