Wow, this is so awesome! Sounds like the perfect situation for you. Congratulations!
The point is to make it aerobic, which pretty much means constant, to get to the 80% for 30 mins. Some people’s city walking is start and stop (at corners.) If yours is sustained, fine. But you can’t check heart rate while walking, without some gizmo. And I can’t imagine yoga is aerobic. Maybe that’s for relaxation and “Mindfulness.”
Both are why I like the gym treadmill. No need to watch the sidewalk, the handgrips measure pulse.
OK thank you for the PM suggestion of the Enell bra. Gonna give it a try!