Your Apple Watch May Know More About Your Health Than Your Doctor

IT’S EARLY ON a sparkling blue-sky fall day in Cupertino, California, and Apple Park is humming. Employees stroll into the gigantic glass-and-aluminum ring, while on the perimeter path a running group gathers for some pre-work miles, other employees zip by on e-bikes, wind rustles through the trees, and birds chirp and warble. Steve Jobs famously likened the ring to a spaceship, and going inside it feels like you’re stepping into a gleaming future, where you’re compelled to imagine a better version of yourself.

I’m in a wood-paneled room in the mothership to talk to Jay Blahnik, vice president of fitness technologies, and Sumbul Desai, MD, vice president of health. I want to explore how Apple’s journey in the fitness and health space has evolved and, more specifically, examine how wearable technology can empower people to live fitter, healthier, happier lives. It’s been a decade since the Apple Watch was launched in 2015 as a souped-up activity-tracking fitness device that could do more than just log steps.

Back then, MH went behind the scenes at Apple’s secret fitness lab to learn about the rigorous testing and science that inform the watch’s algorithms. Blahnik told us how “our lab has collected more data on activity and exercise than any other human performance study in history.” He explained the core feature, the three colored rings (Move, Exercise, and Stand), how the watch nudges you to hit daily targets for each (“giving you three ways to win!”), and how closing your rings every day is a way for you and friends connected in your exercise circle to be more engaged with your fitness.

Although the watch has evolved, Blahnik hasn’t changed much: He’s super energetic, bright- and blue-eyed with sandy hair, and he’s still passionate about closing his rings. When asked what he feels is the greatest impact of the Apple Watch in the past 10 years, he says, “We’ve been very pleased with the fact that the rings remain sticky 10 years later for pro users, enthusiasts, and beginners. The idea that a huge group of people, a massive audience, now has more sense of an active day versus an inactive day, or they know ‘I’ve just been sitting too much,’ understanding that they’re making progress and they can do better than they did before. The rings represent that for us.”

That massive audience Blahnik’s talking about, people who wear an Apple Watch, is estimated to be over 30 million Americans, and more than double that globally. “We’ve learned different things motivate different people,” says Blahnik, who has been working at Apple since 2013, two years prior to the watch launch. Before that, he was a fitness trainer and consultant for Nike, Bosu, Equinox, and other brands. “Every time we launch a new feature, for every person that loves the sparkly rings, there’s somebody else that wants to know their vertical oscillation when they run,” he says. “Then there’s another person who doesn’t even know what that is. The fact that there’s so much opportunity to motivate people where they’re at, and that these fitness features have been able to inspire so many great health features—I’ve been amazed at seeing how the simplest things can go a really long way and put someone on a trajectory that at the end of their life, it could add five or 10 years if you’re more active, if you’re sitting less, you’re more mobile, you’re more social. It’s just delightful that the watch has been able to do that.”

I also asked Dr. Desai the same question about the greatest impact of the watch, and she responded with no hesitation. “The life-saving impact—we hear from people every day whose lives have been saved by the watch,” she says, recounting how people have told her they were saved by an ECG alert, the A-fib feature, an elevated heart rate warning, or a fall alert. “It’s incredibly profound. It’s why we do this, why we work in health, to help people—and the fact that we’re doing it at the scale that we are doing is profound.”

While the rings and the heart rate monitoring remain constants, the Apple Watch has added significant fitness and health features almost annually for a decade: the Breathe app in 2016, heart rate variability and VO2 max in 2017, fall detection and the FDA-approved ECG app in 2018, sleep tracking in 2020, the Mindfulness app in 2021, A-fib history and sleep stages in 2022, and an FDA-approved sleep apnea notification, the Vitals app, and Training Load in 2024 with Apple Watch 10. Wear your Apple Watch regularly and it will gather a deep and wide variety of information, giving you critical insights into your health and fitness that can help you progress and, if necessary, inform your health-care provider’s decision-making.

Over the past decade, there’s been a growing consensus among doctors about the critical importance of fitness for increasing health span (the part of your life when you’re active and healthy) as well as lifespan—a consensus that the pandemic accelerated. As an example, Blahnik points to VO2 max, which is a measure of your cardiac capacity. “Our initial spark was people wanted to know how fit they were and if their fitness was tracking up or down,” he says. “What was driven as a fitness feature ends up being a really great preventive health feature.” That’s because, as Dr. Desai explains, VO2 max is an amazing indicator of overall health and mortality risk. As digital health-tracking technology evolved rapidly—in what some researchers call a democratization of data—more people started paying closer attention to their fitness, and they wanted tools to help them know their bodies better, in ways beyond those imagined by the pioneers of the “quantified self” movement of the early 2000s. Concurrently, doctors and professors like Peter Attia, MD, best-selling author of Outlive: The Science and Art of Longevity, and Andrew Huberman, PhD, creator of the popular Huberman Lab podcast, have grown large audiences giving people more and better information so they can take charge of their health, ushering in a new era of patient empowerment.

