FTHR : Functional Threshold Heart Rate
LoadThe average heart rate you can sustain during one hour of maximal steady effort.
FTHR is the heart-rate equivalent of FTP (power). It lets you define intensity zones in beats per minute when you don't have a power meter. For example, a FTHR of 165 bpm puts your Z2 around 130-145 bpm. Heart rate is influenced by heat, fatigue, and dehydration, making it less stable than power in the short term.
In TriPaced:
In TriPaced, FTP (power) is the main reference for bike zones. FTHR serves as a complementary marker to calibrate run and swim sessions when no power measurement is available.