Pre-set the monitor for a work time of 12:00 and a rest time of 4:00.Let your stroke rate vary as follows per interval: First interval: 5 minutes @20, 1 minute @24, 5 minutes @22, 1 minute @26 Second interval: 4 minutes @20, 2 minutes @24, 4 minutes @22, 2 minutes @26 Third interval: 3 minutes @20, 3 minutes @24, 3 minutes @22, 3 minutes @26 Fourth interval: 2 minutes @20, 4 minutes @24, 2 minutes @22, 4 minutes @26. During the rest time continue rowing at light pressure.