quack wrote:
It probably means that what you are used to being "tempo pace" is too fast. This is one of those cases where "just because you can go faster, doesn't mean it is beneficial for you if you do". This is pretty common for people just getting a heart rate monitor, and it feels weird at first... but it's beneficial
I decided to start using my HR monitor for tempo/threshold workouts because when doing them based on pace from race results they always felt too hard but just kept doing them thinking it would benefit me. It has had the opposite effect though.
With the HR monitor the pace is slower than I have run these workouts and it's difficult to get in the mindset that the effort is correct.