Pauses in reps can be very useful for building muscle mass and practicing strict form, especially when doing higher reps or exercises where you tend to zone out or speed through. Pauses at the bottom of each rep helps keep you aware of your form as well as letting your muscles re-engage for the second part of the lift. Pause reps can be a great way to add more difficulty to your workouts, but it’s best to assess each lift to see if it will be beneficial.