ZWO ERG MRC FIT File Builder

ZWO ERG MRC FIT File Builder is the fastest and most flexible way to create structured cycling training files on your iPhone or iPad. Whether you train with Zwift, TrainerRoad, Garmin, Wahoo or any other platform, this app puts the power of custom workout creation in your hands and exports directly to the format you need.

Build any workout from scratch using a clean, intuitive interface. Add steady-state intervals, warm-ups, cool-downs, ramps, free-ride blocks and full interval groups with just a few taps. Set each segment by wattage or as a percentage of your FTP, and the app handles all the power fraction maths for you so you never have to think about it.

Once your workout is built, export it in whichever format your platform supports. Choose from ZWO for Zwift, ERG for TrainerRoad and compatible apps, MRC for older cycling software, or FIT for Garmin devices and platforms that accept the FIT protocol. The format picker sits right at the top of your workout library and remembers your last choice, so exporting is always one tap away.

You can also import existing ZWO files and edit them inside the app. Adjust power targets, tweak segment durations, reorder intervals, or completely rebuild a session around your current FTP. Every edit is reflected in the exported file accurately, whether you change power directly in a segment or use the watt offset stepper to shift an entire workout up or down.

Your FTP is central to everything. Set it once in settings and the app uses it as the reference for all power calculations across every export format. Update your FTP and your workout power fractions update automatically, keeping every file you export precisely calibrated to where your fitness is right now.

The workout library keeps all your creations organised in one place. Swipe to delete, tap to edit, or hit the export button on any workout to share the file instantly via the standard iOS share sheet. Files can go straight to cloud storage, be AirDropped to another device, emailed, or opened in any compatible app.

ZWO ERG MRC FIT File Builder is designed for cyclists who want to take ownership of their training without being locked into a single platform. It does one thing exceptionally well: it builds structured training files and gets them into your hands in the format you need, quickly and accurately.

ZWO ERG MRC FIT File Builder is an independent app and is not affiliated with, endorsed by, or associated with Zwift, TrainerRoad, Garmin, Wahoo, or any other third-party brand or platform. All trademarks are the property of their respective owners.