Guide
Cycling Training with ChatGPT and Claude — A Working Workflow
AI as a second brain for a cyclist: writes a plan in watts matching your fitness, reviews a ride after the workout, adjusts the week after missed sessions. All through Intervals.icu data: FTP, zones, history, wellness. STAS is the bridge that feeds those numbers to ChatGPT and Claude.
Why AI for a Cyclist
Cycling is the most data-driven endurance sport. Power meters produce a number every second, FTP shifts over weeks, power curve reveals strong and weak zones. That's exactly the kind of data LLMs work well with.
AI sees your FTP and builds the session as 4×10 @ 91% FTP, not "endurance with 2 surges". Numbers flow to Garmin / Wahoo through Intervals.icu with one click.
After the ride AI reads Intervals.icu: average power, NP, VI, drift, time-in-zone. Tells you what worked, where you missed target, what it means for the plan.
Missed intervals because of rain or a flight? AI reshuffles remaining days accounting for accumulated load, not a textbook template.
How It Works
The Pipeline: Head Unit → Intervals.icu → AI → Back
Neither ChatGPT nor Claude connects to your head unit directly. The data path looks like this:
1. Head unit / watch
Garmin, Wahoo, Karoo, Zwift, TrainerRoad. They write a FIT file with power, HR, cadence, GPS.
2. Intervals.icu
Receives the FIT, computes TSS, IF, NP, updates CTL/ATL, recalculates power curve. This is the single store for all your cycling history.
3. STAS
A bridge between Intervals.icu and AI: a Custom GPT for ChatGPT, an MCP connector for Claude. Grants the LLM access to numbers, profile, zones, and goals.
4. ChatGPT or Claude
Works as a virtual coach: reviews workouts, builds the next week's plan, answers "why was NP 10% above average" in plain language.
Step 1
First — FTP and Zones in Intervals.icu
AI without numbers works worse: without FTP it can't prescribe wattage targets, without zones it can't interpret past rides. So step one is Intervals.icu, not AI.
1. Test FTP (20-minute test × 0.95 or Auto FTP from history). 2. Check Coggan zones. 3. Verify that the last 4-6 weeks of rides are pulled in from Garmin / Wahoo. Without that history the AI plan will be built on a template, not on you.
Step 2
Connecting a Custom GPT or Claude
STAS exposes Intervals.icu data to two kinds of AI:
ChatGPT (Custom GPT)
Log in once through Intervals.icu OAuth. Open the "STAS Running/Cycling Coach" GPT — it already sees your history and can review a workout immediately.
Claude (via MCP)
In Claude Desktop / Web, connect the STAS MCP server. Claude gets access to the same data. Bonus — Claude can hold the full week or month in context and see the whole cycle at once.
Typical Scenarios
"Review my last ride"
AI reads Intervals.icu: structure, NP, TSS, drift, % in zone. Says: "The 2×20 hit the plan, but on the second interval pulse drift +8 bpm — possibly fueling or heat. NP / avg = 1.03 — almost flat, good pacing". No generic lines.
"Write a plan for a race in 8 weeks"
AI looks at current CTL, FTP, race type (crit / gravel / L'Étape), your registered days. Produces 7 concrete sessions in watts, with push to the Intervals.icu calendar → to Garmin / Wahoo.
"Missed 3 days — what about the plan?"
AI checks TSB (freshness), accumulated stress, days left to goal. Reshuffles remaining sessions: which to cut, which to keep, where to move intensity. Not abstract "rest" — concrete numbers for remaining days.
"Why am I not growing FTP?"
AI looks at 3-month power curve, time-in-zone distribution, TSB trend. Can say: "Last 6 weeks 80% in Z2-Z3 and only 2 VO2 sessions — classic plateau. Two months with 2 VO2 and 1 SST per week will move the curve". With numbers from your own history.
Where AI Falls Short
An honest list — so there are no illusions.
AI isn't in your pocket during the race — it won't say "attack now". That's still a coach's job or your own tactical sense.
If your knee hurts, AI doesn't replace a bike-fit. It can suggest hypotheses (cadence, q-factor), but treatment is a specialist's job.
Pro / cat-1 needs a coach who knows you personally. For amateurs (gran fondo, granfondo, brevet, Ironman AG) AI through Intervals.icu covers 90% of needs.
FAQ
Do I need Intervals.icu or AI subscriptions?
Intervals.icu is free for all core features (FTP, zones, CTL, Garmin push). ChatGPT Plus is required for Custom GPT. Claude Pro for MCP connector. STAS is a free bridge. Total: $20/mo for AI + free Intervals.icu.
ChatGPT or Claude — which is better for cycling?
Claude holds long context (whole week or month of the plan at once) — nicer for cyclical planning. ChatGPT is faster for quick "review one ride". On core tasks, both are fine.
Is it possible without a power meter?
Yes — AI will work with HR and pace. But plan quality drops significantly: without watts there's no precise target for intervals and no TSS. For serious prep a power meter changes a lot.
Will AI replace a real coach?
For amateurs with standard goals (first century, first gran fondo, Ironman AG) — yes, 90% of the time. For pro / elite — it's an assistant, not a replacement.
Does it work for gravel / MTB?
Yes. Power and TSS in Intervals.icu don't depend on surface, unlike running pace. A 4×10 SST works identically on pavement and gravel.
Where does AI get it wrong most often?
On interpreting feelings without data. If there's no wellness entry or HRV, AI only works with objective numbers. For fine plan tuning, 30 seconds a day on Intervals.icu wellness (sleep, fatigue, motivation) is worth it.
Related
A Cycling Coach in ChatGPT or Claude — via Intervals.icu
STAS connects your Intervals.icu to ChatGPT and Claude. You get an AI coach working with your watts, CTL, and history — not generic advice.
Connect Intervals.icuFree — no subscription