"Under certain circumstances, they may be appropriate," Castriotta says. "If you're flying a B-2 bomber from Missouri to Afghanistan and back, you're allowed to take a drug. But once you get back to base, you don't continue to take those drugs."
The same advice pertains to our everyday lives, he says. Take them in a crisis -- when you need to put in extra hours on a big project -- then quit.
The energy-boosting drinks -- Red Bull, Jolt, Lizard Fuel, Mad River Energy Hammer, Red Devil Energy Drink, Sobe Adrenaline Rush -- are just craziness, says Leslie Bonci, MPHRD, director of sports nutrition at the University of Pittsburgh Medical Center.
"If you drink this stuff and are on the ceiling, don't be surprised," Bonci tells WebMD.
The drinks "have huge loads of caffeine -- much more than a Coke or Pepsi," she says. Trouble is, most people drink more than one. Then, when it's finally time to get some sleep, they're so wired that sleep is impossible. "Your mind is circling the room 25,000 times."
Sensitivity to caffeine in any form -- including pills such as No-Doz -- depends on the person, says Bonci. "Your heart may be racing more than otherwise, you can get an acid stomach. Caffeine can also have a diuretic effect, a fluid-losing effect. Yet you're not giving the body any fuel [any food] whatsoever. So when it wears off, the body is in shock. So you're even more tired."
To really give your body an energy boost, grab a glass of orange juice or a handful of pretzels, she advises. "A lot of times, people are not eating regularly. They grab a Red Bull instead of food. [An energy drink] is not a substitute for real energy food."
In the long term, we simply need sleep, say the experts. Sleep is complex, and despite all the research, no one really understands why we have REM and non-REM sleep cycles. "There's a need, a reason why we have a drive to sleep," says Castriotta. "We suspect that there's a major immune function to sleep and immune impairment from lack of sleep."