It’s an area where Dr. Desai sees Apple playing a powerful role. She mirrors Blahnik’s high energy and emphatic gesticulation, has been at Apple since 2017, and previously focused on the intersection of technology and health as a professor at Stanford University. She says Apple is very focused on how it can proactively educate people about their health so they can catch a potential problem before it arises. “Prevention’s one of these things that we are all taught in medical school as being critical,” she says. “But the way the many health systems in the Western world are set up, you’re only focusing on people when they’re sick. We feel like that’s a big mess. If we could walk away with anything, if we could say, ‘Hey, we made a dent in preventative health to be able to drive people to know about things in their health earlier and actually avoid further complications,’ that’s truly an impact that is bigger than what we could have ever imagined.”

She adds that the world has “falsely created a separation between fitness and health. But if you look at physiology, it’s all one. There is a synergy between the two worlds, and that’s what’s great about working so closely with Jay [Blahnik].” Synergy is one of those words that’s bandied about so much, it’s easy to forget what it actually means. The dictionary reminds us that synergy is the interaction of a group of things working together to produce an effect greater than they could achieve by working separately. That synergy can help us live healthier, more active lives—and informs the evolution of the Apple Watch. Surprisingly, the synergistic opportunity at Apple almost never happened.

JEFF WILLIAMS, APPLE’S chief operating officer, has been at the company since 1998, has an engineering background, and has been intimately involved with the Apple Watch’s development since before its launch 10 years ago. I talked to him prior to meeting with Blahnik and Dr. Desai. He’s wearing sporty-looking pants, a fleece top, and Nikes, and he looks ready for a run or a brainstorm. He’s quick to smile, but also direct and focused. In his telling of the origin story of the Apple Watch, it was all about fitness. “Our original thinking was narrow,” he says. “We thought our biggest contribution would be activity, getting people to be more active. We put the photoplethysmography, the heart rate sensor, on the first watch purely to help with accurate calorie tracking along with the accelerometer.”

After the watch debuted, the letters and emails that Apple received fell into two main categories, he says. The first: “Hey, you’re helping me be more active.” The second: “Hey, because you have a heart rate monitor on it, it saved my life.” “We didn’t really split atoms or anything; it was just heart rate monitoring. You could do that by, you know, putting a finger on your pulse and watching the clock. But the fact that you can do it doesn’t mean that you do do it. It really dawned on us that there’s a huge opportunity, and even a moral responsibility, to go help people, because we have this ability to detect some things. So we started pulling on threads and pursuing things and started adding more new sensors. Our motivation is to keep doing more in this space and exploring and figuring out how we can have the most impact.”

However, when asked about the biggest decision he’s had to make regarding the watch over the past decade, Williams says, “Probably the most fundamental decision is—a lot of people advised us to stay away from the medical side, because it’s a whole different can of worms to the fitness and casual wellness stuff in terms of regulatory approval and having your products be medical devices. But we looked at the impact we could have and said, ‘We’re going after that.’” Apple founder Steve Jobs would likely have approved. He was known to be fond of a quotation that speaks to anticipating the future: “There’s an old Wayne Gretzky quote I love. ‘I skate to where the puck is going to be, not where it has been.’ And we’ve always tried to do that at Apple.’”

Where the puck of wellness is going to be is more accurate and advanced health metrics. Williams notes that because the watch is “on hundreds of millions of wrists,” Apple has a responsibility to do things in a clinically validated way to ensure its health data is rock solid. He cites the example of Apple’s new breathing disturbance metric and sleep apnea notification. The watch’s accelerometer detects small movements at the wrist associated with interruptions to normal respiratory patterns during sleep. The sleep apnea notification algorithm was developed using advanced machine learning and an extensive data set gathered from clinical-grade sleep apnea tests. The feature was then validated in a clinical study of 1,499 people—unprecedented in size for sleep apnea, says Williams—and earned FDA approval in 2024.

Sleep apnea affects 30 million Americans, according to the American Academy of Sleep Medicine, and an estimated 80 percent of cases are undiagnosed. That’s another massive number. If a wearer gets a notification about an elevated level of breathing disturbances over 30 days, indicating possible sleep apnea, Apple provides a PDF with a chart noting the disturbances and a QR-code link to Apple’s research for the wearer to give to their health provider. It’s a feature that could empower millions of people with greater knowledge about the quality of their sleep and even help them discover a potentially dangerous medical condition.

