Most supermarkets and convenience stores are well stocked with neon-colored sports drinks and vitamin-fortified "designer water."
These bottled drinks promise to give the drinker energy and vitality -- some even advertise vague rewards like "balance," "focus" and stress relief.
But does the average consumer derive any real benefit from the sports drinks that Americans spent over $5.4 billion on last year?
Water, Water Everywhere
"It's a marketing gimmick, pure and simple," said Keith-Thomas Ayoob, nutritionist at the Albert Einstein College of Medicine in New York.
Most health experts agree that sports drinks have electrolytes and sodium that are beneficial to professional athletes and marathoners, but have little value to the average user.
"There's a certain appeal in drinking what Olympic athletes drink," Ayoob said, "but it should be just water if you're doing 10 minutes on a treadmill."
And because many enhanced waters contain only small amounts of essential nutrients, Ayoob advises consumers to look elsewhere for nutrition.
"That's what we have food for," said Ayoob.
A Hummer in a Bottle
Other health experts question the sugar and calories these drinks can add to a person's diet.
"It's a way of peddling soda to the health-conscious crowd," said Dr. David Katz, physician and nutrition expert at Yale University School of Medicine.
"If you're in training for the NFL, then having Gatorade at the sidelines is reasonable," Katz said. "But most people use them badly.
"Not only are you not getting any benefit, you're also getting increased calories and sugar," Katz added. "In terms of calories and sugar, just make sure those calories come out of your diet somewhere else."
"It's very much like the commercial for a Hummer or other SUV driving up a mountainside. How many people buying those vehicles are doing that? It's absolutely ridiculous," Katz said.
The Consumer's Responsibility: Choose Wisely
But manufacturers of sports drinks contend their products are healthy and safe.
Craig Horswill, senior research fellow at the Gatorade Sports Science Institute in Barrington, Ill., notes that Gatorade and similar sports drinks are lower in calories than many other beverages.
Gatorade "has fewer calories than sodas and skim milk," Horswill said. He also emphasized that sports drinks are intended for people who engage in sports.
And a substantial body of evidence points to the advantages that sports drinks can have over water for serious athletes.
A recent study published in the New England Journal of Medicine described the condition known as hyponatremia, in which marathoners and other elite athletes can suffer dangerously low levels of sodium in their blood due to over-hydration with water.
But not all sports drinks provide enough sodium to offer real protection from hyponatremia. This year, Gatorade is introducing a new beverage called Gatorade Endurance Formula, with more sodium and potassium than its regular formula.
But ultimately, many in the industry say consumers must decide for themselves whether to use sports drinks as part of a serious exercise regimen, or just a sugar-laden soda substitute.
"Gatorade is formulated for the performance and the safety of the athlete," Horswill said. "The biggest issue is exercising and being more physically active, instead of focusing on diet. Consumers have to be aware of what they're consuming."
Others in the the industry also put the onus on the consumer to make smart dietary choices.
"Fundamentally, people who have sedentary lifestyles need to make choices," said Ray Crockett, spokesman for the Coca-Cola Company, maker of Powerade and other sports drinks.