Energy supplement?!

Energy supplement?

I'm interested in finding the best energy supplement available on the market for long days at work. My job is extremely strenuous and physically challenging. Any ideas?

i like green tea and acai berry juice. i am a full time student and martial artist and recently, i have been finding that drinking acai berry juice (many brands mix it with a blend of guarana and/or yerba mate for a caffiene kick, too) allows me to make it through a day of mental activity and a tough training session at night. this, of course, has to be coupled with proper eating habits and rest. there is no substitute supplement for that; proper recovery time and rest is essential. plus, the acai berry is full of antioxidants and omega fatty acids. i also like mangosteen. many of the energy drinks out there are crap for your body, are way too acidic, and have way too much sugar and/or caffiene. green tea in the am with bfast, take an acai berry juice on the way to work and one during the day if you need a boost. if you can find the acai berry juice with mangosteen in it, then thats even better (thats what i like anyway).