I’m following the TuffCuff program, and it says for arms, you have to lift light. But how light is that? Like maybe around 70% of what you normally lift?
You can do whatever weight you want, as long as you can complete the listed repetitions with good form. Tuffcuff only has about two arm workouts per weightlifting session, so be afraid to go heavy.
However, always use light weight (2.5-5) when performing the rotator cuff exercises.