To the untrained eye, they are simple rubber bracelets with a plain metal clasp. But ask some of the professional athletes who are endorsing them, and they will tell you that Power Bands give your performance the extra boost it needs.

Needless to say, there’s no scientific evidence that proves these bracelets do anything more than adorn your wrist. That hasn’t kept thousands of sports enthusiasts from snapping them up, at a price of twenty-nine-ninety-five per band.

In case you haven’t seen one, a Power Band is a bracelet made of neoprene or rubber. It comes in different colors and has a stainless steel clasp. But manufacturers say what makes it special are the two small hologram stickers that are supposed to interact with the body’s natural energy to improve strength, balance and flexibility.

Sound far-fetched? Several famous athletes wear the bands, including basketball star Shaquille O’Neal, football player Drew Brees and Olympic skier Bode Miller. And the manufacturers’ claims aren’t completely off-base: The body does have some electromagnetic properties. Muscles expand and contract because of electrical impulses sent by the nervous system. In fact, one of the tools used by physical therapists is intense electrical stimulation to heal muscles and mend fractures.

But is the energy created by two small hologram stickers big enough to make a difference? That’s unlikely, experts say.

Numerous stories have been done on the power of placeboes. In other words, if an athlete thinks something is helping him or her, it does. However, this effect typically wears away over time.

The bottom line: If you like the bracelet, go ahead and buy it. But get it because you like how it looks, not because you want superior athletic skills.