Long Interval Workout

Choose ONE of the following sports:
Swim 4:00 on, 4:00 off, 4:00 on 3:00 off, 4:00 on, 2:00 off, 4:00 on, 1:00 off, 4:00 on
Bike 4:00 on, 4:00 off, 4:00 on 3:00 off, 4:00 on, 2:00 off, 4:00 on, 1:00 off, 4:00 on
Run 4:00 on, 4:00 off, 4:00 on 3:00 off, 4:00 on, 2:00 off, 4:00 on, 1:00 off, 4:00 on
Row 4:00 on, 4:00 off, 4:00 on 3:00 off, 4:00 on, 2:00 off, 4:00 on, 1:00 off, 4:00 on