How does an AI running coach actually work?

A connector, not a separate app

Unlike a classic coaching app, an AI coach doesn't live in a dedicated screen: it lives in the conversation you already have with your AI assistant. The MCP (Model Context Protocol) connector gives that assistant tools it can call mid-conversation — read your profile, build a session, place it on your calendar.

In practice, adding Running Workout to Claude, ChatGPT or Gemini is enough: the coach's instructions (when to ask what, how to build a week) are carried by the connector itself, not by an extra file or setting to install.

What the coach reads before proposing a session

Before building anything, the coach reads a profile computed automatically from your Garmin Connect activities:

• — Your VMA and its origin — measured by a test, declared, or still unknown.
• — Volume run over the last 30 days and your longest run over 90 days.
• — Your training load (ACWR), to catch a ramp-up that's too fast.
• — Your maximum and resting heart rate.
• — Sessions already scheduled on your Garmin calendar, so it never proposes two on the same day.

This reading is what sets an AI coach connected to your data apart from a plain generic session generator.

The coach never invents a VMA

A session set in percent of VMA only makes sense if that VMA is known and reliable. Running Workout accepts only three origins for it: a verified test, a time reported by the athlete, or a proposal the athlete has explicitly accepted.

This rule applies to every session built, week after week — not just the first conversation.

From conversation to watch

Once a session is decided, the coach calls the write tool, which places it directly on the Garmin Connect calendar on the chosen date, with typed targets the watch can execute (pace, % VMA, heart rate, power depending on the sport).

The following week, the coach reads back completed sessions, compares them to plan, and adjusts what's next — the loop restarts with every exchange, so no plan stays frozen in a forgotten conversation.

Three quality families, one reference: your VMA

All of Running Workout's running intensity is calculated from a single number: your VMA, maximal aerobic speed. Once known, it defines three families of quality sessions:

• — VMA work, in short repeats, to push back the aerobic ceiling.
• — Threshold work, in longer blocks, to hold sustained intensity longer.
• — Race-specific pace, set to the goal (5K, 10K, half or marathon), to get the body used to race-day rhythm.

The long run in easy endurance rounds out these three families, usually paced by heart rate rather than pace so it doesn't drift too fast.

Five plans, one engine

The coach relies on five plans built on the same engine, from a no-VMA restart up to the marathon: restart (6 weeks), 5K (6 weeks), 10K (8 weeks), half marathon (10 weeks) and marathon (12 weeks), each available in several variants of 3 to 7 sessions a week.

The structured running sessions page details the four target types Garmin accepts — pace, % VMA, % max heart rate and cadence — and what each brings depending on the session.

What triggers an adjustment

The coach doesn't just run through a frozen plan. Several signals, read from your Garmin data, can make it adjust what's next:

• — A missed session, or one completed well below target.
• — A training load (ACWR) climbing too fast from one week to the next.
• — A newly measured VMA, which automatically recalculates every upcoming target.
• — A schedule constraint mentioned in the conversation (travel, minor injury, an upcoming race).
• — A changed race goal — new date, new distance.

Frequently asked questions