Simma turns swimming, running and cycling data into coaching for triathletes and endurance athletes. It reads activities from Garmin, computes the numbers a triathlon coach actually uses — form calibrated to each athlete's own history, per-sport training status across swim, bike and run, pace and stroke detail down to the lap — and gives ChatGPT the finished picture rather than raw files.
For coaches. Whether you coach triathletes, runners, cyclists or swimmers, ask who on your roster needs attention this week and why. Open one athlete and get three weeks of sessions bucketed by week, their load against their own baseline, race goals with days to go, the linked training plan, and pre-computed flags for the things worth a message. Draft that message in your own voice, save it, and send it from Simma so replies thread back into the same conversation. Keep private notes per athlete that steer every future draft. Every number is computed by Simma; ChatGPT writes the words.
For athletes. Ask how your triathlon training is going and get an honest read against your own history, not a generic scale. Look up any swim, ride or run in detail, find the sessions where you faded or negative-split, set and track race goals, link a training plan, and message your coach — or, if you are self-coached, get the same analysis Simma gives a coach.
What it does not do. Simma never sends anything on your behalf without an explicit confirmation step, and read tools are marked read-only so ChatGPT can use them freely. Tools that overwrite a setting, delete a goal or end a coaching relationship are marked destructive so ChatGPT asks before running them. Sending a message is gated twice: the draft is shown to you in full and must be approved before it goes.
You need a Simma account; new users can create one during sign-in. Activity data comes from Garmin Connect, linked from the Simma web app. Your training history loads within a few minutes of linking, as long as historical data is allowed on Garmin's consent page.