Originally Posted by
gregf83
I often get a high HR over 200 at the start of a ride if my jersey is dry and flapping at all. Once I start to sweat it settles down. If you don't feel anything different when it's up it's likely just a measurement error. Pretty easy to check with your finger on your neck even while running. 200+ is fairly easy to notice. You could also have a condition like Afib but you'd likely feel that.
I usually call anything over 200 a "measurement error" and forget about it. But it's not that simple; cardio for me is 165 and threshold in the 180's, so my 200 heart rate isn't the same as an ordinary 60+ year old seeing a 200 heart rate. It's not necessarily a case of making itself obvious in you-want-to-pass-out fashion.
What's obvious and easy to feel is that subsequent drop. It's my point of feeling warmed up and ready to establish a groove, and the first moment that I feel like I might make it to the finish of whatever I've planned, That's what makes me skeptical that it's all measurement error. It's enough to worry me in idle moments, but not enough to change anything.