Make way for another wearable. Launching sign-ups for its alpha program on stage today, here at TechCrunch Disrupt SF, is a startup called Humon — which is building a real-time lactic acid threshold monitor designed for endurance athletes to help them tailor training to their personal limits.
Two of the co-founders behind Humon met at MIT and MIT Sloan, where the team has also this year been through a summer accelerator program — taking in a $20,000 equity-free grant from MIT to help with product development. They’ve otherwise been bootstrapping development thus far.
So what exactly is Humon? it’s a wearable, targeted at endurance athletes such as marathon runners, which attaches to the working muscle — so it’s worn on the quad with a strap around the leg to hold it in place — where it monitors how oxygenated the runner’s blood is by shining a light into the skin and analyzing changes.
“We’ve been through six iterations of our prototype,” says co-founder Alessandro Babini, discussing the current stage of development. “We have something that’s completely wearable, that measures the way your muscles use oxygen in real time… so completely optically — real-time, no blood. That’s something you cannot do today. And now we’re feeding this data through our algorithms to identify lactic acid threshold.”
The lactic acid threshold refers to the point when levels of lactate created in the body during exercise step up significantly, rising faster than the body is able to clear. Athletes typically try to train within their lactic acid threshold — to avoid the risk of exhausting themselves by overtraining. But the threshold can shift, depending on their level of fitness, so knowing how hard they can train at a given point can be difficult to judge.
“We give the recommendation to the athletes so you can get to, scientifically, the maximum possible performance your body can sustain,” says Babini of the product’s aim. “When you reach a certain level [of exercise] lactic acid starts accumulating in your blood… And we map the evolution of the threshold also so… we remove the risk of hitting the wall which is one of their biggest fears.”
The wearable uses an optical sensor to analyze changes to the color of the blood in the leg which are representative of how oxygenated the blood is — and from that the team infers lactic acid levels. “We can infer from that exactly what kind of change in that optical properties is actually due to the change in color of the blood within the  muscle. And so from that we know exactly how much oxygen is being used in your muscle,” he says.
“Lactic acid is created as a result of exercising with this continued oxygen deficit… By kind of bookkeeping this consumption of oxygen over time we can tell how much lactic acid has been accumulating.”
To be clear, Humon’s optical approach is not capable of determining exact lactic acid concentrations in the athlete’s blood. Rather it’s about identifying when an athlete can safely push themselves a bit harder.
“We are not at a point where we are attempting to determine lactic acid levels in terms of concentration (i.e. mmol/L),” adds Babini. “We have interviewed upwards of 200 endurance athletes, and the vast majority of them do not value this information, as it still requires them to understand what this values means for them. What is most important to the athletes is that we let them know how hard they are pushing themselves relative to their threshold. This is the information that they need to train.
“For example, they may perform an interval workouts at 110% of their threshold, or long-sessions at 60% of their threshold. By looking directly at the way the muscle is using oxygen, we believe that we can get an even better insight into the athletes’ level of effort versus the limits of their body.”
The idea to focus on a wearable that can identify the lactic acid threshold came after the team did market research into multiple wearable markets — and found the clearest demand from athletes.
“We looked into more than eight different markets — from ICU patients to military, elderly, children, athletes. And when we got to the athletic market, we asked that simple question: what do you need to know about your body right now, that you don’t and that would change your life? And every single one of the athletes responded ‘lactic acid’,” says Babini.
He claims there’s currently no way for athletes to measure lactic acid in real-time — saying instead they typically train on a treadmill and have pinpricks of blood taken several times in order to manually plot a lactic acid curve. So, compared to that cumbersome process, a real-time non-invasive lactic acid measure seems like a step change.
That said, Humon is not actually first to market here. BSXInsight crowdfunded an optical lactic acid threshold monitor which is worn on the athlete’s calf last year. Others have also tried sweat monitoring wearables as a way to quantify lactic acid, so there are other non-invasive approaches out there, although Humon (as you’d expect) argues its tech is superior — claiming it yields “the most direct and real-time data”. And that accuracy is better than measurements done through sweat.
Asked specifically how Humon compares to BSXInsight’s wearable, Babini claims it’s not a like for like product. Rather, he says the latter’s wearable is designed to give the athlete their lactic acid curve four times a year — and requires “additional inputs such as, heart rate, speed and cadence data to work” — instead of giving daily or real-time feedback, as the team intends with Humon.
“Athletes want to a solution that they can wear daily during training, outdoor or indoors and that does not need extensive calibration. We’ve bought [BSXInsight’s wearable], tested it, talked to their team and do not think they have a compelling product that solves our target market’s problem,” he adds.
Humon’s wearable is being designed to work in conjunction with an app, so athletes can view their data in real-time if they run with their phone, or after the race if they don’t. It will also be able to sync data with existing smartwatches, such as those made by Garmin. And has an internal battery plus memory to store data for syncing later if the athlete runs without a Bluetooth phone or watch.
Weight-wise they’re aiming for it to be around 40g or less and about the size of a heart rate monitor, according to Babini. The price-point they’re aiming for is $300, although they are also planning a subscription model for those wanting to pay for extra analytics.
“Because we measure the way your muscles use oxygen we really measure the true power that’s in your muscles,” says Babini of the subscription plan. “We can learn a lot about how hard your muscles are working. And how well they recover. So that recovery piece is also extremely important — and we’re thinking of charging the extra subscription to get this information about muscle recovery.”
