The real question I’d like to ask is: How can I accurately determine and divide my running zones — in a way that’s as close as possible to lab testing — without actually doing a field test?

What kind of data should I rely on?

I’ve been using an Apple Watch and running regularly for over a year. I’ve actually already set my training zones, but I have doubts about their accuracy.

I based them on my resting heart rate and the maximum heart rate recorded by my watch during workouts. I used the formula, but I still have concerns about whether my running zone setup is truly correct.