TrainingPeaks and CTL-ATL-TSB

TrainingPeaks has been the reference platform for data-driven training planning in cycling for years. Pro teams, ambitious amateurs, and triathletes use the software to quantify training load, make progress visible, and align form precisely with important races. At the center is the Performance Management Chart (PMC): the three metrics CTL, ATL, and TSB represent fitness, fatigue, and form as rolling curves. Those who understand these metrics and combine them with a current FTP as a reference no longer train by gut feeling, but with an objective control tool.

What is TrainingPeaks?

TrainingPeaks is a cloud-based training platform that imports, structures, and analyzes training data from power meters, bike computers, and smart trainers. Athletes plan sessions in the calendar, coaches assign workouts, and after each ride wattage, heart rate, cadence, and duration flow into the analysis. The platform automatically calculates metrics such as Normalized Power (NP), Intensity Factor (IF), Training Stress Score (TSS), and the PMC values CTL, ATL, and TSB.

The strength of TrainingPeaks lies in connecting planning and analysis: a planned interval session with a target TSS can be compared with the actual load ridden. Deviations – too little wattage, pauses too short, total load too high – become immediately visible. For cyclists with a power meter, TrainingPeaks is thus the link between hardware and structured periodization.

Core Features at a Glance

Calendar and workout library – Structured sessions with watt targets, interval patterns, and notes for indoor and outdoor training.
Automatic data import – Synchronization from Garmin, Wahoo, Zwift, TrainerRoad, and other services.
Performance Management Chart (PMC) – Graphical display of CTL, ATL, and TSB over weeks and months.
Coach-athlete connection – Coaches see load, comments, and adjustment needs in real time.
Target races and A-priorities – Season planning focused on main competitions and tapering phases.

Important: Without current FTP values, TSS, CTL, ATL, and TSB lose their meaning. A regular FTP test is a mandatory prerequisite for meaningful PMC analysis.

Understanding the Performance Management Chart (PMC)

The PMC is the heart of load management in TrainingPeaks. It shows three rolling curves calculated from the daily TSS value. Each completed session increases or changes ATL and CTL; rest days lower the curves. The difference between fitness and fatigue yields TSB – an indicator of current form.

PMC progression over 16 weeks:

CTL (blue line): slowly rising over the season build-up
ATL (red line): wave-like with peaks after load weeks
TSB (yellow line): fluctuating, positive peak shortly before marked target race
Markers: season start, load block, and tapering phase highlighted vertically

CTL – Chronic Training Load (Fitness)

CTL represents long-term training load – a rolling average of TSS over approximately 42 days. Rising CTL signals growing endurance capacity; pros often reach 100 to 140 in peak season, amateurs frequently 60 to 90. The rate of increase is crucial: more than 5 to 8 TSS points per week over several weeks increases the risk of overtraining.

ATL – Acute Training Load (Fatigue)

ATL reflects short-term load as a 7-day rolling average of TSS. After hard weeks ATL rises quickly; in recovery phases it drops just as fast. Persistently high ATL with strongly negative TSB signals insufficient regeneration.

TSB – Training Stress Balance (Form)

TSB is calculated as CTL minus ATL. Positive values indicate recovery and race form (+5 to +25 before important races); negative values signal fatigue. The art lies in timing: build load, then reduce deliberately so that TSB is in the target range on race day.

Metric

Time Period

Meaning

Typical Interpretation

CTL

~42 days

Long-term fitness

Rising trend = growing capacity

ATL

~7 days

Current fatigue

Peaks after hard weeks, rapid drop in recovery phases

TSB

CTL − ATL

Form / recovery status

+5 to +25 before competition; negative during load blocks

TSS (basis)

Per session

Daily load

60 min at FTP = 100 TSS

Building CTL Deliberately – Load Management Through the Season

CTL build-up follows the principles of training planning with performance data: gradual increase in weekly TSS, alternating load and recovery weeks, targeted intensity instead of volume alone.

Load Week vs. Recovery Week

In a typical load week, weekly TSS is 10 to 15 percent above the average of the last four weeks. ATL rises, TSB becomes negative. The following recovery week reduces volume by 30 to 40 percent – CTL remains largely stable, ATL drops, TSB recovers.

Week 1
Moderate TSS

Week 2
Rising TSS

Week 3
Peak load, ATL peak

Week 4
Recovery, TSB increase

4-week load cycle: Week 3 marks peak load, Week 4 targeted recovery.

Weekly TSS Guidelines by Performance Level

Athlete Level

Weekly TSS (load)

CTL Target Range (season)

Note

Beginner

250–400

30–50

Focus on consistency, not high peaks

Ambitious amateur

400–700

50–80

3–5 sessions per week, 1 rest day mandatory

Competitive athlete / elite amateur

700–1000+

80–120+

Close coordination with sleep, nutrition, and recovery

CTL alone is not a performance measure. An athlete with CTL 90 can perform worse in competition than someone with CTL 70 and targeted race simulation if FTP is outdated or intensity is lacking.

Tapering with TSB – Bringing Form to Race Day

Tapering reduces training volume in the two to three weeks before an A-race while short intense stimuli maintain performance capacity. The goal is positive TSB on race day without destroying built-up fitness (CTL).

The principle applies from pros to amateurs – see load management before Grand Tours.

Tapering Principles

Reduce volume, keep intensity short – Fewer hours, but 1–2 short intervals or race simulations per week.
Define TSB target – Many time trialists and climbers peak at TSB +10 to +20; classic sprinters sometimes slightly lower.
Set rest days strategically – 2–3 days before the race only very easy rides or complete rest.
Prioritize sleep and nutrition – PMC values reflect training load only, not stress or sleep deficit.

Day 14

Last major load week (ATL high)

Day 10–7

Volume −30 %

Day 6–3

Volume −50 %, short intensity

Day 2–1

Activation only or rest

Race day

TSB in target range

Common Mistakes with CTL-ATL-TSB

Many athletes interpret PMC curves too rigidly or ignore important contextual factors. The following mistakes occur particularly often:

Outdated FTP – TSS and all derived values are calculated too low or too high.
Maximizing CTL only – Endless volume build-up without recovery weeks leads to fatigue and injury risk.
TSB as sole criterion – Positive TSB with low CTL does not mean race readiness at a high level.
Missing session capture – Spontaneous rides without upload distort ATL and TSB.
Ignoring illness and stress – PMC does not know about a cold; subjective feeling and sleep must be assessed additionally.

Checklist: Using TrainingPeaks Effectively

FTP current and verified by test
All training devices synchronized with TrainingPeaks
A-races marked in calendar with priority
Evaluate PMC weekly (CTL trend, ATL peaks, TSB)
Plan load and recovery weeks in 3:1 or 2:1 rhythm
Schedule tapering 14–21 days before main competition
Document subjective feeling (RPE, sleep) in parallel
Recalculate CTL build-up after illness or break

Training Platforms Compared

Comparison of TrainingPeaks, TrainerRoad, and Intervals.icu regarding PMC display, coach features, cost, and indoor integration.

Conclusion

TrainingPeaks turns raw watt data into a controllable load model. CTL shows how much fitness has been built, ATL how tired the body currently is, and TSB provides hints about race form. Those who combine these metrics with current FTP, thoughtful periodization, and honest self-assessment train more efficiently and reduce the risk of overload. The PMC replaces neither the coach nor the race result – but it provides the map on which a successful season is planned.