Nath

I ussually take ECA stacks about 40 mins to 1 hour before a workout, I start to feel them 'coming on' about an hour after taking them, although I do take pretty strong ones. I have had grenades and found I needed at least two of them for them to give me a boost for my workout. You probably don't need a 'buzz' in order for the tabs to give u a thermogenic effect. I think ur best bet is trial and error. If ur not feeling it, take 2. I'm not sure how strong those grenades are, but peoples reactions differ. That is why I like the chesteze method as I feel I can tailor my dose perfectly. A lot of people who I know take grenades and they will take three and I've heard of one dude hammering 4 down his neck!! (def wouldn't advise this) U may find that with prolonged use, the affects will diminish and you may need to up ur dose. I try and stop using them when this happens and have about three months off.