The future of Fitbit: New sensors, serious health tracking and more

We ask Fitbit's head of research about life after the Ionic launch
Lifestyle photo of Ionic Indoor Young Adult Female
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The next few days, it's fair to say, are going to be a pretty big deal for the hopeful startup-turned-billion-dollar company we all know as Fitbit. 2017 marks 10 years since co-founders James Park and Eric Friedman saw the potential of putting sensors into wearable devices and on 1 October it prepares to break into a new category with the Ionic smartwatch. This is arguably its most important launch to date because it will shape what comes next for Fitbit.

Shelten Yuen leads research and development at Fitbit building the sensors that unlock staple fitness tracking features like sleep monitoring and the ones that will enable Fitbit's smartwatch to help detect disorders like sleep apnea. Yuen, whose previously worked in missile defence and robotics before joining Park and Friedman says his background does ties in with what he has been working on at Fitbit for the past eight years. "It's about taking sensory data and making sense of it. That's still what I do here at Fitbit." he said.

Wareable verdict: Fitbit Ionic in-depth review

We've already spoken a lot about Fitbit's first smartwatch. We've worn it, tested it and seen what it is capable of, but what we really want to know is, what happens next? What data will be unlocked and which sensors will make it all possible? While we wouldn't expect Fitbit to give away all of its big secrets, we did want to get a better picture of what could be on the horizon.

Back to the future

The future of Fitbit: New sensors, serious health tracking and more

Before looking forward, we asked Yuen to look back to those early years to find out whether James, Eric and the team really believed they would be where they are now 10 years down the line with a family of wearables that are worn by millions of people across the world.

"When I met James and Eric and we tried to think about what Fitbit could be, we envisioned a world where these sensors would be ubiquitous and all over the place", he said. "It was about using sensors throughout your life and to really help motivate people to reach peak fitness or to reduce the chances of diseases. Thinking practically, I didn't think Fitbit would be a household name and just all over the world as it is today. It's been a phenomenal ride and really speaks of the right timing and that Fitbit basically made this space."

I didn't think Fitbit would be a household name and just all over the world as it is today

Yuen was pivotal in the development of Fitbit's PurePulse heart rate sensor technology, which began back in 2011 taping parts together to see if the concept of sensors measuring from the arm or the wrist would even work. Now it features in the Charge 2, Alta HR and of course the Ionic. This is the same PurePulse technology Fitbit hopes will unlock the ability to detect atrial fibrillation, a condition tied to heart failure. In those early years of development even Yuen was sceptical whether PurePulse could actually work. "An all day heart rate monitor was unheard of the time," he told us. "Even though my team was tasked with building it, I was deeply sceptical of it until we started to collect the data and that data proved we could make it.

Read next: Best Fitbit devices 2020

"The idea that we can have a heart rate sensor that is so much smaller like we have inside the Alta HR and still have the same battery life is sort of mind-blowing to me. I don't think in the early years of Fitbit I could have predicted that we would have the kind of sensors like we do in the Ionic that has the potential to predict sleep apnea. Three years ago we did, but if you had mentioned that to people three years ago they would have laughed."

Moving beyond fitness

The future of Fitbit: New sensors, serious health tracking and more

We've talked about how the Ionic represents a pivotal moment for Fitbit as a company and that largely lies with its decision to get serious about health tracking. Its trackers have already been used in over 400 clinical papers but with the SpO2 sensor that currently lies dormant inside of the Ionic able to unlock health monitoring capabilities, Fitbit is no longer just about getting you to move more. It's got bigger plans.

Read this: Sleep apnea explained: The disorder Fitbit is trying to crack

"I think even when we started looking at our PurePulse technology we started to sketch out what else you could get from that", Yuen explained. "Even in the early stages we were thinking not only about heart rate during exercise but also the public health side and vital signs monitoring. Resting heart rate is one of them. VO2 Max was another thing we were thinking of. Looking at heart rate variability was another thing as well.

If you've thought of a metric related to heart rate, chances are we are looking at it or have looked at it in the past

When you have an optical sensor on your wrist it's an excellent platform to work with. There are other wavelengths that we have been considering like the SpO2 sensor to detect sleep apnea."

Tapping into the heart remains a priority for Fitbit, whether it's for producing VO2 Max readings for aspiring runners or using heart rate variability to help your relax with guided breathing. But are there any more heart rate metrics that Fitbit have yet to unlock?

"I would say if you've thought of a metric related to heart rate, chances are we are looking at it or have looked at it in the past," Yuen said. "We want to try and release features that are really compelling and really work for people out in the field. Another thing we want to do is to make sure we don't overload the product so it becomes too confusing or too expensive.

"It's been challenging to make heart rate variability a consumer-centric metric that is meaningful to people because it can vary for a lot of reasons. Caffeine intake, circadian rhythms - there's a lot that can influence it. Another one is heart rate recovery, which is seen as a good metric for clinical populations to determine if you are at risk of heart rate failure. The extension of this to the fitness space hasn't really been that clear."

