See your fitness —
and where it’s going.

Adaptive Training is a free, local-first training app for cyclists and runners. Import your rides, see your fitness modelled out to your target events, and dig into any ride in detail. It adjusts your plan as your day-to-day training and recovery change. Your data stays local and private — no account, no subscription.

Try the live demo → Download
free · no account or subscription local-first FIT / GPX / TCX import CP / W′ · W′bal fitness, fatigue & form export workouts to Zwift · Garmin · Wahoo sync plan + races to intervals.icu
Adaptive Training fitness dashboard

Free browser tools

Two standalone calculators that run entirely in your browser — no account, no upload, nothing to install.

Running — Critical Velocity

Drop in your best recent times and get your critical velocity and D′, what you're ready to race with honest uncertainty, and a sandbox to model a race pace.

Open the calculator →

Cycling — Bike Split

Drop in a route and your numbers and get the power to hold over every climb, descent, and headwind, with a W′ battery — then export it to Zwift or your head unit.

Open Bike Split →

What it does

The usual reporting, plus a look at where your form is heading.

See where your form is heading

Fitness, fatigue, and form charted over time — then modelled forward to your target events, with a wellness overlay (sleep, fatigue, soreness, motivation) so today's session is a decision, not a guess.

Know your engine

Critical Power and W′ straight from your own rides, with your anaerobic battery drawn right under the power curve — so you can see how much you've got and exactly when it runs out.

Find free speed

Measure your aerodynamic drag (CdA) and rolling resistance (Crr) from your own rides with the Chung virtual-elevation method — no wind tunnel, no sensors. A paid headline feature on other platforms; here it's free, and it feeds straight into Bike Split.

Dig into any ride

Per-ride streams, route map, and a full lap editor — create and delete splits, undo/redo, hover any lap for its stats, or read them all in a table.

Bring in every ride

Drop in a FIT, GPX, or TCX export from any head unit. Power rides get full load, streams, and analysis; no-power activities still get a sensible, defensible estimate.

Train on any device

Send the day's session — or any workout — to Zwift, Garmin, Wahoo, or TrainerRoad as .zwo, .erg, .mrc, or .fit. (We are not affiliated with any third-party applications)

Your plan on every screen

Connect intervals.icu and your whole plan and races stay on your calendar — pushed on to Garmin, Wahoo, and Zwift (even Apple TV) automatically. (We are not affiliated with intervals.icu)

Your data, never locked in

Everything lives in a single SQLite file you own — query it, chart it, and export it all any time with the built-in explorer. Nothing is locked away.

How the numbers are computed →

Your data is yours

Local-first by design.
  • Stored locally in a single SQLite file you own.
  • Exportable any time — full database, open format, no lock-in.
  • Works with no subscription or service dependencies — it runs on your own machine, in an open file format.
  • No account required to run it yourself.

How the demo works. The hosted demo gives every visitor a private, throwaway copy of a synthetic athlete's data. Click around, edit anything, import a file — nothing persists and nothing is shared. Hit Reset any time for a fresh copy.

To use it for real, run it locally and import your own rides.

Note: this application is a public beta. Adaptive Training is being built and iterated on. The reporting features are solid; the predictive models are still being validated against what's already out there before any strong claims are made. Try it, break it, and tell us what's off.