A Live Activity carries the whole set cycle. One tap logs it, the rest timer runs itself, and the countdown ends with a tap ready for the next set.
State 1 is live — tap Log set to run the cycle.
The compact island keeps the set ring and countdown in the corner of whatever else the phone is doing. Press and hold, and the full controls expand.
The same Live Activity surfaces on the wrist automatically. No watch app to install, open, or keep charged enough to matter.
The lock screen logs your target as-is. If the set went differently, the correction happens in the app. On the gym floor, one safe tap beats a locked-out form.