Jolt, Blitz, Hype, Rush, Burn, Crunk, Amp. The catchy names translate into a rush of energy for consumers and a flood of contentment for retailers

Energy drinks have had breakaway success since 2002, with sales growing from $111 million to $636.8 million in 2006, according to the latest figures from market research group Packaged Facts.

Red Bull, arguably the best known of the beverages, has charged ahead in the market since its first can was sold in Santa Cruz, Calif., in 1997. The company has a policy of not releasing specific regional sales figures, but spokeswoman Patrice Radden said more than 4 billion cans of Red Bull were sold around the globe last year.

As the market grows, Red Bull is adding products, such as the Energy Shot, a 2-ounce pick-me-up to gulp on the go.

Even Chattanooga-based fast-food chain Krystal has joined in with Blitz. The energy drink premiered in late July after research showed a growing market for the beverages.

“It piqued our interest,” said Brad Wahl, vice president of marketing.

Sales are strong, he said, and drinker demographics include not just the teenagers originally targeted but also men and women in the 25-to-45 age range.

“Appeal has been broad, and our operators have been very pleased with the response,” he said.

Energy vs. health

Despite the popularity of the drinks, there’s a movement to quench the temptation to overindulge.

Too much caffeine can get you in trouble, said Lea Reagan, registered dietitian and certified diabetes educator at Memorial Hospital’s Diabetes and Nutrition Center,

“When your caffeine intake gets too high, we get concerned about hydration issues because caffeine can act as a diuretic,” she said. But there are other health factors to consider, she said, including weight gain, heart arrhythmia and insomnia.

“When people are hooked on caffeine, they can get headaches and jitters,” she said. “This may make people think they are hungry and need to eat, which can lead to weight gain. To be safe, limit your caffeine intake to 200 milligrams a day. Anything over 350 milligrams a day can cause dependency on caffeine. It’s no different than drinking a lot of Coke or coffee. They can be deceiving. If you’re drinking a six-pack a day, you can run into problems.”

Ms. Reagan also cites an article from Johns Hopkins College of Medicine calling for warning labels for energy drinks because of the nation’s caffeine intoxication.

“And there is growing incidence of young people mixing energy drinks with alcohol to get a quicker high because energy drinks speed up the metabolism and heart rate and make alcohol get in the system faster,” she said.

Victoria Underwood, 28, said she interrupted her daily intake of at least two sugar-free Red Bulls when she became pregnant with her now 9-month-old son.

“I didn’t know how I was going to make it through my pregnancy without them, but I did,” she said. “I really feel like if I don’t drink them I’m more sluggish. I don’t know if it’s a mental thing or not, but if I don’t drink them, I won’t wake up.”

Ms. Underwood, who works at the Insyde Outsyde Shop in Red Bank, said she doesn’t like the taste of coffee, so she downs her first Red Bull to wake up in the morning.

“Then I start feeling sluggish again around 3 o’clock, so I have another one,” she said. “It really does work for me.”