At our office, we are fortunate to have both a gym and a trainer come in from a local gym to lead boot camp-style fitness classes. We do a different workout every day, focusing either on Push muscles (Chest, Tris, Quads), Pull Muscles (Back, Bis, Hamstrings/Glutes), and Cardio.
This workout was a true test of my discipline: 25 reps of burpees alternated with 25 reps of a core exercise for a total of 500 burpees and 500 core reps. It took just over an hour but it was a great beginning to my day. If you want to challenge your discipline, I would encourage you to try this out.