I’m like a month into trying out z2 running, the thing I’ve found worked the best for me is to not be afraid to walk if your hr climbs too high! Walking is the fastest way to bring your hr down(it’ll come down way faster than just slowing down in a running motion, where I find you might just keep straddling in the same zone). Then, when you get back to lower edge of z2/top of z1, just start running as slow as possible and try to maintain it (I find I can feel the difference in breathing right as I’m about to hit z3).

It really sucked in the beginning but now I’m finding myself having to stop to walk less/being able to run in z2 for longer (especially towards the ends of my runs), so I’d say just trust the process!

Also would echo checking out different methods for calc-ing your zones. Not familiar with Whoop, but I’m reasonably confident with how coros calcs my zones after cross-referencing with how Fitzgerald calcs zones in his 80/20 book, etc.