CoachingAnswer

WHAT IS CTL IN TRAININGPEAKS?

By Anthony WalshRoadman CyclingUpdated 20 June 2026

WHO THIS IS FOR

IS THIS YOU?

The rider building toward an event

You want to know whether your fitness is genuinely climbing as your event approaches.

The data-curious amateur

You see a 'CTL' line in TrainingPeaks and want to know what it's actually telling you.

THE ROADMAN VIEW

CTL is the closest thing you have to a single dial for fitness, and its slowness is its strength. A 42-day average can't be faked by one heroic weekend or wrecked by one missed session. It rewards exactly the thing that actually builds cyclists: consistency over months. That's why the line you want to see is a patient, steady climb, not a spike.

The number itself means little in isolation — a CTL of 70 is meaningful for one rider and modest for another. What matters is your own trend and your own ramp rate. Push CTL up too quickly, by ramping your weekly load hard, and you build fatigue faster than you build fitness; let it slide for weeks and the engine quietly shrinks. The art is a sustainable rise, with recovery weeks that dip it slightly so the next block lands.

And CTL only earns its keep alongside its siblings. On its own it tells you how big the engine is. Read against ATL (fatigue) and TSB (form), it tells you whether you can actually use that engine right now. It's one line in a three-line story.

EXPERT EVIDENCE

WHAT THE EXPERTS SAY

Joe FrielCo-founder of TrainingPeaks, author of The Cyclist's Training Bible
Fitness is built slowly and consistently, which is exactly what a long rolling average captures. The value of a chronic-load line is that it ignores the noise of any single ride and shows whether the training is genuinely accumulating over time.
Hear it: The Training Secret To Going FASTER After 40 | Joe Friel

PRACTICAL APPLICATION

DO THIS WEEK

Track the slope, not the number
Open your Performance Management Chart and look at whether the CTL line is rising, flat or falling over the last several weeks. Rising means you're building; flat or falling means you're maintaining or detraining.
Ramp it sensibly
Aim for a gradual rise across a build, with a recovery week every third or fourth week that lets the line dip slightly. A steep, relentless climb is a fast route to a fatigue hole.
Use it to plan a peak
Build CTL through your training block, then in the taper hold it roughly steady while fatigue drops — that's how form arrives on the day.

COMMON MISTAKES

WHAT CYCLISTS GET WRONG

MISTAKEChasing a higher CTL number for its own sake.
FIXA bigger number built on unsustainable load just buries you. Aim for a steady, recoverable rise, not a record CTL.
MISTAKEPanicking when CTL dips during a taper or rest week.
FIXA small CTL drop while shedding fatigue is exactly what should happen. You lose a little fitness to gain a lot of freshness.

FAQ

FREQUENTLY ASKED QUESTIONS

What is a good CTL for a cyclist?

There's no universal good number — it's relative to the rider and the event. Many amateurs ride strong sportives and races with a CTL in the 60s to 80s, but what matters is your own trend, not comparing your figure to someone else's.

How fast can I raise my CTL?

Sustainably, only gradually. A modest week-on-week rise in training load is what builds CTL without digging a fatigue hole. Spiking your weekly TSS to force CTL up quickly usually backfires within a couple of weeks.

Does CTL equal fitness?

It's a good proxy for the size of your aerobic engine, but it's not the whole story. CTL says how much training load you can carry; it doesn't capture freshness, sharpness or event-specific skills. Read it alongside ATL and TSB.

Will my CTL drop on a rest week?

Yes, slightly, and that's intended. A recovery week reduces load, so the 42-day average dips a little. The fitness isn't lost — the brief dip lets accumulated fatigue clear so the next block is productive.

How much CTL do I lose when I stop training?

CTL falls gradually because it's a long average, so a few days off barely register. Longer breaks see it decline steadily, but it also rebuilds faster than it built the first time once you return to consistent training.

What's the difference between CTL and ATL?

CTL is a 42-day average representing fitness, so it moves slowly; ATL is a 7-day average representing fatigue, so it moves fast. The gap between them is your form (TSB). Together they show whether your engine is big and whether you're fresh enough to use it.

RELATED EPISODES

HEAR THE CONVERSATIONS

The Training Secret To Going FASTER After 40 | Joe Friel

80/20 Training to Ride Faster | Dr Stephen Seiler