🤖 AI Running Coach · Free
The AI Running Coach
That Actually Adapts
WattRun is the AI running coach that tracks your fitness automatically, generates personalized training plans and gives you data-driven feedback after every run.
TL;DR — Why WattRun
- AI-generated plans that adapt when life happens — unlike static PDFs
- CTL, ATL, TSB automatically calculated from every run
- 17 automated coaching triggers catch overreaching, PRs, pacing issues
- Strava integration — connect once, never upload manually
- Powered by Claude AI — cutting-edge language model for analysis
- Free to try — no credit card required
Why Static Training Plans Fail
You downloaded a 16-week marathon plan. Week 3: work gets busy, you miss two runs. Week 5: you catch a cold. Week 8: the long run feels too hard. The plan doesn't care. It ploughs ahead, oblivious to your actual state.
This is how 99% of runners fail their goals — not because they lack motivation, but because they're following a plan that ignores reality.
An AI running coach analyzes your actual training data and adapts the plan dynamically. It knows your real fitness (CTL), it sees when you're overreaching (rising ATL), and it reschedules sessions when you need recovery.
What WattRun Does Differently
🧠
AI-generated plans
Powered by Claude AI. Tell it your goal, your fitness, your schedule — get a personalized plan in seconds.
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CTL/ATL/TSB tracking
Chronic and acute training load calculated automatically after every run. See your real fitness progression.
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17 coaching triggers
Automatic insights: overreaching warnings, PR detection, pacing analysis, recovery nudges — without manual review.
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Strava auto-sync
Connect once. Every run flows in automatically. No more manual FIT uploads.
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Goal tracking
Set a target race and date. WattRun builds your taper, predicts your finish time and alerts you if you're off-track.
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Pace zones done right
5 training zones calculated from your actual data. Zone 2 base, threshold, VO2max — all in one place.
The Metrics That Matter
CTL (Chronic Training Load) measures fitness over 42 days. Rising CTL = getting fitter. WattRun recommends +5 CTL/week as the safe upper limit.
ATL (Acute Training Load) measures fatigue over 7 days. Spikes are normal after hard sessions; WattRun warns when ATL stays elevated for too long.
TSB (Training Stress Balance) = CTL − ATL. Positive TSB = fresh and ready. On race day, aim for +5 to +15.
| Metric | What it means | Window | Target |
|---|
| CTL | Fitness | 42 days | Build slowly (+5/week max) |
| ATL | Fatigue | 7 days | Peaks OK, should recover fast |
| TSB | Form = CTL − ATL | Daily | Race day: +5 to +15 |
| TSS | Single session load | Per run | 400–600/week (marathon prep) |
How It Works — In 60 Seconds
- Connect Strava (or upload FIT files from Garmin, Wahoo, COROS)
- Set your goal — target race, finish time, training days per week
- AI generates your plan based on your actual CTL and schedule
- Run and track — every activity syncs automatically
- Get insights — 17 triggers analyze every run for issues and wins
- Plan adapts — miss a session? CTL drops? The plan reschedules
🚀 Start with WattRun — Free
No credit card. No subscription traps. Connect Strava, set a goal, get your AI-generated training plan in under 2 minutes.
Start for free →
Free · No subscription · Start instantly
Frequently Asked Questions
What is an AI running coach?+
An AI running coach analyzes your training data automatically and provides personalized feedback, training plans and insights after every run. Unlike static PDF plans, AI coaches adapt to your actual fitness, schedule and performance.
How does WattRun use AI for running training?+
WattRun uses Claude AI to analyze your runs and generate personalized coaching insights. After every activity, 17 automated triggers check for pacing issues, personal records, overreaching signals and more. The AI then generates or adjusts your training plan based on what it sees.
What is CTL in running training?+
CTL (Chronic Training Load) measures your fitness over 42 days. A higher CTL means better fitness. WattRun calculates your CTL automatically after every run from your Strava or FIT file data. Most runners aim to build CTL by 5 points per week max to avoid injury.
Can AI create a marathon training plan?+
Yes. WattRun's AI generates personalized marathon and half marathon training plans based on your current CTL, goal time and available training days. The plan adapts dynamically when you miss sessions or your fitness changes — something static PDF plans cannot do.
Is WattRun free?+
Yes, WattRun is free to use. Connect your Strava account or upload FIT files from Garmin/Wahoo/COROS and get AI coaching insights immediately — no credit card required.
Does WattRun work for both cycling and running?+
Yes. WattRun started as a cycling training tool and now supports running too. All the CTL/ATL/TSB math works identically for both sports. You can track rides, runs, or both in the same account.
