I have an existing 8020 Ironman plan for run pace and bike power. Have just bought a Stryd and was wondering if I can just use the pace zones in the plan and replace with Stryd power zones (realise they don’t have the X and Y zones)
They define it as “the threshold at which the dominant type of fatigue your body experiences changes.” That’s not helpful in comparing intensity methods. I need some sort of Rosetta stone if I want to compare Stryd zones to 80/20 zones. Is it VT? LT? Anaerobic threshold? Aerobic threshold? CP30? CP20? Could be anything.
Second, even if I could quantify what “threshold” means to Stryd, we may not then agree on what “easy” or “hard” means, or even what “Zone 2” means. Their Zone 2 might include some or all of Zone X, which would be a disaster is you spent a lot of time in Stryd Zone 2.
In summary, no, they are not interchangeable at this time. My advice is to commit to one system or another for the best results. If you commit to Stryd’s intensity measures, you’ll do great. If you commit to 80/20, you’ll do great. If you try and combine them, there is some risk.
I understood your question to be “I can just use the pace zones in the plan and replace with Stryd power zones.” I don’t know how to do that, since I don’t know what the Stryd Power zones are based on (what is Critical Power defined as to Stryd?) So no, you can’t replace 80/20 Pace Zone 2 with Stryd Power Zone 2 at this time. We don’t know the consequences.
But, we can switch you to the Power and Power plan for free, and then you are using our Power zones directly, no conversion necessary. This is the best solution if you are using a Stryd device and an 80/20 plan. Just submit a Level Guarantee at https://www.8020endurance.com/contact/