If you're a long-distance runner or cyclist, you've probably had someone tell you that endurance sports are all about "mind over matter". And it's true: Mental strategies can help you power through the pain. Just like training for strength and size, you can train yourself for mental toughness.

But leave it to science to take a simple expression to the next (and somewhat unsettling) level—by throwing "transcranial direct current stimulation" into the mix.

Yes, you heard that right. Transcranial direct current stimulation is science-speak for stimulating the brain by passing a mild electrical current through your skull—and it can actually improve overall athletic performance, according to a new study published in the journal Brain Stimulation.

In the study, researchers studied 12 cyclists and found that the "stimulation" increased the brain activity of the area associated with muscle contraction, which decreased the perception of effort and increased how long the cyclists could pedal for.

And while this may sound like something out of a sci-fi novel, it's not. A start-up called Halo Neuroscience has created a device—the Halo Sport—that looks very similar to a pair of headphones and supercharges your brain with similar electrical currents used in the study. The only catch? You'll need roughly $600 to nab one—and to be unafraid of zapping your brain, of course.