Variability Index (VI)

Variability Index (VI) provides a deeper insight into the physiological demands of a workout or Event.

What is Variability Index (VI)?

Variability Index (VI) is the ratio of Normalized Power to Average power for a workout or workout selection. The greater the VI, the more variable and less continuously aerobic the effort.

What do I need to calculate VI?

For TrainingPeaks to calculate VI for your ride or segment of the ride we require three things:

1. You need a power meter.
2. A device that records the power channel from your power meter e.g. Garmin, Wahoo, Suunto device.
3. A power threshold that is specific to your completed workout.  Make sure that you have a power threshold set in your account settings.

Where can I find my workout's VI?

Workout Expando Summary

Workout Expando Selection

TrainingPeaks Mobile App

VI reference values

Variability Index for Common Rides