While it is just a couple of milliamps of positive electric current (about what a 9-volt battery produces), as an engineer who has had to worry about maximum electrical current tolerances for creating safe medical devices, I admit that the thought of zapping my brain using a headset initially made me feel uneasy. However, after speaking to Emily Hu, an elite powerlifter (not coincidentally, a triple world record holder in bench press in two weight classes), my skepticism gave way to my greater curiosity and I decided to zap my own brain.
Created by Halo Neuroscience, a Silicon Valley firm founded by Dr. Daniel Chao and Dr. Brett Wingeier, the Halo Sport uses a process called transcranial direct current stimulation (tDCS) to stimulate the brain. It sends a low level electric current of around 1.4 to 2.2 milliamps to a targeted region of the brain to excite the neurons, effectively “priming” them to be more likely to fire and create new neural pathways. This means that the brain temporarily becomes better at hard-coding what you are doing.
In effect, this is what the Halo Sport headset created by Halo Neuroscience is supposed to do. This headset stimulates the motor cortex, the part of the brain that controls movement, and primes the brain to get better faster at exercises in a workout, playing the piano, or any other activity that may require trained physical movements.
The brain’s role in exercise is more than just the mechanics involved in precise movement-related skills: it is also involved the mastery of muscle groups and muscle memory. 
Therefore, it is not about how big your muscles are, but how well you can use those muscles. Neuropriming therefore plays a role in accelerating gains in strength, endurance, and skill. In other terms, the technology temporarily increases the brain’s neuroplastic state, or state of “hyperplasticity.”
We had an opportunity to speak with Halo Neuroscience founder Dr. Chao and Kane Russell, Head of Marketing & Partnerships. We also interviewed world-class powerlifter Emily Hu and tested out the Halo Sport headset firsthand. Read on below…
Q&A With Halo Neuroscience
Alice Ferng, Medgadget: Is this device safe? And at which point in developing this product were you convinced that it was safe and that you were willing to put in on your own head to try?
Dr. Daniel Chao, Halo Neuroscience: Yes, the type of stimulation used in Halo Sport, known as transcranial direct current stimulation or tDCS, is safe. tDCS is backed up by over 15 years of research – 3,000 peer-reviewed articles covering over 60,000 sessions all speak to the excellent safety profile of tDCS. We’ve also tested Halo Sport in-house on over 1,400 healthy volunteers, and have encountered no safety issues. In addition to the fundamental safety of tDCS stimulation, my co-founder and Halo CTO, Dr. Brett Wingeier, and I have built safety into the product at every step, including medical-grade safety and human factors engineering based on international standard ISO 14971, and recently we’ve collaborated with academic and industry partners to define additional engineering standards for consumer neurotech devices.
You can learn more about the safety of Halo Sport from the Science section of our website at haloneuro.com/science#safety.
Medgadget: Is there a maximum number of times a day/week that the Halo can be used for? Are there any contraindications for using of the Halo?
Dr. Chao: We recommend a max of one Halo Sport stimulation per day. Usage beyond this level will result in diminishing returns, because the brain not only needs active training reps to encode repetitions, but also rest time to consolidate learning. Athletes understand this dynamic of course, given the analogous relationship between training the brain and the muscles. In both cases, rest and recovery are as important for improvement as activity.
In addition, Halo Sport works best when used in conjunction with what many in the sports science field refer to as “deep practice,” or days when repetitions are designed for improvement, not rest. As a result, Halo Sport athletes use the product every day they’re focused on “deep practice,” or roughly 3-5 times per week.
Regarding contraindications, most healthy athletes over 18 years old can use Halo Sport, although individuals with medical or neurological problems should of course consult their doctor before training with Halo.
Medgadget: Is there such a thing as overstimulating and overtraining the brain with tDCS?
Dr. Chao: Research at Halo and other institutions has not suggested any such adverse effects. That said, anything related to the brain or body eventually reaches a point of diminishing returns, were more is counterproductive. Our customers limit their usage to once per day according to the reasons described above.
Medgadget: Does changing the amplitude setting on the headset change the effectiveness of Halo Sport? What is the science behind that?
Dr. Chao: Changing the amplitude does change the effectiveness. With training reps being equal, a higher intensity level will provide more benefit. That said, we designed the entire amplitude range to be both safe and effective. We recommend choosing an amplitude setting that allows users to feel the stimulation, but one that is comfortable so they can focus on the high quality repetitions during their workout.
Medgadget: What’s the next step for this product? Are there additional methods of tDCS that Halo Neuroscience plans to employ in future headsets, or other techniques?
Dr. Chao: On January 30, 2018, Halo announced a Series B financing that will help us create new products with the ability to help people maximize their performance.
Medgadget: What are the current state of regulations for non-invasive neurostimulation devices and what are the difficulties in getting approval for devices like this?
