I (accidentally) clicked the “?” button next to Joe Friel Run in the run Pace Zone settings presets drop down:
It tried to open https://joefrieltraining.com/a-quick-guide-to-setting-zones/
, but I get a “Page not found” error. A quick search of the site brings up https://joefrieltraining.com/a-quick-guide-to-setting-zone/
, so it looks like the link on intervals.icu has a typo (“zones” instead of “zone”).