RunSync: Structured Running Workout Builder with Garmin Sync and AI Input

Garmin Connect can build complex structured workouts, but runners who create several sessions a week can spend a surprising amount of time entering steps, repeat blocks and pace targets.

RunSync was built by Graham, a self-coached recreational runner who moved from Garmin Coach to using ChatGPT as a training tool, then found no clean way to get the AI-generated sessions onto his watch. He wrote a command-line tool to push workouts to Garmin via the API, then turned it into a full web app. RunSync is that app.

How it works

TL;DR: Describe a workout in plain English, or build it step by step. RunSync converts it into a structured Garmin workout and sends it directly to Garmin Connect.

RunSync connects through Garmin’s official authorization flow. Users sign in with Garmin directly; RunSync does not ask for or store their Garmin password.

Once connected, workouts can be sent from RunSync to the user’s Garmin Connect account, from where supported Garmin devices receive them through the normal Garmin sync process.

The builder supports warm-ups, running steps, repeat blocks, recoveries, tempo sections and cool-downs.

RunSync also includes training pace tools based around VDOT, a race-performance-based fitness score developed by Jack Daniels to derive appropriate training paces from recent race performances. For a runner with a VDOT of 51, RunSync currently calculates:

• Easy / Long: 4:49 to 5:47 per km
• Marathon: 4:21 to 4:46 per km
• Threshold: 4:02 to 4:11 per km
• Interval: 3:47 to 3:56 per km
• Repetition: 3:30 to 3:38 per km

Saved training paces can then be applied to compatible workout sections, so a threshold or easy target reflects the runner’s current pace bands rather than having to be entered from scratch each time.

The AI input layer uses the OpenAI API. A runner might type:

“15 minutes easy, then 3 x 6 minutes at threshold with 3 minutes easy jog recovery, then 10 minutes easy.”

RunSync converts the description into an editable structured workout with the appropriate workout sections and durations. Saved training paces can then be applied to those sections before the workout is sent to Garmin.

Nothing is sent blindly. The generated workout is presented for review, individual steps can be changed, and the runner can either send it immediately or schedule it for a specific date.

Scheduling is handled through RunSync’s training calendar. A runner can build a full week of sessions (intervals on Tuesday, threshold on Thursday, long run on Sunday), schedule each to the correct date and use automatic Garmin delivery so the workouts are available when required.

Save it once, reuse it

Not every workout needs to start with AI or from an empty builder. RunSync includes a library of pre-built workout templates for common structured sessions, giving runners a starting point that can be adapted to their own training.

Workouts created in RunSync can also be saved and reused. A runner who regularly performs the same threshold, interval or long-run session can build it once, save it to their workout library, then reopen, edit, schedule or send it to Garmin again when it comes back around in the training plan.

That is particularly useful for self-coached runners whose training tends to repeat familiar structures. A 3 x 6-minute threshold workout might become 3 x 8 minutes a few weeks later, for example, without recreating the warm-up, recovery structure and cool-down from scratch.

Starter templates are available on the Free tier, with the larger running template library available with RunSync Run and RunSync Complete.

A worked example: VDOT 51, 3 x 6 minutes at threshold

Consider a self-coached runner with a VDOT of 51 who wants to run three six-minute threshold repetitions with easy recoveries.

In Garmin Connect, the runner needs to create the warm-up, build a threshold and recovery pair, configure the repeat block, enter the pace targets and add the cool-down.

In RunSync, the runner can instead type:

“10 min easy warm-up, 3 x 6 min at threshold with 3 min easy recovery, 10 min easy cool-down.”

RunSync converts the description into the components of a structured workout that Garmin understands, while tying the pace targets back to that runner’s saved training paces.

The runner can review the workout, make any changes, then either send it to Garmin immediately or put it on the RunSync calendar for a particular day.

Once delivered through Garmin Connect, the workout is available on a compatible Garmin device as a structured session, allowing the watch to guide the runner through the workout rather than requiring them to remember each change manually.

Where it sits relative to the tools already covered here

RunSync approaches the same problem from a broader angle, combining structured running workouts, reusable saved workouts and templates, natural-language generation, saved training paces, calendar scheduling and strength training in one web app.