Dr. Chao: The underlying technology in Halo Sport is known to the FDA and other regulatory bodies. Halo Sport is considered a general wellness device, like your Fitbit or your gym equipment, which does not require clearance or approval when used by healthy people for performance applications such as athletic training or musical practice. We do look forward to medical applications, at which point we’ll go through processes similar to what we did at our last company, Neuropace, where we secured FDA approval for an implantable neurostimulation device to treat epilepsy.
Medgadget: What is your background, and what got you interested in joining Halo Neuroscience?
Kane Russell, Halo Neuroscience: In 2013, I had an opportunity to be an early tester of Halo Sport in a research trial. That experience piqued my interest in the company and I remained in contact with Dr. Daniel Chao, CEO, until 2016 when I was brought onboard to bring the product to market. I was excited about Halo Neuroscience from the beginning due to the scientific connection with sports performance, cognition, and foreign language, which are topics of personal interest.
Medgadget: What are your top customer demographics? Was this different from the initial target market?
Mr. Russell: Our top customer demographics are lifelong athletes who continue to look for the competitive edge bringing them to the next level of strength, speed, performance and competition. For us, that means people in the realms of running, cycling, CrossFit, and weightlifting. Musicians are also a big focus for Halo Sport, as those looking to improve and master their instrument also rely on muscle memory.
Medgadget: Were there any concerns about the barrier to entry for a neurostimulatory device like this? At what point did the Halo Sport headset start to catch on with different groups? Was there a particular event or turning point from the marketing point of view?
Mr. Russell: Halo Sport was originally designed with athletes in mind, but when you think about what goes into “movement-based training” — i.e. repetitive movement to increase precision, timing, accuracy, and strength, musicians can benefit just as much as athletes. One turning point that comes to mind was when pianist Mario Marzo conducted his own study of Halo Sport and its effect on learning music. Mario chose two new, equally difficult piano compositions, and set out to learn one with the help of Halo Sport and one without. You can see his “experiment” here.
Medgadget: What’s next? Are there plans to create other similar devices? What about plans to partner with other companies? What types of partnerships or collaborations is Halo Neuro interested in?
Mr. Russell: As you know, Halo has just announced a new financing for Series B in order to create new products with the ability to help more people maximize their performance January of this year. Halo has worked with teams and athletes in the Olympics, military, MLB, NBA, and NFL, as well as thousands of elite endurance and strength athletes around the world. We’re interested in partnering with organizations who are looking to understand how brain-based training can open up their world of performance.
Testimonial From A World-Class Athlete
Medgadget: What got you into the sport of powerlifting, and why?
Emily Hu, Elite Powerlifter: I really wanted to try something new, and while I have been active and fit my whole life, I had never been strong. Growing up as a gymnast and martial artist, I never felt that I had any strength or power. It was to the extent that I actually quit gymnastics because I wasn’t strong enough to do any of the more advanced techniques on the bar and that prevented me from moving up to the next level.
Medgadget: How long into the powerlifting journey was it before you started using Halo Sport? And from there, how often do you use it? How often do you lift per week?
Ms. Hu: I was a powerlifter for about 4 years before finding Halo Sport. Even as a non-beginner lifter, I found the Halo could still help me learn better technique and improve in a sport in which I was already competing at a high level. In the beginning, I used it with every workout. I don’t use it as often now, but I still like to use it as often as I can. I try to lift most days of the week.
Medgadget: How long did it take before effects of the device kicked-in and you started noticing anything different?
Ms. Hu: I’d say pretty instantly, within a few days. You feel a little different the first work out, and then it adds up over time.
Medgadget: How did you feel Halo Sport improved your lifting or what kind of gains did you have in weight or performance?
Ms. Hu: It was more like I could concentrate on maintaining better form, so getting stronger wasn’t the primary effect but a secondary. The better form just let me lift harder, more efficiently, and be able to do more repetitions.
Medgadget: Do you see any use-to-use variations – meaning from one lifting session to the next, do you feel like using the headset affects your workout differently? Is it just as effective each time?
Ms. Hu: I find it to be just as effective every time.
Medgadget: Have you tried the headset for something other than lifting?
Ms. Hu: Not yet, but I intend to try using it to get better at partner dancing (i.e. Salsa, Tango).
Medgadget: Would you recommend using this headset to people? What populations of people would you most highly recommend Halo Sport to?
Ms. Hu: Yes, definitely. The headset is pretty beneficial to anyone who is trying to improve a physical skill, whether it be neophyte athletes or intermediate pianist.
Testing Halo Sport Myself
The Halo Sport headset is designed to be used 20 minutes before a workout, while warming up, with the neuroplastic state expected to last for about an hour after neuropriming. Using a Bluetooth connection, the headset is connected to an app, available on iOS or Android.
The primers are electrodes that are made of soft foam nibs that sit comfortably on the head, and the primers are wetted with water before wearing them on your head to provide ample conductivity. The app on your phone will help you determine whether or not conductivity between the primers and your scalp is sufficient for neuropriming. Setting the headset up initially can be tricky in terms of positioning the primers with sufficient contact with your head, especially if you have long-hair or lots of hair, but once you figure it out it is pretty simple. If there is a reduced absorbency and reduced contact with the head, primers can be “recharged” in a saline solution also provided with the headset.
