Last week was a base 'rest week'. This week is E1/E2/E3 type work.
Tuesday, everything normal. Wednesday I spent 5 minutes pushing into a light breeze at cadence over 110 trying to get my heart rate to up from 151 to 158. Instead it WENT DOWN to 143 and stayed there!!???!! What the hell happened? Normally I would assume that kind of response to be a pointer to overtraining, but I'd just come off a rest week!
This morning everything normal again until I burped 5 minutes into the E2 section. Heartrate instantly dropped 10 bpm from 165 to 155!!! And it took nearly three minutes to get it back to 166. I just can't work it out.
Any heartrate geniuses out there might know what's happening?