Latest news with #EikoFried
CNET
5 days ago
- Health
- CNET
Your Smartwatch's Sleep Tracker May Be Sleeping on the Job
If sleep is important to you -- and it should be -- you might want to think twice before you put a lot of stock in the latest stress charts from your fitness wearable. A recent study from the Netherlands' Leiden University, published in the Journal of Psychopathology and Clinical Science, has found that when smartwatches and similar devices record readings on stress, fatigue or sleep, they're frequently getting it wrong. Researchers studied 800 young adults using the same Garmin Vivosmart 4 smartwatch model. They compared the data the smartwatches produced with the reports that the users created four times per day about how sleepy or stressed they were feeling. Lead author and associate professor Eiko Fried said the correlation between the wearable data and the user-created data was "basically zero." A representative for Garmin did not immediately respond to a request for comment. Stressed or sex? Your watch doesn't know So why do wearables like fitness smartwatches get it so wrong? Their sensors are fairly limited in what they can do. Watches like these need to be worn correctly at all times (a loose or tight watch may give poor readings, for example), and they typically use basic information like pulse rate and movement to make guesses about health. Those guesses don't always reflect real-world scenarios. A wearable may identify high stress when the real cause of the change was a workout, excitement over good news or sex. There are so many potential alternatives to stress or fatigue that the watches in the study never really got it right -- and the devices sometimes guessed the complete opposite emotional state from what users recorded. The Dutch study did note that Garmin's Body Battery readings, which specifically measure physical fatigue, were more reliable than stress indicators, but still inaccurate. And sleep sensing performed the best of them all, with Garmin watches showing a two-thirds chance of noting the differences between a good night's sleep and a bad one. It's also worth noting that smartwatch sensors can become more accurate as technology improves. It would be interesting to run a similar study with the newer Garmin Vivosmart 5 to see if anything has improved, as well as see if other models like the latest versions of the Apple Watch have similar accuracy results.
CNET
5 days ago
- Health
- CNET
New Study Shows Smartwatch Stress Sensors Have No Idea What They're Doing
You might want to think twice before you put a lot of stock in the latest stress charts from your fitness wearable. A recent study from the Netherlands' Leiden University, published in the Journal of Psychopathology and Clinical Science, has found that when smartwatches and similar devices record readings on stress, fatigue, or sleep, they're frequently getting it wrong. Researchers studied 800 young adults using the same Garmin Vivosmart 4 smartwatch model. They compared the data the smartwatches produced with the reports that the users created four times per day about how sleepy or stressed they were feeling. Lead author and associate professor Eiko Fried said the correlation between the wearable data and the user-created data was, "basically zero." A representative for Garmin did not immediately respond to a request for comment. Stressed or sex? Your watch doesn't know So why do wearables like fitness smartwatches get it so wrong? Their sensors are fairly limited in what they can do. Watches like these need to be worn correctly at all times (a loose or tight watch may give poor readings, for example), and they typically use basic information like pulse rate and movement to make guesses about health. Those guesses don't always reflect real-world scenarios. A wearable may identify high stress when the real cause of the change was a workout, excitement over good news, or sex. There are so many potential alternatives to stress or fatigue that the watches in the study never really got it right -- and the devices sometimes guessed the complete opposite emotional state from what users recorded. The Dutch study did note that Garmin's Body Battery readings, which specifically measure physical fatigue, were more reliable than stress indicators, but still inaccurate. And sleep sensing performed the best of them all, with Garmin watches showing a two-thirds chance of noting the differences between a good night's sleep and a bad one. It's also worth noting that smartwatch sensors can become more accurate as technology improves. It would be interesting to run a similar study with the much newer Garmin Vivosmart 5 to see if anything has improved, as well as see if other models like the latest versions of the Apple Watch have similar accuracy results.
