My HR threshold was automatically calculated at 163 bpm from 98% of 20m at 166 bpm. a couple of weeks later I had a ride of 80m at 161 bpm. I would say my HR threshold should go up, but it didn’t. Is my assumption wrong, or should intervals.icu re-calculate my HR threshold?
Intervals only warns you when it sees a 20min result higher then the last one. You accept or you don’t, it’s up to you to decide if it is legit. Could be false because of spikes or extreme heat for example.
In your case, HR avg is not exceeding the former value, so why should it be increased/recalculated?
Be aware that Intervals will never warn you to dial it down. It’s a good idea to reduce the value at the start of a new season and retest every year.