How digital health technologies can help patients is a hot research area, especially given the rising burden of chronic disease. Geoffrey Ginsburg, MD, PhD, is the chief science and medical officer for the National Institute of Health’s All of Us study, an effort to enroll a diverse cohort of 1 million people and build a robust database—everything from digital health-tracker data to surveys on mental, social, and environmental determinants of health to genomic sequencing—that can inform thousands of studies on a variety of health conditions, with the goal of advancing precision medicine for everyone in America. “We’re trying to dispel and dispense with the paternalistic health system where the doctor tells the patient everything they need to do,” he says. “We can do this more and more ourselves by having access to our own data, having access to tools and the Internet that give us a way to take our health decisions into our own hands versus having them dictated to us from a health provider. Not that they’re going to go away completely, but I think we’re seeing that shift of participant empowerment.”

Dr. Ginsberg is bullish on digital health trackers, noting that technological advances now allow people to measure things they haven’t been able to measure before. He points to positive data, “proof points,” regarding how people using basic step trackers have had success in fighting chronic diseases such as diabetes and obesity. “It’s gratifying when a device tells you you’ve reached your goal for the day, whatever that is,” he says. “That positive reinforcement is very powerful—and you don’t have to go to your doctor, your health professional, or a nurse to get that information. You get it right in the comfort of your own home.”

How do I stay healthy? How do I lose weight? How do I understand what I’m eating and make changes that can help me get to my ideal weight? How do I achieve an ideal sleep pattern? Dr. Ginsberg believes that digital health technology can help answer all those questions, and he’s especially excited to see progress regarding sleep. “The medical community has done a poor job at understanding sleep,” he says. “We’re starting to understand the ways sleep influences chronic disease and how chronic disease influences sleep. Those two things are really important to give people better recommendations about how to achieve better sleep and better health.”

As digital trackers evolve from gauging activity to gauging health, Dr. Ginsberg stresses the importance of manufacturers rigorously proving that their devices are measuring what they’re supposed to be measuring and earning FDA approval. He warns that with all this information—especially when monitoring things continuously over time, such as heart rate and sleep patterns—it’s vital to be able to figure out what’s the signal and what’s the noise, what’s critical data that might prompt you to see your health-care provider and what you can ignore. “It’s a great leap forward in health care in general for people to use a device and to have confidence that the information they’re getting is valuable health information,” he says. “It’s not just a gaming platform; it’s something that can really impact their health.”

Dr. Ginsberg anticipates an even more tech-forward wellness future: sensors you ingest, tattoos that change color, micro cameras, nanobots, and other innovations. “We’re just seeing the beginning of a true revolution in technology that will change how people manage their health.”

AS DIGITAL HEALTH trackers continue to evolve, our relationship with technology becomes both more complicated and more nuanced. Andy Galpin, PhD, CSCS, is the executive director of the Human Performance Center at Parker University and known for being the guy Huberman goes to when he wants fitness advice. Galpin also runs his own sleep and performance clinics for top athletes, CEOs, and anyone else who wants to get in the best shape of their life. He appreciates the role of wearables in giving people “a high level of calibration and accountability” in terms of their activity and in helping people be more aware of their sleep patterns and overall health. And while he’s optimistic about new technology that will offer researchers higher-fidelity data on many different metrics, he also sounds a warning.

“In the current moment, people should be extraordinarily cautious of outsourcing their entire physiology to technology,” he says. “The argument is not with technology per se; it’s the bigger argument of ‘Are we sure we’re even aiming at the right targets?’” He gives examples of various biomarkers that can tell doctors when a disease may be present, but there’s less evidence for what a healthy level should be. He’s also wary of readiness “scores” and other algorithmic measures that rely on databases that may not be diverse or large, so when you get your score, good or bad, you should think about who you’re being compared to. “Just maintain some sobriety and your own responsibility to yourself and not just be like, ‘Well, the device knows what it’s doing,’” he says. “You have to understand that these are tools; they’re not at the stage where they’re taskmasters.” He also notes that goal-setting features can backfire, reminding you of failure rather than success. He points out the rise of orthosomnia, the obsessive pursuit of optimal sleep driven by sleep tracker data. Like any relationship, things can get toxic and sometimes taking a break from your wearable, or turning off notifications, can be beneficial.

Many of these issues are things that Apple has thought about a lot, hence the seemingly slow rollout of major new health features. Clinically-validated research tends to take two to four years, notes Dr. Desai. Apple also began its own research into heart health and movement in 2019, with the users consent, and that information helps inform the evolution and release of new features. Apple is also adding features that make the watch even more customizable: To better help you become the person you want to be, it becomes the guide you want and need. Remember the Move, Exercise, and Stand rings that Blahnik is so proud of? Earlier in 2024, Apple introduced a feature that allows you to set different calorie-burn goals for specific days and temporarily pause your streaks to take a guilt-free day off.

