[extantproject]

As a recovered Mountain Dew head, I agree. The sugar in Mountain Dew is the worst of it. I used to require five or so Mountain Dews every day. When I slowly stopped drinking it (I switched completely to coffee to avoid caffeine withdraw) I stopped getting really hyper then crashing five times a day. My concentration is much better without Mountain Dew. It took me about five weeks to switch (one less can per week).

Not too long afterward I got my caffeine intake down to whatever is in two to four cups (or shots of espresso) of coffee a day, where it's been ever since.

Now, a few years later, I'm in the process of limiting myself to two cups (or shots of espresso) a day. I'm down to three, but it's fairly difficult to go lower -- which sucks.

Don't drink all this shit! Drink water and sleep when you're tired; maybe have a cup of coffee a day. Your concentration will be much better. There's natural variance in energy levels throughout the day. Stimulants just make the highs higher and the low lower -- but they also make the highs shorter and the lows longer. Check up and really pay attention to yourself through the day -- you'll likely want to reclaim your energy back from all these supposed "energy drinks" and other garbage.

[stuki]

The way I learned it is the natural alertness cycle is sinusoidal, and by taking stimulants strategically timed one can square it off. That way one can increase total hours of close to peak alertness, as well as make sleep deeper and heavier.

[extantproject]

I generalized my personal experience. It may be different for different people, but I'm tired longer the more I use stimulants. But I've also had one to two cups of coffee in the morning every day for about four years now. If I drink more at other times I generally feel worse for a longer period of time and don't gain much in the way of concentration.