Target Heart Rate Training Zones (Karvonen Formula)
Calculate personalized Zone 1 to Zone 5 training heart rates, Heart Rate Reserve (HRR), and Zone 2 fat-burning aerobic thresholds using the Karvonen formula.
Calculated Results
Frequently Asked Questions
Why is the Karvonen formula more accurate than simple percentage of Max HR?
Simple percentage formulas (e.g. 70% of 220-Age) ignore your individual aerobic fitness level. The Karvonen formula calculates Heart Rate Reserve (HRR = Max HR - Resting HR), customizing your target training zones based on your cardiovascular baseline.
Why is Zone 2 training so important for longevity and endurance?
Zone 2 training (60% to 70% HRR) optimizes fat oxidation while keeping blood lactate below 2.0 mmol/L. It stimulates mitochondrial biogenesis, enhances metabolic flexibility, and builds an aerobic engine without central nervous system fatigue.
What is the conversational test in Zone 2 cardio?
In Zone 2, you should be breathing through your nose and capable of speaking full sentences without gasping for breath. If you can only speak 2-3 words between breaths, you have crossed into Zone 3 tempo.
How does Resting Heart Rate indicate cardiovascular fitness?
An endurance athlete often has a Resting Heart Rate between 40 and 55 BPM due to an enlarged left ventricle (increased stroke volume per beat), creating a larger Heart Rate Reserve for athletic performance.