Blahnik says a decade in, the timing was right for a change to the rings. “Imagine if, out of the box, the rings allowed our users in the very beginning to pick every single day differently,” he says. “It just would’ve been full of a lot of friction. Having the same goal every day is sticky; it allows people to not get caught up in the complexities of variation. But when you start to realize the sentiment of what users give you feedback on, you realize that there’s more opportunity there to bring more people in. We’re always wanting to make it as inclusive and welcoming as possible. But after 10 years, what we learned is there are a lot of people where weekends look different than weekdays or they drive a lot on a Tuesday and they can’t meet their goals. This idea of customization became really important to us.”

He shares that in his own mind, a streak is something that eventually ends and you begin again. “I’m okay with that, because to me that’s what’s motivating: I got to this many days and I want to start over. But for a lot of people, a streak represents much more to them than they’ve just been active. To them it’s about consistency and all of that. It was about balancing this notion of allowing the behavior change experience to exist and to make people passionate about it. But if they want to take a pause because they don’t want it to count, we also want to make that available to them.”

Blahnik says the Watch teams—health, fitness, design, and others—met to discuss allowing users to pause the rings, noting that lots of people weighed in but the dialogue was not contentious. “Feedback is part of Apple’s culture, and it’s valuable because lots of people have strong opinions and we welcome that and debate all the sides,” he says. This customization option gives the watch a more forgiving bedside manner, more cheerleader-like, which could ultimately help users reach their goals if the drill sergeant approach is not working for them.

Another new feature that shows off a more complex side to Apple Watch 10’s personality is a fitness feature called Training Load. It uses accumulated biometric data (heart rate, respiratory rate, sleep duration for a month) and user input to establish a baseline, then provides a daily rating on a scale from “well below” to “well above” to gauge how much exertion you might be able to handle that day compared to your standard capacity. This can help you make better decisions about your workouts within the larger context of your exercise program. Cardio sessions like running, cycling, and swimming are given automatic effort ratings (from 1: Easy to 10: All Out), and users are prompted to manually adjust the score based on their perceived level of effort. (They can also opt into prompts to rate other types of workouts, like strength training.) The goal is to bridge the gap between the data collected via the device and the wearer’s actual experience, since factors like mood or humidity or stress level can play a huge role in how hard a training session feels.

Blahnik emphasizes that the guidance from Training Load is not binary, as in train or don’t train, but more nuanced. He says that while they expected the “rate your workout” feature in Training Load to appeal mostly to “pro users” (a.k.a. fitness buffs), it’s also compelling to beginners. “What we saw in our testing is that it’s useful because a lot of people finish their workouts and they don’t even take a minute to think about how they feel or where they’re at. Did I go easy? Did I go hard? All of a sudden they’re starting to see how they can make improvements.” More broadly, Blahnik says, many people use the feature to be consistent: They may not even want to get better, but they want to make sure they’re not declining—and the chart feature lets them see that.

As for what’s next, both Blahnik and Dr. Desai donned their poker faces and would not comment, except to say that the best years are ahead for the Apple Watch. Ditto Williams, who also said he feels like “we’re just at the beginning. It’s harder and harder sensor-wise, and there’s only so much you can detect non-invasively about the human body, but we’re not giving up, and we’re excited about some of the things we’re working on in the future.”

Although we’ve been talking about fitness features and the role of the watch in boosting your health, Williams notes that “if Apple tried to sell a product that said, ‘Hey, here’s your device for apnea detection,’ most people would say, ‘That’s really not me.’ But the fact that it’s the same device you wear to grab a message or to track your exercise or whatever, that it can alert you to the fact that you have apnea or that you have A-fib or an irregular or high heart rate or what have you—we sort of ambush people with really good information about their health, and it helps them in that way.”

That reminded me of a conversation I had with an Apple employee at the launch of Series 10 watch last September. We were talking about all of the watch’s new health and fitness features, its brains and power, and which faces best showed all the data, whether it’s the Modular Ultra or Nike Hybrid or some of the more soothing faces like Breathe or Reflections. And we got onto which faces seemed to be the most popular. His answer: The one that lets you sync a photo album to the face so that a new image pops up whenever you move your wrist or tap the display, in what feels like a (cleverly engineered) random act of kindness. Given that research shows that people look at their watch about 80 times per day, that’s a lot of kindness, and it may help explain the Apple Watch’s massive popularity and its efficiency and role as an ally in helping people be more active, healthy, and happy.