Fit File Forge – Free AI Tool for Instant Garmin Structured Workouts

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Fit File Forge – Free AI Tool for Instant Garmin Structured Workouts

Hi Intervals.icu community,

I’m Caleb Wetherell, the developer behind Fit File Forge, a completely free tool I built to make creating structured workouts for Garmin watches as easy as typing a sentence.

Like many of you, I love Intervals.icu—its analytics, planning tools, and text-based workout builder are fantastic and far superior to Garmin Connect’s native interface. However, even Intervals.icu’s builder requires learning the syntax and formatting steps correctly. I wanted something even faster for quick, one-off sessions or when I just have a specific workout idea in mind.

That’s why I created Fit File Forge:

How it works

  • Describe your workout in plain English (e.g., “10 min warm-up easy, 5x3 min at threshold pace with 2 min recovery jog, 10 min cool-down”).
  • The AI generates a fully structured, Garmin-compatible workout in 10–15 seconds.
  • One-click send to your Garmin Connect account → syncs to your watch like any native workout.

Key features

  • 100% free (no paywalls or premium tiers for core functionality)
  • Supports running, cycling (including bricks), swimming, and strength
  • Uses your personal zones (pace/power/HR), cadence targets, etc., for accurate steps
  • Schedule workouts for specific dates directly in your Garmin calendar
  • AI Coach chat for brainstorming or refining ideas
  • Personal vault to save and reuse your favorites
  • Shareable workout links

It’s designed to complement platforms like Intervals.icu perfectly: keep using Intervals for your training plans, periodization, and deep analytics, but use Fit File Forge when you want to create a custom session in seconds without touching syntax.

The tool launched recently and has gotten great feedback from the Garmin community on Reddit (r/Garmin thread with lots of happy users and feature requests I’ve been adding quickly).

I’ve also added a Coach feature that let’s you work with an AI Coach that will generate workouts ready fro Garmin based on your conversation. Not much different than using ChatGPT as a coach, except it skips you the step of having to manually create the workout in Garmin Connect.

What it’s not: Fit File Forge does not import data from anywhere. You’re in complete control of the workouts generated. For power users of Intervals.icu, I think this is actually a feature - you aren’t bogged down by suggested workouts you’ll never do. You decide. You can talk to the coach and share how you’re feeling, what goals you have this week, etc, get some ideas, and pick what to do.

I’d love for some of you power users here to try it out and let me know what you think—feature suggestions are always welcome!

Link: https://www.fitfileforge.com/

Thanks,
Caleb Wetherell
(Developer of Fit File Forge)

4 Likes
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Sounds interesting, thanks for sharing with the intervals.icu community.

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Anyone that’s checked this out have some feedback?

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Found today, looks great. I will try @swim next Saturday.

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I’ve been making some small tweaks to improve the application. The Coach should be easier to use now and also less laggy.

Question for folks… would you want me to add a feature that allows the Coach to read your training history from Garmin and incorporate that into suggested workouts? I could certainly do that, but it’s perhaps nice that FFF has a unique place in your toolkit, and other apps like Intervals and TrainingPeaks are there for you to understand your workout history. Let me know what you think. If there’s enough interest I can build a Beta feature and see where it goes from there.

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Nice one, I will try this out, as I find creating workouts such a pain!