165 BPM
Heart Rate
Train by
Feel
Power shows the work. Heart rate shows the cost. Calculate your 5 HR zones for smarter training.
Zone Breakdown
Each zone targets different physiological adaptations
Z1
Recovery
50-60% Max HR
Active recovery, warmup/cooldown
Z2
Endurance
60-70% Max HR
Aerobic base building, fat burning
Z3
Tempo
70-80% Max HR
Comfortably hard, muscular endurance
Z4
Threshold
80-90% Max HR
Sustained hard efforts, lactate threshold
Z5
Max
90-100% Max HR
VO2 max intervals, all-out efforts