Power Duration Curve (PDC)

What is PCD?

Updated over a week ago

Power Duration Curve explained

The Power Duration Curve is your best effort power (in Watts) at any given duration (up to five hours) that you’ve done over the defined period of time. The view defaults to the last 90 days because that best captures your current ability and is used to determine your Critical Power.

Contributing runs will have a ‘run age’. Runs that are in the last 30 days contribute fully to your fitness model (Auto-Calculated Critical Power Model Curve), after that, they begin to have a deteriorating contribution. Green and gray runs have a diminishing contribution over time (and is the reason you’ll see your Auto-Calculated CP model curve dip below your Power Curve). And gray runs are about to fall off and no longer contribute to your Auto-Calculated CP model. These classifications can help you know what power/duration you need to add to your training to maintain or improve your CP.

Note not every best effort that changes your power duration curve will change your critical power because your CP is a theoretical model based on your Power Duration Curve.

Why default to the last 90 days?

We default to showing the last 90 days because it best represents the period of time that contributes to your Critical Power based on our model for determining CP.

Specifically, if you are not training, 90 days is long enough to capture the effects of detraining, and if you are training, it's long enough to cover the key part of your training plan (e.g., build-up phase and peak phase).

If shorter than 90 days, we may miss some of the training/detraining effects and accumulated adaptation.

Here are some resources to explain the effects of training and detraining...

What is Training Distribution?

This new section is an improvement on the ‘Triangle’ from the old PowerCenter. Whereas the old triangle highlighted your ‘percentile’ ranking, this new feature emphasizes the standard distribution of training by runners with a similar goal. Click into a metric to see what types of workouts to add to your training to see improvement.


A general indication of how your running fitness based on your overall training, derived from your Auto-Calculated CP Modeled Power, or a manual CP calculation. Work on improving all aspects of your PDC to see improvements in your fitness.

Muscle Power

Your body’s ability to generate a burst of power, and derived from the first 10 seconds of the Power Duration Curve. You can test and improve your muscle power with strides and hill repeats.

Fatigue Resistance

This metric is unique to your race goal and represents the amount of maximum amount of time that a given group of muscles can perform at or near the power needed for your target race. Improve your fatigue resistance by running your race effort power for longer durations over the course of your training.

It is possible for your fatigue resistance to go down as your CP goes up because of their relationship.


The maximum amount of time that you are able to sustain running. Typically this should be close to the duration you’re intending to race, but may be longer if you’re goal is a shorter race.

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