intervals-ftp-update

Keeps the FTP on your intervals.icu profile in sync with the eFTP it estimates from your rides — without letting a quiet training block quietly drag your FTP down with it.

uvx intervals-ftp-update --api-key=YOUR_KEY

That is the whole install. uvx fetches it, runs it, and throws it away again. No athlete id needed — the key already identifies you.

What it looks like

The Change column is the whole point: +8 means a ride actually pushed the eFTP up that day, decay means the number drifted down on its own because an older peak aged out. Only the former counts as evidence.

Why not just copy the eFTP across

The eFTP only moves up when a genuine best effort pushes it there. After that it decays on its own, because the peak that produced it slowly ages out of the 90-day window. Nothing about you got slower — the number just ran out of evidence.

A naive "set FTP to eFTP" job follows that decay down and quietly rewrites your training load with it. So this tool treats the two directions differently:

Everything else is reported and left alone.

Why this matters: intervals.icu computes training load (TSS) from your recorded FTP, not the eFTP. Set it too low and every ride looks harder than it was, your CTL climbs, and you think you are fitter than you are. Too high and the reverse.

Usage

uvx intervals-ftp-update --api-key=KEY       # the key on its own is enough
uvx intervals-ftp-update                     # or take it from the environment / .env
uvx intervals-ftp-update --dry-run           # show the proposal, never write
uvx intervals-ftp-update --yes               # write without asking

# Only if you need to target someone other than the key's owner:
uvx intervals-ftp-update --api-key=KEY --athlete-id=123456

Nothing is written without a confirmation prompt unless you pass --yes.

Credentials

The API key sits at the bottom of https://intervals.icu/settings. Provide it by flag, by environment variable, or in a .env file next to where you run it:

INTERVALS_ICU_API_KEY=your_key_here
INTERVALS_ICU_ATHLETE_ID=123456

INTERVALS_ICU_ATHLETE_ID is optional — left out, the tool acts on whoever owns the key. If you do pass it, digits only: the web UI writes it as i123456 but the API only accepts 123456. A leading i is stripped for you.

Options

What it does not touch

Changing your FTP does not rewrite past activities. Every ride on intervals.icu stores the FTP it was computed with, so your fitness curve stays intact. This tool never calls the sport-settings/{id}/apply endpoint, which is the one that would retroactively recompute your history.

HR zones are left alone too — they hang off your LTHR, not your FTP.

Development

just test       # run the suite with coverage
just coverage   # the same, as a browsable HTML report
just check      # dry run against your own account
just update     # run for real, with the confirmation prompt
just build      # build the distribution

Releases are cut by tagging:

git tag v0.1.0 && git push --tags

CI runs the tests, refuses a tag that disagrees with the version in pyproject.toml, and publishes to PyPI through Trusted Publishing — no API token is stored in the repository.

License

MIT