Endurance athletes and coaches often talk about polarized vs. non-polarized training. But what does this actually mean, and how can you quantify whether a training program is polarized or not? A new metric called the polarization index (PI) aims to provide some clarity.
The polarization index is a simple calculation that looks at the distribution of your training time or distance across three intensity zones:
- Zone 1: Low intensity
- Zone 2: Medium intensity
- Zone 3: High intensity
To determine the PI
PI = log10(((Zone 1 / Zone 2 )* Zone 3) * 100)
If your PI is greater than 2.00, your training distribution is considered polarized. This means the majority of your training volume is spent in Zone 1, with less emphasis on Zones 2 and 3. Non-polarized training distributes volume more evenly across the three zones.
Research has shown that elite endurance athletes tend to follow a polarized training model. Their high volume of low intensity training allows them to absorb the hard workouts and adapt to get stronger. But what PI is ideal? There is no perfect number, as it depends on your specific sport and goals. The PI simply quantifies your polarization.
So in summary, the polarization index is an easy way to calculate whether your training is polarized or not based on time or distance in three intensity zones. It provides an objective measure you can track over time as you refine your training plan for optimal performance. Give it a try!
You can find the PI index in the activity analysis and in the calendar view of the SELFLOOPS website.
Reference
Treff, G., Winkert, K., Sareban, M., Steinacker, J. M., & Sperlich, B. (2019). The Polarization-Index: A Simple Calculation to Distinguish Polarized From Non-polarized Training Intensity Distributions. Frontiers in physiology, 10, 707. https://doi.org/10.3389/fphys.2019.00707