session · Interactive tool
Heart Rate Training Zones
5-zone training calculator using HRR (Karvonen) or %MHR — Z1 recovery to Z5 VO2max.
Interactive Tool
Heart Rate Training Zones
Calculate 5 training zones from max HR (or age) using HRR (Karvonen) or %MHR methods.
Zone method
Z1 Recovery
Very light · active recovery
50–60%
124–136 BPM
Z2 Aerobic Base
Easy aerobic · long endurance
60–70%
136–149 BPM
Z3 Tempo
Moderate · aerobic capacity
70–80%
149–162 BPM
Z4 Threshold
Hard · lactate threshold
80–90%
162–174 BPM
Z5 VO2max
Maximal · short intervals
90–100%
174–187 BPM
How to use
Wear a chest strap or optical HR monitor. Aim for the zone matched to your session goal — easy runs in Z2, intervals in Z4–Z5.
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