In the workout editor, select the exercises you would like to include in the circuit.
Click on the exercise to open the details for the selected exercises.
Here choose "Circuit" from the "Execution" drop down menu and then check the button "In circuit." Press the "Save" button. Back in the main workout editor screen below the "Day" you will see a "Laps" number - this refers to how many laps of the circuit. Insert the number to reflect the number of laps you would like the member to make of the circuit.
Press the "Save" button to save changes.