Open source · Free forever

Train smarter.
Paddle faster.

The open-source companion app for kayak ergometer athletes and coaches. Live metrics, structured programs and deep workout analysis — right on your Mac or PC.

Download free Explore features

macOS Windows

Companion app made for

KayakFirst Bull Kayak Ergometer

KayakFirst Bull kayak ergometer — the paddle machine KayakFit is built for

KayakFit pairs over Bluetooth with the KayakFirst Bull kayak ergometer.

Shop the Bull at KayakFirst

One session, every metric

Your paddling and your heart rate, together

KayakFit reads the KayakFirst Bull and your heart-rate monitor at the same time and merges both streams into one live session. That combination is the real payoff — you see the effort you put in next to the output you get back, second by second.

  • Live BPM right beside speed, stroke rate & power
  • Time-in-zone and effort-vs-output on one shared axis
  • A single Strava upload with power and heart rate merged
KayakFirst Bull Speed · distance · power Stroke rate · pull force Heart-rate monitor BPM Upload K F KayakFit PACE 2:14 HR 163 PWR 184 Strava Upload activity

Features

Everything you need for every session

From your first stroke to the post-session breakdown — KayakFit keeps every metric in one clean, fast app.

Guided setup & full control

A short first-run wizard connects your KayakFirst Bull over Bluetooth and, optionally, a heart-rate strap. Then tailor heart-rate zones, dashboard metrics, sound cues and Strava uploads to the way you train.

  • Bluetooth pairing in seconds
  • Custom HR zones & dashboard layout
  • Automatic or on-demand Strava upload

Free training with auto-pause

No plan required: start paddling and KayakFit records the session. When you stop, auto-pause freezes the workout so idle time does not dilute your pace or averages. Start again and recording resumes automatically.

  • Automatic pause and hands-free resume
  • Idle time excluded from workout statistics
  • Automatic laps separate each effort

Structured training programs with sound cues

Run interval sessions like 4 × 500 m / 1:00 rest or a 2 km time trial with a live step panel, countdowns and audible cues on every phase change. Each interval becomes its own lap on Strava.

  • Built-in & custom interval presets
  • Audible cues on phase changes
  • Warm-up, work, rest & cooldown tracking

Real-time target coaching

Give any interval a target — a heart-rate zone, pace per 200/500/1000 m, watts or stroke rate — and KayakFit checks your live effort against it. A clear badge tells you On target, Too hard or Too easy, with an audible cue the moment you drift out of range.

  • Targets by HR zone, pace, power or stroke rate
  • Live on-target badge with sound alerts
  • Short grace period keeps it from flickering
KayakFit Workouts window listing planned and free sessions with date and size, plus Open folder, Summary, Save FIT and Upload actions

Your whole training history

Every session is saved and stays open to you. The Workouts screen lists them newest first — re-open any summary, re-export its FIT, re-upload to Strava, or reveal the raw files on disk. Nothing is locked away in a cloud account.

  • Browse & re-open every past session
  • Re-export FIT & re-upload any time
  • Plain CSV + FIT on disk — no lock-in

Deep performance analysis

Both workout modes share synced charts, hover values and heart-rate zones. Their summaries then focus on what matters for that kind of session:

Free workout The uninterrupted session
One continuous effort. Review the overall timeline, session averages, heart-rate zones and lap-level totals without planned phases getting in the way.
Workout plan Every phase and interval
Plan versus execution. See warm-up, every work and rest interval, and cooldown on the charts, then compare each step in the detailed split table.

Built to stay out of your way

Lightweight, cross-platform and completely open — the essentials done right.

Real-time data

Every metric refreshed once a second while you paddle — no lag, no guesswork.

Session recording

Auto-pause, auto-laps and crash recovery capture every effort as CSV and FIT.

Performance analysis

Synced charts, per-lap splits and time-in-zone turn raw data into insight.

Clean interface

A calm, focused layout with light and dark themes that reads at a glance.

Cross-platform

One app, native on both macOS and Windows. No accounts, no cloud lock-in.

Open source & Python

Written in Python, MIT-friendly and fully auditable. Fast, lightweight, and yours to extend.

Open source

Built in the open, in Python

KayakFit is free and open source. The code is written in Python and fully auditable — no telemetry, no accounts, no paywalls. Contributions, issues and feature requests are always welcome.

View on GitHub Download the app Report an issue
  • ✓
    MIT-friendly & freeUse it, fork it, ship it — no strings attached.
  • ✓
    Python poweredReadable, hackable and easy to contribute to.
  • ✓
    Privacy firstYour data stays on your machine. Strava is opt-in.
  • ✓
    Community drivenIssues and feature requests are genuinely appreciated.

macOS

Built for Apple silicon Macs.

Windows

Standalone build — no Python install required.

Get started

Up and paddling in minutes

  1. Download

    Get the free app for macOS or Windows — no account, no sign-up.

  2. Pair

    Connect your KayakFirst Bull and optional heart-rate strap over Bluetooth.

  3. Paddle

    Train with live metrics, then review the session or send it to Strava.

Ready to improve your kayak ergometer training?

KayakFit is free and open source for macOS and Windows. Download the latest release or explore the code, then turn every session into data you can act on.

Download free View on GitHub

Contact

Let’s connect on LinkedIn.

Feel free to reach out for questions, feedback, or collaboration. I’m happy to talk about KayakFit or similar projects.

View my LinkedIn profile