Look for energy pills, not fat burners. I never ever seen any fat burner that has test of how many calories it will burn for you. I have seen Doctor Prescribed fat burning pills work but they are given to only the morbidley obese.
Get an energy pill that works for you, the extra boost may help you last longer during your cardio sessions. I'd recommend any ECY stack you can get your hands on really, standard 25mg of Ephedra and so on.
Oh, and water, lots of water. I find I get more energy during the day with the more water I drink. But here is a tip, don't drink a lot of pop during the day then next day start drinking a lot of water. You'll piss until they try to make your wang a Hydro Plant.