AI, hydration and the rise of neuroscience

The future of Fitbit: New sensors, serious health tracking and more

What a Fitbit device will look like in 10 years time, where it will be worn and the technology inside of it is something we are sure the company already has clear ideas about. While it feels like optical sensors are in it for the long run, it's about what other data can be unlocked with them strapped to your body. One of those things could be hydration, something that we've seen being explored by a number of startups and could have benefits in both the fitness and health realms.

"From a sensor perspective hydration is a really big deal", Yuen said. "On Fitbit we've had water logging since the beginning. I do think that's one of the areas that is ripe for innovation because it's challenging to log your water or your food. Within my team we have explored the world of hydration and we think there is a lot of opportunity around this."

Another trend we are beginning to see in the wearable space is the use of neuroscience and tapping into the brain to improve athletic performance or even just to help you de-stress. Fitbit has neuroscientists on its research and development team and Yuen believes it's an area that shows a lot of promise.

The future of Fitbit: New sensors, serious health tracking and more

Thync (above) is one of the startups exploring the neuroscience wearables

"A lot of sensors in this neuroscience space on the engineering front has been on interfaces and being able to control things," he explained. "That's been very challenging on that front and there needs to be more investigation on that. I think in terms of therapeutic devices, that's pretty interesting. I don't think there's enough evidence for us to roll something out like that and get that out on a broad scale. But it's an interesting space and something that we are looking into. I think it is interesting that people are willing to inject currents into their heads. It's been interesting in the wearable space to see just how much it's been embraced."

There's no escaping AI. It's everywhere and the idea of using computerised tools and machine learning to develop features is something that Fitbit believes in too, and something it strives to improve going forward to provide better insights and more actionable data. It's that data that Yuen believes is crucial to making artificial intelligence really work for Fitbit users now and in the future.

"I've had this experience when maybe you're talking to a loved on and they just look at your and ask if you are okay," he said. "You may not have noticed something is wrong with you, but maybe you're stressed or sick. That comes from a very deep relationships that we have, essentially a parent has collected data over many years.

"Fitbit is poised with all the data we have collected over the years we are able to harness that data to effectively make Fitbit your ultimate health and fitness buddy. I think the way we get there is by using machine learning so that Fitbit can say your sleep is bad or it has been bad over three months. The potential is huge."

Moving away from the wrist

The future of Fitbit: New sensors, serious health tracking and more

If you discount Fitbit's smart scale, then Fitbit's Flyer headphones represent the first time it has made a device for another part of the body. The in-ears don't track biometric data or offer anything other than a way to listen to the music packed onto your Ionic smartwatch, or benefit from the audio coaching that will be added to Fitbit's Coach training platform.

There remains plenty of healthy debate as to whether the wrist is the best place to draw biometric information. So could the Flyer indicate an openness that one day we will be tracking health and fitness metrics on a Fitbit from another part of the body?

"Speaking from my own perspective, we look at all sorts of form factors whether they are on your head, in your ears or other places", Yuen said. "There are other sensor opportunities there but you don't necessarily want to cram a whole load of sensors into your ear because it can drive up the price of the device like that.

"They are so small, and have to be lightweight and can only manage a few hours of battery life. Also, you are not going to want to wear those to track your sleep. You may not wear earphones to sleep. We think of health and fitness all of the time and earphones don't really allow that for everyone."

Fitbit at 20

In another 10 years time Yuen wants Fitbit to be your personal health and fitness assistant, a hub that's always there with you with years of data, and he believes they will be there before they hit that 20th year. He also believes that Fitbit will provide more reasons not to take your Fitbit off whether that's through new smartwatch or fitness tracking features. But there's more that this billion dollar company wants to achieve, some of which we are already seeing the early signs of.

"The integration into the health care system and just how your information is fused with the more medical side, that will be a natural extension of what we do," Yuen told us. "There's growing evidence in clinical circles and academic research circles that using wearables like Fitbit is handy for medical investigations and changing the standard of care. Looking at things like whether you can you mitigate the recurrence of breast cancer in certain populations. Can you predict when people should leave the hospital after operations. There's no real precedent for that and I think we have a great opportunity here to try and do something really great."

How we test

Michael Sawh


Michael Sawh has been covering the wearable tech industry since the very first Fitbit landed back in 2011. Previously the resident wearable tech expert at Trusted Reviews, he also marshaled the features section of

He also regularly contributed to T3 magazine when they needed someone to talk about fitness trackers, running watches, headphones, tablets, and phones.

Michael writes for GQ, Wired, Coach Mag, Metro, MSN, BBC Focus, Stuff, TechRadar and has made several appearances on the BBC Travel Show to talk all things tech. 

Michael is a lover of all things sports and fitness-tech related, clocking up over 15 marathons and has put in serious hours in the pool all in the name of testing every fitness wearable going. Expect to see him with a minimum of two wearables at any given time.

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