Create a triathlon training plan with Claude

A training plan from the internet does not know you. It does not know that you never have time on Thursdays, that your sleep has been poor for two weeks and that the last bike ride ran an hour longer than planned. Claude can know all of that — if it can see your data.

Tri-Train offers two ways that complement each other: the plan generator in the app and a conversation with Claude through the MCP server. This guide explains both and shows when each one fits.

Way 1: the generator computes the whole build

The training planner in Tri-Train is deliberately not a language model. From your goal race, profile and current fitness it computes a complete week-by-week progression to race day: base, build, peak and taper, a target load per week, and in every week concrete sessions with steps and targets.

What sets it apart from a template are the rules it guarantees:

• Fitness may only grow by 3 to 8 points per week depending on your level. More hours in your profile do not lift that limit.
• Every few weeks there is a recovery week, and before the race a taper whose length depends on race priority.
• The race distance sets the volume cap and the longest session. A sprint plan does not ramp to eighteen hours a week just because that much time is in your profile.

A language model cannot keep any of these promises: it does not compute deterministically and does not produce the same plan twice for the same input. For the big arc over twelve or twenty weeks, the generator is therefore the right way.

Way 2: Claude plans the week

Where Claude is strong is the concrete. Next week, under your conditions, with your numbers. That needs the connection through the MCP server — how to set it up is in Analyse Garmin data with Claude. Important: to plan, you need the second permission that allows writing.

After that, Claude sees everything that matters for planning:

• your recent weeks with load, sports and form (CTL, ATL, TSB)
• your thresholds, level, weekly hours and training days
• sleep, HRV and resting heart rate from Garmin
• what is already in your calendar

A good brief says what is fixed and what Claude should decide. For example:

> "Plan next week with four sessions. Saturday is the long bike day, Thursday is off. I am five weeks out from the Olympic-distance race, so build phase. Keep the total load about ten percent above last week."

Claude creates the sessions with duration, intensity and steps. You see them in your calendar immediately and can adjust: "Make Tuesday's intervals shorter, I had three bad nights." Claude sees those nights itself and can judge whether the request is justified.

Both ways together

The generator provides the skeleton, Claude adapts it to the week. In practice it looks like this:

1. Add the race, fill in your profile, generate the plan. The build is in place.
2. On Sunday evening, go through the coming week with Claude. Claude sees the plan and the week before and suggests what to move.
3. After every session the activity comes back automatically from Garmin and is matched to the planned session. So Claude sees not only the plan but also what became of it.

That way the plan stays a plan and not a wish list from January.

Onto the watch

Planned sessions go to Garmin as structured workouts: warm-up, intervals with target zones, cool-down — for swimming in pool lengths rather than metres, because that is how the watch counts in the pool. You tell Claude "push this week's sessions to the watch", and in the morning the session is on your wrist.

Undo

Everything Claude writes is journalled. If a brief was misunderstood — wrong week, wrong day, wrong sport — you say "undo that" and the previous state is back. That is why letting Claude plan is not a risk: the way back is always one sentence long.

What Claude does not replace

Claude knows your numbers. It does not know your knee, your work week or how you felt getting off the bike yesterday — unless you tell it. The more context in the brief, the better the week. And whether a plan was good shows not in the calendar but on race day.