Back in 2013, Brazilian scientists showed that they could boost cycling performance by running a weak electric current through cyclists’ brains, using a technique called transcranial direct-current stimulation, or tDCS.
The finding, as you can imagine, opened a can of worms. It’s fascinating from a research perspective, because it tells us something about the nature of our limits. If tweaking our neurons enhances endurance, it suggests that even when we’re pushing “all out,” our muscles still have some reserve capacity. Further experiments with tDCS (notably from Lex Mauger’s group at the University of Kent) are already starting to shed new light on the interplay between brain and body.
The prospect of boosting athletic performance via brain stimulation is also, of course, alluring to athletes. Back in 2014, I visited Red Bull’s headquarters in America during a five-day research camp where they tested some of their elite cyclists and triathletes with and without tDCS—with, it has to be said, inconclusive results.
In truth, the picture isn’t a whole lot clearer now than it was in 2013. The initial results have yet to be fully duplicated, as far as I know. At a conference in March, Mauger presented some preliminary results once again showing an increase in cycling performance (with no change in heart rate or lactate levels) following tDCS. In contrast, at the American College of Sports Medicine annual meeting earlier this month, another Brazilian group presented data that failed to find any improvement in a repeated sprint task.
All of this brings me to the Golden State Warriors, American basketball team, and to the tDCS headphones that they may or may not be using in their quest to wrap up another title. The headphones are made by a company called Halo Neuroscience; the idea is that if you wear them for 20 minutes before a workout, you’ll put your brain in a state of plasticity that enables you to make greater gains during the workout.
It’s worth noting that there are striking similarities between the tDCS headphones and other, seemingly unrelated topics I’ve written about recently, like DNA testing to guide training and a cure for muscle cramps. In each case, fascinating but preliminary research has made the leap to consumer product, and in the process certain details get hidden away as proprietary information, and the prevailing standard of evidence shifts to case reports and non-peer-reviewed studies.
I understand why this happens, even if I wish for greater transparency and less hype. What I hope, when I write about these products, is to balance excitement about cool new ideas with context about how thin the evidence behind them is so far. Even if tDCS works, we’re a long way from knowing exactly how to use it, when to use it, or even which parts of the brain to use it on. But if it works at all, even if only under certain very restricted conditions, that’s still pretty amazing.