Hi all, 3rd block (2nd interval) heart rate spike not drift. Not HRM strap sensor error as I have a second wrist HRM that matched the reading. Heart rate trend/characteristic very different to previous intervals which grew progressively through the interval.
Should I worry?
I backed it down from a perspective of caution - I didn’t ‘feel’ it but was alarmed by the value.
Thanks for your thoughts,
Richard.
Hey @richard2747,
What’s your typical max HR? Did anything else happen that may have caused your HR to increase (change of position on the bike, take a sip of water, etc.)?
Your heart is nothing to mess around with, so if this concerns you, I’d definitely mention it to your doctor. There’s no harm in being a bit cautious. 
context of what your resting is, best max would help
Also where are you in your training? If you are near a peak a highly responsive heart rate is a sign of improved fitness and faster response - so might be a sign it’s working
I know for me the last two weeks before a peak my HR is all over the place
Max for V02 training is 170ish. Nothing else to noted happened.
I’m 48 years old with a resting HR of 48bpm. Interval training for more than 10 years, have seen this perhaps 3 times before. Sleep this week hasn’t been good due to work commitments, average 5 hrs rather than 6/7.
thats a super low RHR - so this isn’t an all time max, but doesn’t match the workout intesnity if I understand correctly.
I’d still wonder where you are progression wise in your plan and peak - but I see the intial concern you had.
FWIW I did have a friend experince similar symptoms years back - he too had insanely low HRs compared to myself. He did uncover a lingering cardiac issue through this but nothing life threatening.
As the first reply stated a doctor call might be a source of comfort even if it turns out to be nothing
