How to Use TrainingPeaks for Triathlon Training

What Is TrainingPeaks?

TrainingPeaks is the most widely used training management platform in endurance sport, used by professional triathletes, Olympic coaches and hundreds of thousands of age-groupers worldwide. It allows you to plan workouts, upload training data from your GPS watch, and analyse key fitness metrics to understand whether your training is actually making you better. If you’re training with a plan or working with a coach, TrainingPeaks is usually the platform where everything is organised.

The Three Key Metrics You Need to Understand

TrainingPeaks uses a performance management system built around three numbers derived from your training data. Understanding these three metrics is the foundation of using the platform effectively.

CTL (Chronic Training Load) — your fitness: A rolling 42-day weighted average of your training stress. Think of it as your long-term fitness level. The higher your CTL, the more training your body has absorbed over the past six weeks.
ATL (Acute Training Load) — your fatigue: A rolling 7-day weighted average. When ATL spikes above CTL, you’re building fatigue faster than your body can recover. This is normal during hard training blocks, but sustained high ATL leads to overtraining.
TSB (Training Stress Balance) — your form: TSB = CTL − ATL. A positive TSB (above zero) means you’re fresher than you’ve been recently. Elite athletes often target a TSB of +5 to +20 on race day by tapering CTL down and bringing ATL lower.

Setting Up TrainingPeaks for Triathlon

Getting started takes around 20 minutes. Here’s the process step by step.

Step 1 — Create an account: The free version gives you a 7-day training calendar, basic workout uploads, and one week of history. The Premium tier (around £12/month) adds full calendar access, the performance management chart, and analytics. Most athletes who use it seriously upgrade to Premium.
Step 2 — Connect your devices: Sync your Garmin, COROS, Wahoo, or Polar account via Settings → Connected Apps. Once connected, all future workouts upload automatically.
Step 3 — Set your thresholds: Under Athlete Settings, enter your current FTP (for cycling), threshold pace (for running), and threshold pace per 100m (for swimming). These calibrate how Training Stress Score (TSS) is calculated for each sport.
Step 4 — Apply a training plan: TrainingPeaks has a library of paid plans from coaches and publishers, or your coach can push a custom plan directly to your calendar. Plans automatically populate with workouts on the right days.

Reading the Performance Management Chart

The Performance Management Chart (PMC) is the most important view in TrainingPeaks. It shows CTL (blue line), ATL (pink line), and TSB (yellow bars) over time. A well-structured season typically looks like a series of training blocks where ATL climbs above CTL (building fatigue), followed by brief recovery periods where TSB recovers, then repeats at a slightly higher CTL baseline each cycle.

For race-day targeting, aim for your CTL to peak 2–3 weeks before your A-race, then taper to bring TSB into positive territory. Many triathletes target a CTL of 80–120 for a 70.3 and 100–150+ for a full Ironman, though individual responses vary significantly.

Practical Tips for Getting the Most from TrainingPeaks

Log every workout, even easy ones. TSS is cumulative — missing uploads skews your CTL and makes the PMC unreliable.
Use the planned vs. actual comparison to identify patterns: are you consistently underperforming on certain workout types?
Don’t obsess over daily TSB swings. The trend over weeks matters far more than the number on any given day.
Set weekly TSS targets for each discipline and use them as a guide when life disrupts your schedule — it helps you prioritise which sessions to keep.
Free Strava users can sync to TrainingPeaks for basic upload, making the Premium upgrade more accessible if you already run Strava.