How It Works
RunIntensity reads your Apple Health data and calculates what other apps miss.
Stress-Adjusted Miles
A 5-factor model that accounts for heart rate intensity, terrain, surface type, cumulative fatigue, and environmental stress. See the real cost of every run.
Daily Readiness Score
Composite score from HRV, sleep quality, resting heart rate, and prior workout load. Know if today is a push day or a recovery day.
Weekly SAM Budget
Plan your week with a target training load. Track actual vs. planned as you go with mid-week pacing tips and same-day comparisons.
Free Features
Everything you need to train smarter. No account required.
5-Factor SAM Model
Heart rate intensity, terrain elevation, surface type, cumulative fatigue, and environmental stress combined into one number.
Training Planner
Build periodized plans with phases (base, build, peak, taper, recovery) and milestones for race goals.
Body Soreness Tracker
Tap 36 anatomical regions on a 3D body model to log soreness and spot patterns before they become injuries.
Personal Records
Automatic tracking of distance PRs, fastest paces, and max intensity efforts with 30-day badges.
Research & Science
Read the peer-reviewed studies behind every calculation. No black boxes.
Works with Any Watch
Apple Watch, Garmin, COROS, and more — any workout that syncs to Apple Health flows into RunIntensity automatically. No data left behind.
Shoe Mileage Tracking
Tag the shoes you wore on each run or walk, see total miles per pair, and get a heads-up as you approach your retirement target.
Follow Your Friends
Connect with friends to see their readiness, SAM charts, workout history, and PRs — and cheer each other on with likes and comments on the Bulletin Board. Free.
Apple Watch Companion
Race Pace interval timer, guided workouts, and live metrics on your wrist.
Race Pace Timer
Build custom interval timers with exact H:M:S durations and per-timer repeats. Your last preset is saved automatically for one-tap race starts.
Planned Workouts
Workouts you create on the iPhone sync to the Watch automatically. Each segment has a countdown ring with haptic cues at every transition.
Live Metrics
Heart rate, pace, distance, and elapsed time in real time. Swipe between countdown, controls, and metrics during any workout.
Works With Your Whole Setup
However you record your runs, RunIntensity reads them from Apple Health.
Apple Watch & iPhone
Workouts recorded on your Apple Watch or iPhone import automatically — distance, pace, heart rate, elevation, and GPS routes included.
Garmin, COROS & More
Turn on Apple Health sync in your watch's companion app (Garmin Connect, COROS, and others) and those runs flow straight into RunIntensity.
Automatic De-duplication
The same run recorded by more than one device is detected and merged automatically — no double-counting your training load.
Go Further
Optional subscriptions for AI coaching and team management. Following friends is free.
Coach Brady
Your AI running coach.
- Unlimited AI coaching chat
- Personalized to your readiness & SAM data
- Automatic workout planning
- Weekly review reminders & goal tracking
- Web Coach Dashboard — view your training from any browser
Coach Mode
Full athlete and team management.
- Everything in Coach Brady
- Manage unlimited athletes & groups
- Create phases, milestones & plans
- Assign planned workouts
- Group comparison charts
- Push notifications on athlete activity
- Web Coach Dashboard — manage from any browser
Privacy First
All core calculations happen on your device. RunIntensity reads Apple Health data but never writes to it. Friends and Coach modes sync only the data you choose to share to a secure Azure backend. No ads. No analytics SDKs in the app. No tracking.
Read the full Privacy Policy →Requires iPhone with iOS 17.0 or later. Apple Watch (watchOS 10.0 or later) for companion app. Import running workouts via Apple Health. Sign in with Apple required for Friends Mode, Coach Brady, Coach Mode, and connections.