Driftline Analytics
The science layer missing from every wearable.
TrueZone is the first unified model of human physiology. Three parameters extracted from ordinary heart rate data. Every fitness and metabolic metric derived. No lab required.
Try it — adjust the three parameters
Derived outputs
The Model
Three parameters. Everything derived.
TrueZone fits a physiological ODE to your heart rate signal using Bayesian accumulation. From three converged parameters, the entire fitness and metabolic profile follows.
Endurance
The first direct measure of aerobic endurance. Reflects fat-oxidation capacity, mitochondrial density, and slow-twitch fiber ratio. Scale: 0–100%.
Max Speed
Maximum neuromuscular speed capacity. Derived from the model's characteristic speed parameter. Determines the top of the intensity scale.
HR Peak
Model-predicted maximum heart rate, determined geometrically from heart rate kinetics. No maximal test needed. Anchors the P-scale.
Derived from E, V, and P
Applications
One model. Every sport.
The same three-parameter architecture fits running, cycling, and team sports without sport-specific tuning. Each application page tells the full story: problem, solution, validation.
Beyond Sport
Metabolic health from heart rate.
Endurance (E) is the strongest wearable-accessible predictor of cardiorespiratory fitness—itself the strongest predictor of all-cause mortality. TrueZone extends into metabolic zones, fat oxidation tracking, and the Metabolic Fitness Index (MFI).
Metabolic Fitness Index
Quantifies metabolic flexibility, fat oxidation efficiency, and glucose response.
Metabolic Zones
Track substrate strain and metabolic inflexibility in obesity, ageing, and insulin resistance.
Energy Expenditure
Separates basal, activity, and feeding components from HR analytics.
Energy Intake
Pilot-scale modelling of postprandial thermic effect from HR signal dynamics.
“Driftline's work lays the groundwork for next-generation metabolic monitoring solutions that support healthier aging and improved population health.”
Willum Thor Thorsson
Former Minister of Health, Iceland (2021–2024)
For Platform Partners
Today's wearables measure heart rate with millisecond precision. They still can't read what it means.
Across Garmin, Apple, WHOOP, Polar, COROS, and every other platform, the science layer is the same: a VO₂max estimate, fixed percentage zones, and heuristic recovery scores. No individualized thresholds. No endurance modelling. No metabolic insight. TrueZone is the missing layer—an SDK that turns existing heart rate data into real physiology.