Karvonen Heart Rate Zones
Heart rate reserve (HRR) & 5 exact target training zones.
Max HR estimated as 220 − age. Take resting HR first thing in the morning.
Heart Rate Reserve
130 BPM
Max HR: 190 BPM
Your 5 Training Zones
Z1 · Recuperation125–13850–60%
Z2 · Endurance138–15160–70%
Z3 · Tempo151–16470–80%
Z4 · Threshold164–17780–90%
Z5 · Max Effort177–19090–100%
Zone 2 builds aerobic base and fat oxidation. Z4–Z5 build lactate tolerance. Easy days easy, hard days hard.
Did you know?
The 220 − age max HR formula is a generalisation — real max HR varies by up to ±20 BPM between people of the same age.
Formula
Target HR = ((Max HR − Rest HR) × Intensity%) + Rest HR
FAQs
Why Zone 2?
60–70% HRR builds mitochondrial efficiency — the foundation of endurance.