I have been dieting for a show and cycling carbs. I have noticed that on the days after I take in carbs the clen seems to really give me a boost of energy and heat me up real good. When my glycogen stores are depleted it seems the clen has almost no effect, no energy, no body temp increase, just the shakes and a little tight or cramping feeling in muscles recently trained. So i tend to beleive that clen is actually most effective on a low to moderate carb diet and seems almost worthless to me on a 0 carb diet. Anyone with any input?