Pacing / hyperfocus timers
From the app’s English Help & Guide · Reference release 1.0.19
Time reminders
Add a time limit in the Activity Editor, then start the timer from a planned activity on iPhone or Apple Watch. The reminder is battery-light because it is a one-off timer, not all-day monitoring.
BPM pacing sessions
If the activity has a pacing alert, Apple Watch can monitor BPM only for that session. Metered suggests resting heart rate + 20 BPM when it has enough data, lets you adjust the ceiling before starting, and sends live BPM samples back to iPhone.
One at a time
Only one live BPM activity can run at a time. If you start BPM monitoring for another activity, Metered warns you that monitoring will move to the new session.