Hindustan Times
6 days ago
- Health
- Hindustan Times
Stop trusting your smartwatch stress score right now, new research says it often gets your mood completely wrong
Smartwatches promise a quick read on your day: heart rate, sleep, stress, and a nudge to breathe when things spike. A new peer reviewed study suggests one of those signals may be far less reliable than users think. When it comes to stress, consumer wearables can confuse excitement for strain and flag you as overworked when you are simply having fun. Smartwatches can label excitement as stress. Sleep hours are more reliable, but how rested remains hard to read from a wrist.(Unsplash) What the study actually found Researchers tracked 800 young adults wearing Garmin Vivosmart 4 bands for three months. They compared the devices' stress, fatigue, and sleep scores with how participants said they felt in the moment. The headline result was blunt. On stress, there was 'basically zero' correlation with self reported feelings, according to lead author Eiko Fried of Leiden University. He noted that his own watch has labelled him stressed at the gym and during a friend's wedding, situations where elevated heart rate and arousal are normal but not negative. The point is not that wearables are useless. It is that they measure physiology, not context. A pulse spike can mean anxiety, excitement, caffeine, or a sprint for the bus, and the algorithm does not always know which is which. Fatigue tracking did a little better, though still short of a clinical read. Sleep tracking was the strongest of the three, particularly for time in bed. About two thirds of participants saw a clear match between nights they felt good and nights the watch logged roughly two extra hours of sleep. Even there, the devices were better at counting hours than judging how rested someone felt. That makes sense for consumer sensors that infer sleep stages from movement and heart rate rather than EEG. How to use these scores without overreacting Treat stress metrics as a rough guide, not a diagnosis. A spike can be a useful prompt to take a break, drink water, or step outside. It is not proof that your workload is toxic or that you need to overhaul your life. If your watch regularly cries stress during workouts, social events, or after coffee, consider adjusting alert thresholds or turning off real time stress tiles to avoid alert fatigue. Use trends over weeks, not moment by moment swings, and pair the numbers with a quick check in: How do you feel right now? Sleep remains the most practical signal for daily decisions. If longer nights line up with better mornings, let that guide your bedtime. For fatigue, look at multi day patterns rather than single day dips. And remember the researchers' caution: these are consumer devices, not medical tools. They can help you notice patterns. They cannot read your mind or your mood with clinical accuracy. The hope is that studies like this will steer better models that factor in context and multi sensor data for early mental health screening. Until then, keep what works, step counts, sleep duration, heart rate trends, and keep stress scores in their lane as a lightweight prompt, not a verdict. The study was published in the Journal of Psychopathology and Clinical Science .
Indian Express
7 days ago
- Health
- Indian Express
Your smartwatch may be lying about your stress levels, study finds
Millions of people use smartwatches to track their stress levels, but a new study seems to be casting a shadow of doubt on the data gathered by wearables. A recent study published by the American Psychological Association suggests that there is no connection between device records and how a person feels. The study is about 'Associations between ecological momentary assessment and passive sensor data in a large student sample'. It suggests that self-reported stress levels and data that is acquired by wearable technology, which includes smartwatches, can be useful if the user is aware of its restrictions. The researchers used a Garmin Vivosmart 4 activity tracker to monitor the stress levels of 800 young adults for a time span of 3 months. Where the participants were asked to score how stressed, tired, or sleepy they were four times a day. Eiko Fried, co-author of the research, said that the results were hardly surprising. Garmin Vivosmart 4 usually monitors heart rate, which is not related to one's emotional state. Heart rate usually rises during sexual arousal as much as it does during anger. This demonstrated that the watches were not providing any valuable information about the user's emotional state. When the researchers compared the data, they found little connection between the numbers from the smartwatches and what people felt. Out of all 800 participants, not a single person had a 'stress score' on their tracker that matched their true feelings. For a quarter of the group, their smartwatches showed the exact opposite of what they were experiencing, for example, telling them they were relaxed when they felt anxious, and vice versa. They also looked into how reliable Garmin's 'body battery' feature is, which is supposed to measure physical tiredness. The results showed a slightly stronger link between this data and what people felt, but it wasn't strong enough to be meaningful. The researchers believe that the body battery score is calculated by combining pulse and activity levels. Furthermore, while the devices were good at tracking how long people slept, they weren't good at telling how rested someone felt upon waking up. Fried noted that this raises important questions about what wearable data can really tell us about our mental health. Nevertheless, researchers believe this kind of sleep data could help developers create a warning system for depression, alerting users to a potential episode so they can take preventive action.
