The latest articles on DEV Community by Ardy Mickle (@doublethreshold). https://dev.to/doublethreshold https://media2.dev.to/dynamic/image/width=90,height=90,fit=cover,gravity=auto,format=auto/https:%2F%2Fdev-to-uploads.s3.us-east-2.amazonaws.com%2Fuploads%2Fuser%2Fprofile_image%2F4123431%2F963d1226-e9ed-484b-b37b-1792d4675c7a.jpeg https://dev.to/doublethreshold en Ardy Mickle Sun, 13 Sep 2026 17:46:45 +0000 https://dev.to/doublethreshold/i-built-a-self-hosted-ai-running-coach-that-reads-my-garmin-and-plans-my-runs-and-lifts-3hg https://dev.to/doublethreshold/i-built-a-self-hosted-ai-running-coach-that-reads-my-garmin-and-plans-my-runs-and-lifts-3hg <p>For a long time my "coach" was me uploading screenshots of Garmin Connect into Claude and asking what to do next. Earlier this year I set up a self-hosted agent on a Mac mini instead, and gave it read access to my Garmin (sleep, HRV, resting HR, VO2 trend, laps) through an MCP, my Strava uploads, and a folder where it keeps notes on me. Then I wrote it a long instruction file describing how I want to be coached. No more screenshots; it reads the data straight from the source.</p> <h2> What it does day to day </h2> <p>It messages me at 8am, checks my Garmin sleep and HRV before asking how I feel, then sets the day.</p> <p><a href="https://media2.dev.to/dynamic/image/width=800%2Cheight=%2Cfit=scale-down%2Cgravity=auto%2Cformat=auto/https%3A%2F%2Fdev-to-uploads.s3.us-east-2.amazonaws.com%2Fuploads%2Farticles%2Ff73293ytvoqrxu0mq401.png" class="article-body-image-wrapper"><img src="https://media2.dev.to/dynamic/image/width=800%2Cheight=%2Cfit=scale-down%2Cgravity=auto%2Cformat=auto/https%3A%2F%2Fdev-to-uploads.s3.us-east-2.amazonaws.com%2Fuploads%2Farticles%2Ff73293ytvoqrxu0mq401.png" alt=" " width="800" height="811"></a></p> <p>It designs the run and writes it to Garmin Connect, so I press start on the watch and go. It polls Strava, so the moment a run uploads it already knows, pulls the laps, and grades the session against what it prescribed, with the numbers.</p> <p><a href="https://media2.dev.to/dynamic/image/width=800%2Cheight=%2Cfit=scale-down%2Cgravity=auto%2Cformat=auto/https%3A%2F%2Fdev-to-uploads.s3.us-east-2.amazonaws.com%2Fuploads%2Farticles%2Ffhogdcj7dqb9vcz60fd0.png" class="article-body-image-wrapper"><img src="https://media2.dev.to/dynamic/image/width=800%2Cheight=%2Cfit=scale-down%2Cgravity=auto%2Cformat=auto/https%3A%2F%2Fdev-to-uploads.s3.us-east-2.amazonaws.com%2Fuploads%2Farticles%2Ffhogdcj7dqb9vcz60fd0.png" alt=" " width="800" height="840"></a></p> <p>It tracks my times, distances and lift numbers over time and decides when the load goes up. It tells me what to eat and when around hard sessions. And it adapts: this week it swapped an all-out 10K time trial for a progressive build after looking at the 14K I'd done the day before and the week's load.</p> <h2> Result </h2> <p>I set a sub-20 5K goal and got there about a month later. Years of training came before that, so the coach didn't make me fast in a month; it made the last stretch a lot less guessy, and it saves me the hour a week I used to spend planning.</p> <h2> Caveats </h2> <p>It's not an app. It's an agent framework (Hermes) plus config. You run it yourself, you need a model API key and a Garmin login. It occasionally reads Garmin's readiness score too literally, so I told it to ignore that metric.</p> <h2> The config is open </h2> <p>The generic skeleton of my setup, with the personal bits stripped out, is here: <a href="https://github.com/upandawaybackdoorscrewball/runcoach" rel="noopener noreferrer">https://github.com/upandawaybackdoorscrewball/runcoach</a></p> <p>Curious what others do with their training data beyond staring at Strava.</p> ai opensource hermes agentskills