Instead of reps, perform the exercise for the specified amount of time.
Rest:
Specified amount of rest time before performing another set (or) moving to the next exercise.
Circuit:
A group of exercises that are completed one after another. Each exercise is performed for a specified number of repetitions or for a set time before moving on to the next exercise.
Workout Instructions
Circuit
Perform each exercise in this circuit one after another. Rest for the specified time period between exercises. Repeat the entire circuit 5 times before ending your workout.