Supplements definitely expose a weakness in my knowledge base. I'll tell you that right from the get go. Seeing as how even the most 'worthy' supplements make so little difference, I just haven't been very passionate about staying abreast of the field. I encounter very few people who have the basics dialed in entirely... and they'd get a lot more mileage out of improving those things.

Worrying about supps when the foundation of basics isn't cemented is akin to putting an exhaust system on an '87 honda civic, haha.

Let me start by saying the only supplements I use are protein powder, fish oil, a multi, and vitamin D. I've also used creatine off and on over the years. I've found that I'm not that much of a responder to it... but for those who are, I think it's a great supplement.

I've recommended calcium supplementation to clients who aren't big on dairy.

I have zero experience with fat burners. Meaning I've never used them myself.

I'll say this though. If I were to use them, I'd get my hands on ephedrine. I'd take this in conjunction with caffeine. It has reams of research supporting its safety and efficacy and it was banned for political reasons. It's great at blunting appetite, increasing fat mobilization, and offsetting some of the metabolic slowdown that occurs with dieting. Granted, I wouldn't recommend it to anyone with contraindications such as heart and blood pressure issues. And I wouldn't recommend it to anyone who might have a tendency to abuse it.

At the end of the day though, most fat burners are stimulants and any stimulant has the ability to make you jittery.

I'd ditch the L-Carnitine... research hasn't supported it's efficacy. CLA is questionable too. While there is some positive data out there, it's only minorly positive and not worth the cost if you ask me.

Green tea has been shown to increase fat burning. There's some conflicting data out there... but the majority of it is pointing toward this being the case.

In terms of pick-me-ups before training, I've been hearing great things about this:

http://www.citadelnutrition.com/pre-workout/tier-1

If it were me though, I'd likely turn to caffeine yet again. Granted, I'm not all hopped up on it as I don't drink caffeinated drinks. Therefore, I'm much more sensitive to it. But it's cheap and effective.

A reduction in caffeine can definitely be playing a role. If it's really dragging you down and impacting gym performance, I'd highly suggest supplementing with caffeine.