The Guardian
08-08-2025
- Health
- The Guardian
Smartwatches offer little insight into stress levels, researchers find
They are supposed to monitor you throughout the working day and help make sure that life is not getting on top of you. But a new study has concluded that smartwatches can't accurately measure your stress levels – and may think you're overworked when really you're just excited. Researchers found almost no relationship between the stress levels reported by the smartwatch and the levels that participants said they experienced. However, recorded fatigue levels had a very slight association with the smartwatch data, while sleep had a stronger correlation. Eiko Fried, an author of the study, said the correlation between the smartwatch and self-reported stress scores was 'basically zero'. He added: 'This is no surprise to us given that the watch measures heart rate and heart rate doesn't have that much to do with the emotion you're experiencing – it also goes up for sexual arousal or joyful experiences.' He noted that his Garmin had previously told him he was stressed when he was working out in the gym and when excitedly talking to a friend he hadn't seen for a while at a wedding. 'The findings raise important questions about what wearable data can or can't tell us about mental states,' said Fried. 'Be careful and don't live by your smartwatch – these are consumer devices, not medical devices.' Fried said although there is a lot academic work looking for physiological signals that can act as proxies for emotional states, most aren't precise enough. This is because there is an overlap between positive and negative feelings – for example, hair standing on end can signal anxiety as well as excitement. Fried, an associate professor in the department of clinical psychology at Leiden University in the Netherlands, and his team tracked stress, fatigue and sleep for three months on 800 young adults wearing Garmin vivosmart 4 watches. They asked them to report four times a day on how stressed, fatigued or sleepy users were feeling before cross-referencing the data. And the results, published in the Journal of Psychopathology and Clinical Science, found that none of the participants saw the stress scores on their watches meet the baseline for significant change when they recorded feeling stressed. And for a quarter of participants, their smartwatch told them they were stressed or unstressed when they self-reported feeling the opposite The relationship with physical fatigue, described by Garmin as 'body battery' was 'quite a bit stronger than for stress but overall quite weak' said Fried. Garmin does not disclose the calculations it uses to work out the body battery score, though he suspected it was a combination of a pulse measurement and activity levels. The relationship with sleep was stronger again, though Fried noted it measures sleep duration and tells us little about how well rested someone is, other than the fact there tends to be a relationship between how long you sleep and how well rested you feel. There was a significant association between the Garmin and self-reported data for two-thirds of the sample for sleep. The researchers noted that in nearly all cases, if participants went from one day of self-reporting bad sleep quality, to another day with a good score, they could predict an increase in sleep duration on the Garmin of around two hours. 'This is a really noticeable effect,' they said. The research is intended to feed into an early warning system for depression, in which wearable tech users receive data that will help them receive preventive treatments before an episode begins. So far, there are promising signs that lower activity levels could be a predictor, though Fried has been unable to identify whether this is because of exercise's protective effect against depression or because people feel less energetic as their mental state deteriorates. 'Wearable data can offer valuable insights into people's emotions and experiences, but it's crucial to understand its potential and limitations,' said Margarita Panayiotou, a researcher at the University of Manchester, after reading the study. 'This research helps clarify what such data can reliably reveal and makes an important contribution to ongoing discussions about the role of technology in understanding wellbeing. It's important to remember that wearable data does not necessarily represent objective truth and should be interpreted alongside broader context, including individuals' perceptions and lived experiences.' Garmin has been approached for comment.
