Thanks Scott and Scott.
You confirmed what I was starting to suspect about wrist-based HR monitors.
I noticed the decoupling at around 2:15 mark. The top was noticeably steeper and deeper snow, so we dropped our pace to keep breathing in check.
I reread the articles on Breathe Intensity Monitoring and have a follow-up question given your comments that ventilation can change with fat adaptation and fatigue: Assuming I had good data from a chest strap, should I assume breathing or heart rate is the better marker AeT that I should be using for my uphill zone 1 hikes?
Thanks,
Jim