Mind over matter: Ultrarunner Dean Karnazes's brain-training device

Ultrarunner Dean Karnazes once ran for 82 hours straight, covering 350 miles. When you have to run that distance in training each week, your mind can be either your best friend or your worst enemy. That's why Karnazes has been using a high-tech device that trains his brain to sleep better and more efficiently. 
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When ultrarunner Dean Karnazes needs a mental boost, he plugs in, powering up with a device that looks and feels like something from a science fiction movie. Karnazes connects to a mind-altering gadget called Thync that hooks up to your brain—or at least sticks onto your head in order to theoretically alter your mood. But perhaps the strangest thing about the device is that it actually works. “You press a button and you feel great,” says Isy Goldwasser, Thync’s CEO and co-founder, explaining his company’s philosophy of making the body’s internal systems controllable through technology.

“I’ve tried Red Bull … there are other stimulants like that,” Karnazes says, “but this is something completely different.”

When you have to run hundreds of miles in training each week, and spend days out on roads and trails competing—Karnazes once ran for 82 hours straight, covering 350 miles—your mind can be either your best friend or your worst enemy. “It’s you versus you,” Karnazes says. “It’s self-confrontation. It’s you overcoming your perceived limitations and pushing through pain barriers that you’re not sure you can get through.”

Thync works by pulsing small electrical currents, no more than about 20 milliamps, through nerves on the head. A sticky strip of electrodes attaches to places where nerves run close to the skin above the right eyebrow, behind the ear, and on the back of the neck. A small triangular device connects above the eyebrow, and sends electrical pulses out through the electrode strip. According to Jamie Tyler, Thync’s CSO and other co-founder, the effect of pulsing currents along these nerves is to modulate norepinephrine production in the brainstem at the back of the head. The device has two main modes—called "vibes" in Thync-speak—calm and energy. The difference between these two is that energy increases the release of norepinephrine, increasing alertness, whereas calm decreases it.


​The strength of these effects varies from person to person, but 80% of people experience a strong response, according to Goldwasser. However, not everyone enjoys the mind-altering feeling. “My immediate response was to tear this thing off my head,” Karnazes says of his first experience. “What am I doing to my brain?”

But Karnazes kept using Thync, and became a convert. The greatest edge he found, though, wasn’t from the attention-boosting effects of the energy vibe, but from the relaxing effects of the calm vibe. “I use the calm for sleeping at night, recovery,” Karnazes says. “For an athlete, sleep is really important, and disruptive sleep is really a hindrance to your recovery.” After using Thync for the last five months, Karnazes has found that it helps him fall asleep quicker and wake up less during the night.

“The biggest impact we’re going to have for athletes, especially pro athletes that have really demanding workout routines and travel schedules, is to help them sleep better,” Tyler says. The Golden State Warriors won last season’s NBA Finals 4–2, in part because Cleveland Cavaliers star forward LeBron James was struggling with fatigue. If James had been fully fit and rested, maybe history would have worked out a little differently.

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​Tyler can also design personal vibes. “If you have a very high pain threshold, you can tolerate more,” Tyler says, “and we can actually make the effects stronger that they are right now.” By tuning the power and frequency of the electrical pulses, Tyler can learn which settings work best for Karnazes, and individualize the effects.

However, if this sort of electronic brain modulation becomes more widespread, one question might need answering: is this legal? Performance-enhancing drugs aren’t, so why should performance-enhancing devices be?

“If you get to the point where you can start to shave seconds off [your] time,” Tyler says, “then I think there might be cause for concern. But we’re not there yet.”

Thync is neither a drug nor a medical device that would require FDA approval, but by modulating norepinephrine it can produce similar effects as banned doping agents. Beta blockers are on the World Anti-Doping Agency’s list of prohibited substances, and athletes such as North Korean Olympic pistol silver- and bronze-medalist Kim Jong-su have been caught using them to lower their heart rate, and reduce tremors and anxiety. These drugs work by blocking receptors for norepinephrine, whereas Thync’s calm vibe simply reduces the amount of the neurotransmitter, but the effect should be broadly the same.

But WADA bans drugs, not devices, so Thync and other wearables that might allow athletes to adjust the balance of hormones without resorting to chemicals aren’t prohibited. And even if they were, says Tyler, “you can’t test for what we do. It’s not in your blood or your urine.”