Anaerobic Threshold Calculator

The anaerobic heart rate zone is typically between 80% and 90% of your maximum heart rate. At this intensity, your body produces energy faster than it can use oxygen, leading to lactate buildup. For a 30-year-old with a max HR of 190 BPM, the anaerobic zone is roughly 152–171 BPM.

This calculator uses the Fox & Haskell formula: BPMmax = 220 − age. Your maximum heart rate is then used to calculate each training zone as a percentage of that max. It's the most widely used method for estimating max heart rate from age alone.

Anaerobic threshold is influenced by fitness level, genetics, training history, and overall cardiovascular health. Regular high-intensity interval training (HIIT) can raise your anaerobic threshold over time, allowing you to sustain higher intensities before lactic acid accumulates.

Most people can sustain the anaerobic zone (80–90% of max HR) for only a few minutes at a time. Beyond that, lactate accumulates faster than the body can clear it, leading to fatigue. Elite athletes can push this threshold higher and sustain it longer through training.

Heart rate is the number of times your heart beats per minute (BPM). It reflects how hard your cardiovascular system is working. Resting heart rate for most adults is 60–100 BPM, while maximum heart rate varies by age and fitness.

You can measure heart rate manually by counting pulse beats at the wrist or neck for 15 seconds and multiplying by 4. Alternatively, use a heart rate monitor, fitness tracker, or smartwatch for continuous real-time measurement during exercise.

The five zones are: Recovery (50–60% of max HR), Endurance (60–70%), Aerobic (70–80%), Anaerobic (80–90%), and VO2 Max (90–100%). Each zone targets different physiological adaptations, from fat burning and base fitness to peak performance.

Yes. If you already know your anaerobic threshold BPM from a lab test or fitness assessment, you can enter it in the optional field and the calculator will estimate the expected age corresponding to that threshold based on the Fox & Haskell formula.