Type to Run generates on-demand pace-based workouts via a Connect IQ app. It has no training calendar and no push to Garmin’s scheduled workout list. Sessions are generated on the watch at the time of running rather than being pre-built and scheduled in advance.

Pacier converts a photograph of a training plan into a structured Garmin workout using AI vision. It solves the manual transcription problem for runners following book-based plans. It covers running rather than strength integration.

Workout Writer takes plain-text descriptions and converts them to structured workouts for Apple Watch and Garmin. It is focused on creating individual sessions rather than combining the workout builder with RunSync’s wider training calendar and strength features.

LiftTrack approaches the problem from the strength side, with custom exercises, AI-built strength sessions, progressive overload and Garmin sync.

RunSync combines structured running workouts, AI-assisted generation, VDOT-based training paces, calendar scheduling, automatic Garmin delivery and strength training under one subscription.

Strength workouts

RunSync Complete includes the Strength Builder with direct Garmin sync.

Users can create sessions using sets, weights and rest periods, select exercises supported by Garmin, and send the resulting structured strength workout through Garmin Connect.

This gives runners who also strength train a way to manage both sides of their training within the same RunSync account rather than using one product for their structured running and another for gym sessions.

Strength workouts can also be incorporated into the training calendar alongside running sessions.

Pricing and compatibility

RunSync is a web app and runs in a browser, so there is no separate desktop application to install.

The annual prices mean RunSync Run works out at £1/month and RunSync Complete at £2/month when paid annually.

RunSync sends structured workouts through Garmin Connect using Garmin’s official Training API. Garmin device support depends on whether the individual device supports the workout type, targets and structured workout features being used. Runners with older or less common devices should check Garmin’s compatibility information for their particular model.

RunSync is built by an independent developer and is enrolled in the Garmin Developer Program. It is not affiliated with or endorsed by Garmin.

Summary

RunSync is aimed at self-coached Garmin runners who already know the training they want to do but want a faster route from idea to structured workout.

It combines a manual workout builder, reusable saved workouts and pre-built templates, natural-language AI input, reusable training paces, calendar scheduling and Garmin sync, with strength training included in RunSync Complete.

Free users can test the basic workflow. RunSync Run costs £1.49 month-to-month or £12/year, equivalent to £1 per month when billed annually. RunSync Complete costs £2.49 month-to-month or £24/year, equivalent to £2 per month annually.

More at RunSync.

Quick answers

Does RunSync work with all Garmin watches?
Not necessarily. RunSync delivers workouts through Garmin Connect, but Garmin device support varies according to the device, sport and structured workout features being used. If a Garmin device supports the relevant structured workout through Garmin Connect, RunSync can deliver that workout through the same Garmin ecosystem. Users with older devices should check compatibility for their individual model.

Does the AI feature require a specific subscription?
AI natural-language workout generation is available on RunSync Run and RunSync Complete. Run includes 8 AI generations per month and Complete includes 20. The Free tier provides the manual Run Builder and limited Garmin syncs so runners can try the core workflow before upgrading.

Is Strength Builder a separate product or part of RunSync?
Strength Builder is part of RunSync and is included with RunSync Complete. There is no separate account or subscription. Running and strength workouts can both be managed through RunSync and incorporated into the same training calendar.

Does RunSync store my Garmin password?
No. RunSync uses Garmin’s official authorization flow. Users sign in via Garmin’s own login page, and RunSync never sees the password.

Related reading on the5krunner

• BulkForged: A Lifting Coach That Shows Its Working: closest sibling, another indie developer building structured workout tools that sync to Garmin, focused on the strength side.
• Vertical AI Coach: Build Your Training Partner: another indie AI training tool built on the show-your-working principle, citing peer-reviewed research behind every coaching call.
• Beatpace: Garmin Running Music That Plays Your Workout Structure: another indie Garmin Connect IQ app on the running side of the platform, matching music tempo to structured workout phases.

Author: Graham Whitehead, developer of RunSync, edited by the5krunner.

If you enjoyed reading this, here is another in the Indie Spotlight series: BulkForged: A Lifting Coach That Shows Its Working.

Last Updated on 12 October 2026 by tfk the5krunner