Training Diary: A Complete Guide to TrainingPeaks and Intervals.icu

Introduction

Training without records is training without evidence. Concepts like the Banister model, PMC, CTL/ATL/TSB remain mere ideas without tools to carry them. TrainingPeaks and Intervals.icu are the two most important training analysis platforms of our time—the former is the commercial standard, the latter the free alternative. For Taiwanese cyclists, choosing the right tool can double training efficiency.

TrainingPeaks vs. Intervals.icu Comparison

TrainingPeaks: The industry standard, used by world-class coaches; complete PMC, WKO5 advanced analytics (NP/IF/TSS designed by Coggan himself), training plan marketplace, mature coach collaboration; downsides are the Premium subscription at USD 19.95/month and a dated interface.

Intervals.icu: Completely free (accepts donations), PMC comparable to TP, modern interface, automatically syncs with Strava and Garmin Connect, supports HRV, weight, and sleep integration; downsides are the lack of a ready-made workout marketplace and weaker coach collaboration.

Core Metrics Comparison

Core Fields of a Training Log

Every training session should record: time/distance/elevation gain, average power/heart rate, TSS/IF/NP, subjective fatigue RPE 1–10, weather (temperature/humidity/wind speed), workout type (Z2, SST, HIIT, Race), and post-session notes (feelings, issues, adjustments).

Advanced Metric Applications

• PMC: CTL rises steadily, TSB rises to +5~+15 in the 14 days before a race
• PDC: 5-second/1-minute/5-minute/20-minute/60-minute power, identify strengths and weaknesses
• eFTP / Time in Zone: Automatically estimates eFTP, review intensity distribution monthly

Research Background

Banister’s 1975 Fitness-Fatigue model laid the mathematical foundation; Coggan commercialized it into the TSS/IF/NP system in 2003; Sanders et al. provide a comprehensive review of quantifying training load.

Practical Recommendations

• Amateur cyclists: Intervals.icu is more than sufficient, saves money
• Those needing coach collaboration: TrainingPeaks is more mature
• Record RPE and sleep hours daily—more valuable than TSS
• Don’t be enslaved by numbers: subjective fatigue takes priority over TSS data
• Combining HRV tools provides full recovery coverage

Conclusion

A training log is not just for looking at—it is a tool that lets your future self converse with your past self. Reviewing records six months or a year later reveals your progress patterns, injury patterns, and burnout patterns—insights no book can give you. For Taiwanese cyclists, Intervals.icu is free and fully featured, making it the most cost-effective entry point. Start today: spend 5 minutes logging after each session, and six months from now you will thank yourself.

Related Reading

• In-depth Review of Cycling Training Apps: TrainingPeaks vs intervals.icu vs Today’s Plan Feature Comparison
• How to Keep a Cycling Training Log: Strava vs Garmin vs TrainingPeaks
• The Complete Guide to Self-Coaching with TrainingPeaks: From Data Novice to Training Planner
• Training Peaks Fully Explained: TSS, ATL, CTL and Race Preparation Adjustments