Heart rate curve only after +\_ 15 min correct First 15 min down or out of zone. What is the problem?

Former Member
Former Member

Since a few weeks I have a strange heart rate. The first 10 to 20 minutes the curve is low - or out of zone - but i feel my heart rate is high. Only after 15 minutes it goes up...

Cold cannot be the problem. I had a fenix 5 s plus last year, exercised in cold conditions, then no problem.

can this be fixed? It gives false results