If I can get through the workout without needing to take a break, does that mean that I am not working hard enough?

Probably. Watch the videos. Even the trainers take breaks, and they are some VERY fit individuals. The entire point of the program is to force you to take breaks. If you can get through the full fifteen minutes without stopping, try pushing a little harder or add bands or dumbbells and see what happens. We think you will find you MUST rest! And your results are likely to improve as well.