Once the headset has been connected properly, the mobile app will prompt you for how you want to neuroprime. This can be to train full body movements (Legs, Core, & Arms), or finer hand movements, with a left- or right-sided emphasis.
Some pro tips: 1) Make sure the primers are snapped firmly in place on the headset if you remove them to wet, 2) Make sure the primers are wetted sufficiently: 20+ seconds under the tap, or submerging the tips into water, 3) Do not comb the headset into position from the front of your head or else it will dry out the primers, 4) If you have long hair or lots of hair, you may need to wiggle the primers into place through your hair to ensure contact with the scalp, 5) Make sure the headset is snug against your scalp by pressing down on the sides and top of the headset, and 6) Re-wet primer tips or primer if having issues with connectivity still after all of the above.
It goes without saying that each individual’s experience will be different, and the effects will be similarly different and dependent on how the headset is utilized. For me, when the device is on (I leave it at its recommended medium level), I feel a tingling sensation on my scalp that slowly ramps up over time, and towards the end of the 20 minutes, my scalp starts to feel itchier and more sensitive, but I stick to it and complete the session.
From the very first time I used this headset, to the many times I used it in the following weeks while doing CrossFit or weightlifting, I did notice an effect. The best way I can describe how it felt is akin to a caffeine buzz or high, when you have had just the right amount of caffeine and you feel like you can focus well and conquer the world. Or like a runner’s high or workout high, where you feel dialed in to the task at hand and feel like you can do anything, though this is again related to focus. For me, using Halo Sport created that higher level of focus without having to consume caffeine or supplements, wherein I was able to be more mindful and aware of my body as I was training. In terms of weightlifting, the increased focus allowed me to really work on my form and movements, and over the course of 7-8 weeks, I saw as much as 50 lb increases on my lifts. Though I attribute these gains, in part, to my amazing coaches who called out nuances in my form to improve on, without which I would not have known how to apply that extra feeling of greater focus from using the headset. Given the trajectory of the months prior to using Neuro Sport, with the training I was doing, I had similarly made up to 50 lb gains in the prior weeks. That is to say, I think I would’ve continued to see training gains regardless.
To the skeptic: I think it would be misleading to claim that an external device would boast great improvements in any skill or task without intentful practice. For those who are athletes, whether in sports or intellectual endeavors, we know there to be good training days and bad training days. On those good training days where you are able to focus on all the minor adjustments and improvements of technique and skill, you expect to see faster improvements than on bad days. Halo Sport is something that on some days I felt helped shortcut the path to feeling like I was able to have better focus. However, I did not feel the same magnitude of effect at every single training session. There were bad days, where I was distracted by something else that ultimately led my lack of focus to prevail despite neuropriming. Thus, as expected, gains were not noticeable during those times, and I might have even felt like I did worse than usual.
To expect large gains without putting in the work would be unreasonable, and so I think to newer adopters of this type of technology, it would behoove to put in their due diligence in training and practice as they normally world. Being a scientist, I always have a healthy dose of skepticism and ultimately expect many experiments to result in failures, though I have learned over time to simply keep an open mind and be realistic. I really did not know what to expect when I first put on Halo Sport, so being able to isolate the personal effect of the headset on myself as something attuned to a caffeine-high-induced-productive-state made me curious to apply it in another context to further investigate the effects of neuropriming on myself.
I chose to neuroprime myself prior to some keyboard playing sessions. As a classically trained pianist who played through college in the music department, this application of the technology seemed to be the right fit, as I have spent countless thousands of hours on my fine-motor skills already. Often spending multiple hours on playing the same few measures of music over and over again to refine specific technical skills back in the day, this type of mind-numbing practice is what serious musicians and athletes are used to. So in this context, I would not expect that I would see any gains in my technical skills, as they have already been honed and trained, and therefore this would provide me a perfect platform to analyze the headset on myself further.
After 3 weeks of sessions, I did not see any quantifiable skill gains when neuropriming prior to my music sessions on the keyboard. Perhaps this was due to several factors, a major one being that I was not trying to memorize dozens of pages of a concerto to be played in front of a panel of judges. Another factor would be that it was not like lifting, where I had a self-identified goal or expected outcome. I will say, however, that that feeling of inspiration when it just hits you and causes you to end up playing and improvising for hours on end did happen a few times. To that respect, I do believe that the “primed” state aided in making my mind feel more focused and clear, which helped me attain that state of mind.
In conclusion, I would advise other adopters to just keep in mind that the effects may not be what you expected… so keep an open mind! The gains may not be immediately noticeable, but they may come in unexpected ways over time. Just as in weight loss, there’s no magical solution without putting in the work and mindfully approaching the problem.
