I second the ECA (Ephedrine [bronkaid], Caffeine, Aspirin) stack BUT you have to be really careful with the heart rate. Cool thing about it is it actually works while your stagnant, meaning it raises internal body temperature to a thermogenic phase (that phase one reaches after 15 mins of work out) and you immediately start dropping. Again, WATCH THE HEART RATE!!!!.
Oh yeah, and make sure you eat. Huge appetite suppressant. Lastly, try not to drink anything acidic or sugary while on this because it actually counter balances the stack and neutralizes it rendering it ineffective. The Stack primarily works by lowering your sugar and raising your body temperature. This is aside from stimulating your B-Agonist receptors and other crap.