You're nearly to the finish line! Today, you can choose between complete rest or a celebratory sprint workout. If you still have a lot of remaining energy and feel excited as you near the end of Project Mass, then give today's cardio workout everything you've got. Your improved conditioning should make it a breeze.
Multiple sets of 10-30 second sprints doesn't seem like a lot of work, I know. But don't be tempted to do extra. You've been putting your body through a lot over the course of this trainer, and our goal is building muscle, not shredding. The cardio workouts I've designed will actually do a lot to keep your heart healthy and your muscles growing, despite their brevity.