A personal trainer at my gym recently recommended that I put my cardio between excercises. Sounded bizarre. I was doing my lifting, then cardio at the end. Now it is a game- do an exercise, hit the stair stepper for 5 min. Another exercise, hit the elliptical for 5 min. Another exercise, hit the treadmill for 5. With the variety of the cardio and weights melded into once continuous workout, I am dropping weight and it feels obvious that is it a much tougher workout. It also shortens your rest time- as soon as you are done lifting, you know to get your @ss over to your little cardio session. I really didn't have much faith in it but I am glad I tried, and it also makes the workouts feel short and intense- even though they are the same length.
Best of luck in your contest, and congratulations on achieving that level of discipline!