How big does Humon reckon the market for such a specialist wearable is? Babini says the  “extreme or semi-professional” endurance athletes segment is a $900 million market in the U.S. — “and is expected to grow extremely fast over the next three years”. The team’s longer term goal is to broaden its target from focusing on the pro segment to move into the amateur fitness space too. “If you look at the sports wearable market, last year it was $2 billion, and it’s expected to grow 3-fold in the next three years, so it’s one of the fastest growing markets,” he adds.
The team is now looking to raise $1 million from investors to fund the next push of product development — and ultimately to get the wearable to the market next year. “We think we’re on track to ship something next summer, so in a year from now,” adds Babini.
Humon’s alpha program is initially available to testers in the Boston area, but the team says it will be opened up countrywide soon.
Q&A
Q: What’s the pricing?A: It will be priced at around $300 – you could compare that to a high end Fitbit because we believe that this tech is a game changer, and initially will be beneficial for what we call the extreme semi pro level but can be extremely useful for the more amateur market. And we want to make it available to everyone
Q: Is that a production ready unit? Or is that something you 3D printed. It looks like you started last month so you made some tremendous engineering progress if that’s real.A: We started last month. That’s our incorporation date. This is what our alpha versions will look like. Everything fits inside, you gather some data. This is what you can try out if you sign up on our website
Q: How many sensors are there?A: There’s a couple of LEDs and detectors in different positions. That’s kind of where our IP lies.
Q: What ‘s the volume manufacture price?A: Low volume $65, high volume $20
Q: How important is it in terms of where it’s positioned on you to be accurate?A: If I give it to you and I tell you it needs to be on the thigh. If you put it here, here, here it’s going to work. The positioning is not very important it I just needs to be in this area. And we get reliable data anywhere on the quad.
Q: For your target market what percentage of those people wear heart rate monitors when they train?A: Roughly 50 to 60 per cent. But the point I was saying is that heart rate is the status quo today because it’s kind of the only indicator you can measure at my hand here and look at my watch. And that’s because this measurement was so easy to make that the heart rate became what it is today. But essentially heart rate data is extremely hard to leverage for performance [needs]. Nearly impossible. Because on the same day, the same weather, if you do the same race your heart rate is going to spike at completely different levels depending on how much coffee you had, or how much sleep you had… The point being heart rate is extremely difficult to use in order to leverage performance during a rate or a workout.
Q: You’re measuring oxygenation of blood? Are you measuring lactic acid somehow? You kept talking about lactic acid…A: We’re measuring the way your muscles use oxygen and it’s the use of your muscles in a deficit of oxygen that leads to that production of lactic acid. So that’s exactly by bookkeeping that consumption of oxygen we know how much lactic acid you’ve accumulated. But in addition to that there’s a lot of benefits by the fact that we’re measuring something upstream of the production of lactic acid in that we know that you will accumulate it to an unacceptable level before it happens
Q: How much testing can be done to calibrate your approach of this bookkeeping approach you’re talking about to the actual measurement of lactic acid in people?A: So every test we’ve done in house we’ve correlated with actual invasive blood test measuring lactic acid. This measurement of muscle oxygenation… we’re doing clinical trials in November to completely validate it. But the internal validation we have makes us believe it’s very accurate.
Q: You guys must have scars from all the testing then…A: Yeah we do, actually. We’ve had every single finger pricked at least 100 times.
Q: What does go to market look like for you guys when you’re ready for a major release?A: We’re extremely lucky going into this market because if you take runners, triathletes and cyclists it’s one of the strongest communities in the U.S. They meet up every weekend, all over the country, and so it’s something also we’ve seen during our primary market research where we talked to triathletes, runners and cyclists and we would get 5 to 10 referrals every single time.
Initially we want to sell direct to these guys, go to them and leverage the word of mouth – hopefully make a device that will be a game-changer for them. Obviously over the longer term it’s going to go through a strong reseller network to make this available as broadly as possible.
Q: A few years down the road are you guys are going to be building a lot of devices? Or are you going to be a single device company? How do you think about yourselves?A: When we started this company we sat down and thought where is the world doing to be in 10 years. And in our mind there’s no doubt that we’ll all be wearing some piece of technology that will non-invasively monitor our body parameters, allowing us to be more healthy and in better shape. Now today this is steps, sleep time, pace. When we think of this world in the future it will be stuff like vitamin levels, hormone levels and lactic acid. So this is the vision we have for the company.
Q: What is the cost of manufacturing one of these?A: So low level $65, high level $20.
Q: Do you have a sense for how well it works in the water? You talked about triathletes and you had a picture of somebody swimming.A: Underwater it’s not meant to work during the underwater part of the triathlon. It is completely sweat proof. But the data you get underwater is not accurate enough to be leverageable. So we’re not going to pretend we can make it work underwater.
Q: Where you pointed on your thigh is kind of a provocative concept in that I put a lot of other consumer electronics in the same region – have you guys got the game down what this looks like a year out, five years out? Is there anybody else that’s a larger, better funded, more established computer electronics designer that might actually compete with you for that sort of position on the thigh? Who could add that to their feature-set?A: We hope to be that better-funded company down the line. But if when you’re talking about the big companies today, the Apples and Googles of the world, the reason we think they won’t compete with us right now is because they’re going for the more lifestyle market of wearables. We provide essential insights; we’re not making a piece of jewelry that can give you steps. Or kind of is cool to wear. We’re giving this to athletes because they need the data to achieve their goal which is improve their performance and win the race.
