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HYBRID TRAINING & HYROX UTILITY

Zone 2 & HYROX Heart Rate Calculator

Calculate your 5 target heart rate zones using the clinical Karvonen Heart Rate Reserve (HRR) formula for Zone 2 aerobic base building and race day pacing.

Physiological Baseline

Tanaka Predicted Max HR: 188 BPM

Age:28 yrs
Resting Heart Rate:60 BPM
Measured at waking rest before caffeine or movement.
Intensity ZoneTarget Band
Zone 1Light Activity / Warm-Up(50% – 60%)

Very easy effort. Great for warm-ups, cool-downs, and easy daily walks. Helps your body recover without feeling tired.

HYROX Strategy: Rest days & easy cool-down after heavy gym sessions

124 – 137 BPM
Zone 2Fat Burning & Base Endurance(60% – 70%)

The sweet spot for burning fat and building heart health. You can comfortably talk in full sentences without losing breath.

HYROX Strategy: Best pace for steady long runs and general stamina

137 – 150 BPM
Zone 3Moderate Cardio / Jogging(70% – 80%)

Faster jogging or cycling speed. Breathing gets deeper, and talking takes a bit of effort. Sustainable for 30 to 60 minutes.

HYROX Strategy: Target running speed between workout stations

150 – 162 BPM
Zone 4Hard Effort / Threshold(80% – 90%)

Fast running or hard interval training. Breathing is heavy, muscles begin to burn, and speaking is limited to 1-2 words.

HYROX Strategy: High-power workout stations (Rowing, SkiErg, Sled Push)

162 – 175 BPM
Zone 5Maximum Sprint / All-Out(90% – 100%)

Full speed sprint. Maximum effort that you can only hold for 30 to 90 seconds before needing to rest.

HYROX Strategy: Final sprint to the finish line

175 – 188 BPM

How to Know You Are in Zone 2 (The “Talk Test”)

When exercising in Zone 2 (137–150 BPM), your body burns mostly body fat for energy. A simple way to check is the talk test: you should be able to speak full sentences comfortably without gasping for breath. Regular Zone 2 cardio builds stamina so you don't run out of energy quickly during tough workouts or sports.

Zone 2 & Cardio Pacing FAQ

Evidence-based guidance on aerobic base training, mitochondrial health, and fat oxidation.

Use the Talk Test. In Zone 2, you should be breathing through your nose or able to speak full sentences comfortably without gasping for breath, but you would not be able to sing. If you can only speak in 2-3 word bursts, you have crossed into Zone 3.
Conditioning & HR Sensor • FitSchool Beta

Automate Live Biometrics & Pacing In FitSchool

FitSchool pairs with Bluetooth HR monitors and smartwatches to alert you when your heart rate drifts out of your target Zone 2 recovery or Zone 4 threshold pacing during workouts.

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