Help, setup, and answers.
Riven is an Apple Watch and iPhone app that scores every set of resistance training from 0 to 100 so you know — in real time — when you've actually reached muscle failure. It uses the watch's motion sensor and heart-rate sensor. No barbell clip, no chest strap, no extra hardware.
Getting started
- Install Riven from the App Store on your iPhone. The watchOS app installs automatically if your Apple Watch is paired.
- Open Riven on iPhone and finish onboarding (subscription choice, HealthKit permissions for heart rate and workout sessions, motion permission).
- On your Apple Watch, open Riven, tap Start Workout, pick or auto-detect your first exercise, and lift. Tap End Set when the set is done — the failure score appears immediately.
Frequently asked questions
Which Apple Watch do I need?
Apple Watch Series 6 or later, running watchOS 10 or later, paired with an iPhone running iOS 17 or later. Series 6 is the minimum because Riven samples motion at 100 Hz and needs the optical heart-rate sensor available on Series 6 and up.
Does Riven work on every exercise?
Riven auto-detects 30+ common resistance-training movements — bench press, squat, deadlift, overhead press, rows, pull-downs, curls, lateral raises, leg press, hip thrust, and more. For any exercise that isn't on the auto-detect list, you can pick it manually from the exercise picker. The failure score works on machines, cables, dumbbells, barbells, and bodyweight — anywhere the wrist is moving with the load.
How accurate is the failure score?
The score combines wrist-motion velocity loss with heart-rate dynamics and is calibrated against labeled gym sets. It works best when the watch is snug to your wrist (a loose watch adds noise) and when you wear the watch on the side where the working muscle's load is most clearly transmitted (typically the dominant side for unilateral work). Riven gives you a fitness-training signal, not a medical assessment.
Will my workouts drain the watch battery?
A typical 60-minute strength session uses roughly 10–15% of an Apple Watch Series 8 / 9 / 10 battery — about the same as a Workout app session, because Riven runs inside the standard HKWorkoutSession wrapper. Ultra users see less. Watch faces with always-on display add a few percent.
How do I export my workout data?
On iPhone, open Settings → Data → Export workouts. Riven generates a ZIP of CSVs (one per workout) you can save, AirDrop, or email. You retain full ownership of this data.
How do I cancel or change my subscription?
Subscriptions are billed by Apple, not by Riven. To manage, change, or cancel a subscription, open the App Store on your iPhone, tap your profile picture, tap Subscriptions, and pick Riven. Cancelling stops the next renewal; you keep paid features until the end of the current period. Refund requests go through reportaproblem.apple.com.
How do I delete my account?
On iPhone, open Settings → Account → Delete account. This permanently removes your local profile and signs you out of Sign in with Apple. To also erase any anonymized workout uploads tied to your device's identifier, email [email protected] from the address you'd like us to confirm the deletion to — we complete erasure within 30 days, in line with the Privacy Policy.
The watch app isn't installing on my Apple Watch.
Open the Watch app on your iPhone, scroll to Available Apps, and tap Install next to Riven. If it doesn't appear, force-quit the App Store and Watch apps, then reboot the watch. If it still doesn't appear, email [email protected] with your watch model and watchOS version and we'll dig in.
My exercise wasn't auto-detected. What now?
Tap Pick exercise on the watch and choose it from the list. After each set, Riven asks you to confirm or correct the detected exercise and rep count — the corrections improve detection for future sets.
Contact
Email [email protected]. We read every message. Please include your iPhone model, iOS version, Apple Watch model, watchOS version, and a description of what you were doing when the issue occurred.
For privacy questions or data-deletion requests, email [email protected].