Something I'm enjoying on the #whoop free trial I'm doing is the heart rate zones. I'm running trying to hit them based on my stats for the day (HR, HRV, sleep, menstrual phase etc) and it's going well. I actually end up running more controlled and less effort than normal which feels good knowing I'm Doing It Right instead of guessing. Feels more like training, less like phoning it in.

(Free 4 week trial link > https://join.whoop.com/D1C1DA1F fake 'cancel' to get 2 extra weeks as well)