Optimize for burning
fat or carbs.Free spiroergometry software for VO2max & FatMax testing
Desktop software for real-time metabolic analysis with power meter integration. See exactly when you burn fat, when you burn carbs, and where your thresholds really are. Not estimated. Measured.
Everything you need
Test your metabolism. Train in the right zones. See your progress over time.
Fullscreen Live Dashboard
Desktop software with fullscreen display. VO2, VCO2, RER, heart rate, and power at a glance in real time.
Guided Test Protocols
Step-by-step preparation checklists, individual watt thresholds adapted to the athlete, and automatic stage progression. No more invalid results from poor test setup.
Power Meter & Smart Trainer
Garmin Rally, Favero Assioma, Wahoo KICKR, Tacx and more - live power, cycling dynamics, and torque data directly in your metabolic test. No more manual data merging.
Data Export
Export sessions as CSV or JSON for external analysis and reporting.
Multi-Device Support
Works with Calibre Bio, VO2Master, and more. Connect any BLE or ANT+ heart rate monitor and power meter. Built-in calibration tools for each device.
Free & Local
Free VO2max testing, no account required, no external servers. Your data stays on your machine. Additional protocols and features coming soon.
Download now
Free VO2max testing with full power meter integration. Available for macOS and Windows. No account required.
Compatible with Calibre Bio and other portable VO2 analyzers.