The unified model
of human metabolism.
Presenting TrueZone — a single validated system connecting endurance, power, and metabolic health, transforming heart rate into true physiology.
Endurance quantified for the first time
What endurance unlocks.
By solving endurance — the most fundamental and elusive variable in exercise physiology — our model unlocks the full metabolic profile from heart rate alone.
Endurance
The first true measure of aerobic endurance on a scale of 0–100%, derived from your metabolic threshold pattern.
PrimeScore
A single number capturing your total functional capacity across the power–endurance spectrum, comparable across individuals and disciplines.
Five exercise thresholds
Fatmax, lactate threshold, VO₂max, anaerobic threshold, and max power — the complete threshold ladder.
VO₂max
Lab-grade maximum oxygen uptake estimate without a mask or an all-out effort.
Fat oxidation
Peak fat burn rate and the exact speed at which it occurs — metrics that normally require indirect calorimetry.
Training zones & paces
Nine individualized training zones with target paces, anchored to your actual metabolic thresholds.
Race predictions
Predicted best times for 11 distances from 100m to the marathon, based on your threshold profile.
Metabolic fitness
Resting metabolic rate, fuel mileage, and body composition estimates from heart rate kinetics.
Heart rate zones
Threshold-aligned heart rate zones that reflect your actual physiology, not generic percentage formulas.
Our mission
Unlocking a great untapped potential. Your metabolic fitness is encoded in your heart rate. We have discovered the key to unlock it and we're bringing it to wearables everywhere.
Accessible to everyone
Lab-grade analytics without the lab.
Traditional, high-level fitness testing requires expensive lab equipment and leaves you lying on the floor, gasping for air. With Driftline, you get even more accurate results, requiring only minimal effort and a regular fitness tracker.
Tested & verified
Results you can trust.
Built for both personal and professional needs, our analytics provide precise and dependable insights you can count on. To learn more, check out our validation studies.
Lab-Tested Reliability
Our method has been validated in lab settings, ensuring reliable results.
High-Grade Precision
Experience gold-standard accuracy without the need for costly equipment.
Patented Technology
Our method is patented, unique and unmatched anywhere else.
Big insights, small package
Fast, lightweight and powerful. Real-time insights, post-workout metrics and long-term trends available on device and in the cloud.