I would like to define individual number of target sets and/or reps for activities.
This makes the app much more dynamic and also gives the user more flexibility.

Deadlift: 3 sets, 8 reps
Chins: 5 sets, 5 reps
Benchpress: 3 sets, 10 reps

Default number of sets and reps is good, but it must be possible to override this - preferably at both the workout and the individual activity.

-Top level (settings)
--Default sets and reps

--Default sets and reps (overrides the overall settings)

-Individual activity (e.g. deadlift)
--Custom sets and reps (overrides the overall settings and the workout settings)