Question from Rob Worrell: “My seasonal goal was an 11mile hill climb near my home at the conclusion of the summer. In interval training I once hit 182BPM (I am 39 Years old), but most of my intervals are around 160-170BPM. In the MTB hill climb race (seasonal goal), I averaged 173BPM for a 1:05:30 race time. This seems like my threshold is really close to my max of 182BPM? I lost by 6 minutes or 33 seconds per mile. Do I need to increase my threshold even higher? Or how do I get more power at the same threshold?”
Threshold heart rate and threshold watts are two different terms. Your best average heart rate for a one hour event is probably very close to your performance in the MTB hill climb race you mention. This means that on that specific day, you delivered an optimal performance.
No training = Lower threshold power
If you didn’t train the last 12 weeks before this event, you would probably still be able to maintain an average heart rate close to 173bpm, but there is no doubt that your finishing time will be significantly slower. This is because your threshold watts at the same heart rate are much lower when you haven’t trained.
More training = Higher threshold power
Thus, when you train consistently and do some good workouts, your threshold power output will increase, but your threshold heart will very likely remain at the same level. You are close to the limit of how much you can push your average heart rate, but that is in fact uninteresting. There is a huge aerobic potential waiting for you, when you start to work focused on your threshold power. In theory, there is no limitation on how far you can raise you power output.