Terms of Use

DriftTest · Last updated 1 September 2026

DriftTest is licensed, not sold, under Apple's Standard End User License Agreement: Licensed Application End User License Agreement.

What DriftTest is, and is not

DriftTest estimates the upper limit of your Zone 2 by measuring heart-rate drift across a steady workout you have already recorded. It is a training tool for healthy adults. It is not a medical device, it is not intended to detect, treat or monitor any medical condition, and nothing it shows you is medical advice.

Estimates depend on the quality of the data your watch or heart-rate strap recorded and on the conditions of the workout. Heat, dehydration, poor sleep, caffeine, illness and a hard session the day before all raise drift. Treat a result as one measurement, not a verdict.

Your health

Talk to a doctor before starting or changing an exercise programme, and stop exercising if you feel unwell. You are responsible for the training decisions you make with this app.

Purchases

DriftTest offers a single one-time purchase, sold and processed by Apple. Refunds are handled by Apple under the terms of the App Store.

Privacy

All analysis happens on your device and no health data leaves it. See the Privacy Policy.