IVE DONE HYDROXYCUT IN THE PAST AND IT MAKE ME REALLY SHAKY AND SWEATY, AND I FELT LIKE IT WAS WORKING...BUT NOW IM ON THE CLENBUTEROL AND IM NOT SHAKING THAT MUCH AND NOT SWEATING AS MUCH AS I WAS ON THE HYDROXYCUT......DOES THAT MEAN ITS NOT WORKING.....OR DOES THE CLENBUTEROL CUT FAT IN ITS OWN WAY??? ANOTHER QUESTION IS...I KEEP HEARING GUYS MENTION ECA....WHATS ECA?