Yes, breaking up is hard to do. But then again, it's the best attitude to have when working out if you want to be more efficient at burning calories.

Why not take two back-to-back 30-minute workouts when doing that treadmill or elliptical cardio workout? Instead of going for an entire hour, try splitting up your session with a 20-minute rest in between.

Combine cardio and weight training in a single workout as well, but just don't combine the sessions without a break. That is, if your goal is to get those calories burned with the best combination of effort and efficiency.