The Coach GPT App blends data-driven precision with evidence-based training principles. It integrates objective load metrics (TSS, CTL, ATL, HRV, VO₂max) with subjective markers (RPE, mood, recovery) to generate personalized training analysis.
It uses advanced frameworks like ACWR, Strain, Monotony, Durability Index, and Polarisation Index to deliver clear weekly, seasonal, and wellness reports, ensuring balance between hard and easy days.
This coach blends data-driven precision with evidence-based endurance frameworks, delivering actionable insights across cycling, running, triathlon, and multisport.
By combining objective metrics — TSS, CTL, ATL, HRV, VO₂max, ACWR, Monotony, Strain, Durability, and Polarisation — with subjective feedback such as RPE, mood, fatigue, and recovery, the coach ensures a precise balance between load, readiness, and adaptation.
Grounded in validated research and long-term performance modeling, this approach follows:
The coach continuously monitors ACWR, Polarisation Index, and Recovery Index to detect maladaptation early and adapt training proactively.
Whether targeting an Ironman, Gran Fondo, or Marathon, this system ensures the athlete peaks on time, achieves maximal aerobic fitness, and avoids non-functional overreaching.
The Coach GPT App is fully dependent on Intervals.icu for data. Training activities, wellness logs, and advanced load calculations are sourced directly from Intervals.icu.
For the best results, athletes should ensure their wellness markers (HRV, resting HR, sleep, mood, stress, soreness)
are synchronized to Intervals.icu. This ensures the app can combine objective training load with subjective recovery data for accurate reporting.
Also adding custom fields helps coaching accuracy; Garmin users can expose Vo2maxGarmin and PerformanceIndicators, also IF (Intensity Factor) is a useful metric.
Special thanks to David Tinker, the creator of Intervals.icu, for building and maintaining the platform that makes this integration possible.
Anonymised examples for a cycling-focused athlete.
📊 Weekly Report — Unified Reporting Framework v5.1
Athlete [Anon] Discipline Cycling Window 2025-10-20 → 2025-10-26 Audit ✅ Final 🔹 Key Stats
Volume 10 h 46 m Load (TSS) 579 CTL / ATL 92 / 81 Form +11 ACWR 1.01 Monotony 3.6 ⚠ Strain 579 🔸 Training Quality
Z1–Z2 Distribution 70 % ✅ Z3–Z5 Time 30 % ⚠ FatOx Index 0.80 ✅ HR–Power Decoupling 4.9 % ✅ 🔹 Efficiency & Adaptation
Benchmark Index Stable (+0.4 %) Specificity Index 0.74 → 0.77 Durability Marker High 🔸 Recovery & Wellness
HRV 46 ms RestHR 44 bpm Sleep 7.6 h avg Fatigue / Stress / Soreness Low 📈 Performance Insights (Automated)
📆 Season Report — Unified Reporting Framework v5.1
Athlete [Anon] Window 2025-09-15 → 2025-10-26 Phases Build → Overload → Deload Audit ✅ Final 🔹 Key Stats
Total Volume 61.3 h Total Load (TSS) 3330 Average ACWR 1.08 CTL Trend +12 ↑ Recovery Index 0.63 Monotony 2.8 ✅ Strain 930 ✅ 🔸 Training Quality
Polarisation Index 0.74 ✅ FatOx Index (Avg) 0.81 ✅ Endurance Durability High 🔹 Efficiency & Adaptation
Benchmark Index +2.1 % Specificity Index 0.75 → 0.79 Durability Marker Improved 🧱 Phase Summary
Phase Span Volume (h) Load (TSS) Trend Build 2 wks 18.4 940 ↑ Overload 3 wks 31.7 1770 ↑↑ Deload 1 wk 11.2 620 ↓ 🔸 Recovery & Wellness
HRV Trend -6 % during Overload ⚠ RestHR Stable (44 bpm) Sleep Average 7.4 h Stress / Fatigue Normalised after Deload 📈 Performance Insights
💠 Wellness Trend — Unified Reporting Framework v5.1
Athlete [Anon] Window 2025-10-13 → 2025-10-26 Audit ✅ Final 🔹 Key Stats
HRV Avg 46 ms RestHR 44 bpm Sleep Duration 7.6 h Sleep Quality 84 % Stress / Fatigue / Soreness Low (2 / 5) Mood Good ↑ 🔸 Recovery Summary
Recovery Index 0.68 ✅ Readiness Score 0.72 ✅ Hydration Adequate (~2.3 L/day) Sleep Consistency High 📈 Performance Insights
🧩 Executive Summary — Unified Reporting Framework v5.1
Athlete [Anon] Scope Load & Recovery Overview Period Last 42 days Audit ✅ Final 🔹 Key Stats
Volume 61.3 h Load (TSS) 3330 CTL / ATL 90 / 84 Form +6 ACWR 1.08 ✅ Monotony 2.8 ✅ Strain 930 ✅ Polarisation 0.74 ✅ 🔸 Recovery & Wellness
HRV 46 ms ✅ RestHR 44 bpm ✅ Recovery Index 0.68 ✅ Readiness 0.72 ✅ 📈 Performance Insights
In the GPT Store, search for: "Intervals icu training coach"
For integration, customization, or coaching inquiries, connect via GitHub or Intervals.icu
github.com/revo2wheels