Maybe you didn't sleep so well last night, with an unruly spring poking you in the back and your clock ticking thunderously. Perhaps the massive burrito you ate for lunch is now singing the refrain to "Cielito Lindo" over and over as you lapse into an afternoon food coma. Or your boss "suggests" that you stay late to finish the maddeningly boring last bits of the big project. You need a boost to jolt yourself out of your lethargy and amplify your productivity.

Well, you can overclock a PC for better performance, so why not overclock yourself? Is there a simple way to speed up your metabolic rpm, accelerate your mental gigahertz, or increase your intellectual bandwidth? And can you achieve the performance upgrade without shorting out your power supply or overheating and fusing your CPU, thereby transforming yourself into a featherless bipedal doorstop.

In the interest of semiscientific inquiry--and because I'll eat just about anything to put food on the table (wait a minute...)--I took a look at a host of performance enhancers from the mainstream to the exotic to the just plain wacky. My mission: to see which ones provided a boost without inducing psychosis. For each product, I ingested a standard serving in the morning, in lieu of coffee. Enduring the resulting jitters, shakes, nausea, hallucinations, palpitations, and heebie-jeebies, I sweated out the bad stuff to bring you the good stuff.

Though the efficacy of all of these supplements remains largely a matter of conjecture, energy drinks are at the center of a growing controversy over the unknown effects that large quantities of herbal energy boosters can have on the human body. I can't stop you from trying any of these products, but I urge you to exercise caution if you're inclined to experiment--and not to experiment at all if you are under 18, are pregnant (or trying), or have any health problems. With that caveat out of the way, here's the straight dope on so-called smart foods. And remember: I'm not a real doctor.

Drinking It All In

The most accessible over-the-counter power-up--and perhaps the most controversial--is the energy drink. If you're looking for a quick jump-start, just crack open one of these stimulant-rich solutions. Packed with potent pep in the form of sugar, caffeine, and guarana, plus vitamin C and B vitamins, energy drinks can deliver an undeniable boost. But are they safe? Few topics in the nutrition world are more hotly contested.

Cynthia Sass, a registered dietitian who holds a masters degree in public health, says that it all depends. "Caffeine is generally considered safe, but when multiple stimulants are combined, even healthy, young, fit people can experience side effects including spikes in blood pressure and heart rate," says Sass. And energy drinks do pile on the stims. Guarana includes its own hidden dose of caffeine but is listed separately from regular caffeine; ginseng is another natural stimulant. In addition, the gargantuan cans that energy drinks are sold in usually contain two full servings (and sometimes more), so it's easy to exceed a dosage that's comfortable or safe for you.

Of course, the drinks themselves vary widely in flavor and efficacy. As you wander the minimart before your second shift, you encounter a visual cacophony of mysterious concoctions that evidently target very precise subgroups of the sleepyhead demographic, ranging from NASCAR moms to death-metal tweens. Which one should you consume to replenish your essences? I grabbed several of the most popular drinks (sans the ubiquitous Red Bull; I figure that if you're interested in it, you've already tried it) to test the effects--good or bad--on my own physiology.

(Confused about the vaguely medicinal-sounding herbal additives--such as taurine, guarana, and L-carnitine--that crop up in the lists of ingredients? Jump to the "Field Guide to Energy Additives" for a primer on these ingredients.)



Nos High Performance Energy Drink

Taste: 8

Energy: 2

With its low carbonation (typical of energizer drinks), Nos resembles a peach Orangina, making it pretty pleasurable to drink. When cold, it verges on refreshment. It comes fortified with caffeine, ginseng, taurine, and both vitamin C and the B group of vitamins. But in my test, its energy boost seemed rough and short-lived. It certainly increased my energy and awareness, but those effects were attended by a shakiness that was better suited for staccato tapping on a tabletop than typing an e-mail. In short, it was a jaggy rush followed, inevitably, by a case of the yawns.