Running off Stryd power and using an 80/20 plan, my critical power is currently 325w.
This puts zone x, for steady state runs, at between 295w and 305w. I know I can hold up to 315-320w over a half. But my long runs are usually done around 270w as my mileage increases.
Question is – given how difficult I am finding the long run – do I pace my marathon in zone x, or do I go low to mid zone 2?
Most runners can manage low Zone X for a marathon and that’s my go-to recommendation. What you describe is consistent with that. Zone 2 is reserved for very conservative or new runners. See our guide https://www.8020endurance.com/race-pacing/ for more information on pacing, and even our complete section on pacing at https://www.8020endurance.com/resources/ which has multiple documents for marathon pacing.
Ah superb! Thank you!
Following on from this thread and David’s advice above that managing zone X for a marathon is do-able – what about Half Marathon?
I have a race on Sunday. Its a B Race as i am in the middle of training for my first Ironman in July.
Pete, see that same table at the bottom of https://www.8020endurance.com/race-pacing/ Zone X is the perfect zone for HM racin.