Can millions of celebs, hipsters and Bikram practitioners be wrong?Turns out, trend slaves and hot yoga devotees may be devastated to learn that coconut water, the drink of choice purported to replenish lost electrolytes more efficiently than traditional sports drinks, may not be all it’s cracked up to be.

A report issued by tested the contents of the most popular coconut water brands and found that only one, Zico Natural, contained the stated amount for all four electrolyte ingredients.While all contained plenty of potassium—about 25 percent more than a banana—they found the other ingredients lacking. Of most concern to those who depend on coconut water’s so-called powerful hydration benefits to keep them safe during sweaty workouts might be the fact that the researchers found that key electrolytes sodium and magnesium were as much as 82 percent and 35 percent lower, respectively, than the listed amount.

Specifically, sodium in the coconut waters ranged from just 11 mg (in a 330 mL suggested serving) to 160 mg (in a 414 mL suggested serving), whereas say, a good old-fashioned Gatorade contains 110 mg of sodium per cup (8 fluid ounces or 240 mL).But the real bottom line here is this: The average person does not need to drink electrolytes anyway. “The idea of the sports drink or electrolyte drink for the everyday person is a myth,” explains Kristin Kirkpatrick, R.D., YouBeauty Nutrition Advisor. “Unless you are an athlete, or are working out hard for over an hour, you don’t need it.”

Kirkpatrick also points out that while sodium is an important electrolyte for people who are training for a sport, or are consistently active outside in hot temperatures (or if you’re a Bikram junkie), most people get more than enough sodium in their diets and there’s no need to replenish it.The moral of the story: If you love coconut water for the taste (or you are Rihanna getting paid to hawk it on a billboard), go for it. But if you’re an everyday Jane, you can pass on the “instant hydration,” no matter how cool those blue bottles make you look.

MORE: How Much Water Do You Really Need?