TCX (.tcx)

TCX, Training Center XML, is Garmin's XML format for workouts. Where GPX records a line on a map, TCX records a training session — laps, heart rate, cadence and calories included.

At a glance

History

Garmin introduced TCX in 2007 as part of its Training Center desktop software. It was the answer to a specific shortcoming: GPX describes geometry, and there was nowhere in it to put the sensor data a training device collects. Garmin later moved its devices to the binary FIT format, but TCX remains widely supported as a readable, portable export.

Where it is used

TCX is accepted as an activity upload by Garmin Connect, Strava and TrainingPeaks, and it is the export a lot of older Garmin hardware and Garmin Training Center produce. It is the format to reach for when something needs lap and heart-rate data but cannot read FIT.

Structure

A TCX file is XML rooted in a TrainingCenterDatabase element. The unit is the Activity rather than a bare list of points: each Activity holds Laps, each Lap holds a Track of Trackpoints, and each Trackpoint carries time, position, altitude, distance and — through the ActivityExtension schema — heart rate, running or cycling cadence, speed and power. Lap-level summaries hold total time, distance, calories and maximum values.

How widespread

TCX is the interoperable middle ground of the training world: less compact than FIT, far more expressive than plain GPX, and readable in a text editor. Most fitness platforms still accept it, which makes it a useful fallback when a FIT file is rejected.

RouteConverter support

RouteConverter reads and writes both schema generations, TrainingCenterDatabase v1 and v2. The v2 schema is the one current tools expect; v1 exists for files from the first Training Center releases.

Specifications and documentation

• TrainingCenterDatabase v2 schema
• ActivityExtension v2 schema
• Garmin XML schemas
• Wikipedia: Training Center XML

Related conversions

• GPX to TCX
• TCX to GPX