The definition of Critical Power
Critical Power is the threshold at which the dominant type of fatigue your body experiences changes. This number is used to determine your optimal training intensities (Power Zones) which trigger specific fitness gains and guide your race day effort.
How do I get my Critical Power?
After purchasing Stryd, simply go for a few runs with it. Your CP will automatically generate after a few runs and continue to update as it gets to know you and your fitness improves. This is your first step in moving from traditional training to power-based training.
Note your CP will change often at first as you do more runs and Stryd gets to know you but will slow down over time with more incremental changes less frequently.
Advanced users may want to manually calculate their CP. We provide this option within the app. See instructions here.
How do I know my CP is accurate?
The more variety you have in your running, the more accurate your Critical Power will be. We recommend the following:
Long runs over an hour in duration
Medium distance runs of 10-20 minutes at race intensity
Short distance sprints or strides at max effort (10-30 seconds in duration)
Stryd will use approximately 90 days worth of runs to determine your CP. The runs that contribute to your Critical Power can be viewed in the Power Duration Curve.
Advanced users manually calculating their CP can do Critical Power tests every two-three months and then enter the results in the app. See testing protocol here.
So I have a CP, now what?
Awesome, you now have a snapshot of your current fitness! Your Critical Power determines your Power Zones which are a power range or ‘zone’ for executing different types of runs. Every run will be executed at a different % of your Critical Power. As you push yourself Stryd will see your improvement and adjust your CP and corresponding zones accordingly.
Your CP is 252 Watts.
Your Zone 1 shows as 164 - 202 W.
You should execute your easy run between 164 - 202 W.
The range represents and upper and lower boundary of the zone. You should find an effort that feels easy and the number that works for you.