Polar Flow is the official free companion app for all Polar smartwatches and fitness devices. Developed by Polar Electro Oy — a Finnish company that invented the world's first wireless heart rate monitor in 1982 — the Polar Flow app transforms raw sensor data into deep, actionable health and performance insights. With over 5 million downloads on Google Play and a 4.6-star rating on the App Store, Polar Flow is one of the most trusted training analysis platforms for serious athletes and everyday fitness users alike.
What Is the Polar Flow App?
Polar Flow is a free sports, fitness, and health companion app that connects to your Polar device via Bluetooth and syncs your workout, activity, and sleep data in real time. Every training session is logged with full detail — heart rate zones, pace, altitude, GPS route, power, and cadence — and displayed in a clean, easy-to-read interface. Beyond workouts, the app provides 24/7 activity tracking, advanced sleep analysis, and recovery metrics that adapt to your personal fitness baseline over 28 days.
The Polar Flow app is available on iOS (17.0+), Android (8.0+), and as a full-featured web service at flow.polar.com — giving you a desktop view of your training diary, reports, and sport profile editor.
How Does Polar Flow Work?
After pairing your Polar device with the app over Bluetooth, every activity, sleep session, and daily movement is synced automatically. The app uses scientifically validated algorithms to process your biometric data and produces five core insight areas:
-
Training Analysis — Detailed post-workout review with heart rate graphs, training load (TRIMP), GPS route playback, and sport-specific metrics. Running sessions include Running Index — an aerobic fitness score that predicts your race performance times for 5K through marathon.
-
Sleep Plus Stages™ — Automatic sleep stage detection (light, deep, REM) validated against polysomnography (clinical gold standard). You receive a Sleep Score (1–100) each morning covering amount, solidity, and regeneration.
-
Nightly Recharge™ — An overnight recovery metric combining your ANS Charge (autonomic nervous system recovery via HRV and breathing rate) and Sleep Charge. After three nights of data, the app delivers personalized daily tips based on your readiness level.
-
Training Load Pro™ — Tracks your training load across three dimensions: Cardio Load (TRIMP-based), Muscle Load (running and cycling power), and Perceived Load (RPE 1–10). The Cardio Load Status view shows your 14-day strain-to-tolerance ratio.
-
FitSpark™ Daily Training Guide — Up to four ready-made daily workout suggestions (cardio, strength, supportive) tailored to your fitness level and Nightly Recharge status. Updates after each session, at midnight, and upon waking.
Is Polar Flow Free?
Yes — Polar Flow is completely free to download and use. All core features including training analysis, sleep tracking, Nightly Recharge™, Training Load Pro™, FitSpark™, Running Index, and Strava/Apple Health integration require no subscription or payment. The app does offer optional in-app purchases, but the full scientific coaching experience is available at no cost. This is a key differentiator from competitors like WHOOP ($199–$359/year subscription required).
Key Features of Polar Flow
Activity Tracking
Monitor daily steps, calories burned, distance, and 24/7 continuous heart rate from your wrist. Set personalized daily activity goals and track progress week over week.
Running Index & Running Program
After every GPS run, Polar Flow calculates your Running Index — an aerobic fitness score that improves as your running economy develops. The Polar Running Program (via the web service) generates a free adaptive training plan for 5K, 10K, half marathon, or marathon based on your current fitness level and adjusts automatically as you progress.
SleepWise™
Uses biomathematical modeling of your recent sleep patterns to predict your daytime alertness windows — showing when you'll be at peak focus and when a nap would help most. Requires five sleep measurements in the last seven days.
Serene™ Guided Breathing
A six-breaths-per-minute guided deep breathing exercise that uses real-time biofeedback to measure heart-breathing synchronization. The watch provides vibration-guided breathing cycles with results shown across three serenity zones.
FuelWise™ Smart Fueling
For endurance athletes: calculates carbohydrate needs mid-workout using Energy Sources data (fat vs. carb utilization), sends smart carb reminders, and tracks hydration intervals during long sessions.
170+ Sport Profiles
Choose from over 170 sport profiles including running, cycling, swimming, strength training, yoga, calisthenics, fitness racing, rucking, and ski machine (added December 2025). Each profile has fully customizable training views and data screens.
Device & Profile Management
Customize your Polar watch face, widgets, notifications, sport profiles, and training targets directly from the app. Manage up to 20 sport profiles on the watch simultaneously (unlimited in the web service).
Polar Flow Integrations
Connecting Polar Flow to Strava is done in one step: go to Settings → Partners in the Flow web service and authorize your Strava account. GPS workouts will then auto-sync to Strava after every training session.
Connecting Polar Flow to Apple Health is configured in the Flow app's General Settings. Synced data includes active energy, heart rate, resting energy, sleep stages, steps, weight, and workout sessions.
Other supported integrations:
- TrainingPeaks (bidirectional — sessions and training plans)
- komoot (bidirectional — planned routes and completed tours)
- Google Fit / Health Connect
- Adidas Running
- Nike Run Club, MyFitnessPal
Polar Flow vs. Polar Beat — What's the Difference?
| Polar Flow | Polar Beat | |
|---|---|---|
| Purpose | Full companion app for Polar watches | Standalone workout app (no Polar watch required) |
| Hardware | Requires a Polar device | Works with Polar H10/H9/Verity Sense sensors or phone camera |
| Training Analysis | Deep post-workout analysis + diary | Basic workout recording |
| Sleep Tracking | Yes (Sleep Plus Stages™) | No |
| Recovery | Nightly Recharge™, Training Load Pro™ | No |
| GPS | Via Polar watch | Via phone GPS |
Use Polar Flow if you own a Polar watch. Use Polar Beat if you only have a Polar heart rate sensor and want to record workouts from your phone.
Polar Flow for Coach
Polar Flow for Coach (available free at flow.polar.com/coach) is a professional coaching platform that allows personal trainers and coaches to:
- Monitor multiple athletes' training data in real time
- Create individualized training plans and seasonal periodization
- Group athletes by team or category
- View sleep, recovery, and training load data for each athlete
Athletes connect by accepting a coach invitation through the web service — no additional hardware is required.
Polar Flow Web Service
The Polar Flow web service at flow.polar.com offers a richer desktop experience including:
- Diary — full training calendar with daily, weekly, and monthly views
- Reports — multi-sport analytics filtered by time period
- Explore — browse shared GPS routes on a world map
- Data Export — TCX format for workouts, CSV for HRV data
- Full Data Download — JSON/XML export of all personal data at account.polar.com
- Sport Profile Editor — full customization of training views and data fields
