Technologies

Your Smartwatch’s Sleep Tracker May Be Sleeping on the Job

Stress sensors are inaccurate and sometimes report the opposite of user experiences, new research finds

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.

Technologies

Call of Duty: Black Ops 7 Leak Claims Nov. 14 Release Date, No Switch 2 Version Yet

What new conspiracies will be revealed in Black Ops 7?

Call of Duty: Black Ops 7 will be the next entry in Activision’s military shooter series, which typically comes out in October every year, making it one of the last big game releases before Black Friday. A leak suggests that the new CoD might come out a little later than usual, but still in time for the big shopping day.

Black Ops 7 will reportedly be released on Nov. 14, according to a leaker who goes by the name billbil-kun from a post on the French website Dealabs. Along with the supposed release date, the leak says there will not be a Switch 2 version when the game launches.

A spokesperson for the franchise said in an emailed statement that details about Black Ops 7 will be revealed at Gamescom Opening Night, which is this coming Tuesday, Aug. 19.

The Call of Duty series release dates typically straddle the late October and early November period. The last CoD game to come out mid-November was Black Ops Cold War, which was released on Nov. 13, 2020. It’s unclear if the later release was due in part to Battlefield 6 coming out on Oct. 10, which would allow for some time between the releases of the two popular military FPS games.

The lack of a Switch 2 version at launch could mean that the team working on that version of the game needed some more time before its release. While the original Switch has become too underpowered for modern games, Nintendo boosted the performance of the Switch 2, which makes it capable of running more graphics-intensive games, potentially including Call of Duty. Black Ops 7 will still likely be released on PC, PS5 and Xbox Series X and Series S on launch day as it is every year.

In Black Ops 7, players will jump into the role of David Mason, played by Milo Ventimiglia. The year is 2035, and Mason is struggling with hallucinations of enemies from his past. The character was first introduced in 2012’s Black Ops 2 and was also in 2024’s Black Ops 6.

While other Call of Duty games tend to focus on certain eras of warfare, such as World War II and the Iraq War, the Black Ops series focuses on secret missions typically conducted by the US and range from the Cold War era to more modern and even futuristic times. Black Ops 2 took place in 2025, while Black Ops 6 was set in 1991.

Technologies

Beijing’s ‘Robot Olympics’ Are Off and Running (and Falling)

Strike up the Chariots of Fire theme and grab a flag, the futuristic Games are on.

China just turned a pair of Olympic venues into a playground for robots.

The inaugural World Humanoid Robot Games, running from Aug. 15-17, opened Friday with soccer, sprints, kickboxing and table tennis, as well as a healthy number of face-plants. The games feature 280 robot teams from 16 countries and hundreds of bipedal bots vying for medals and whatever passes for bragging rights to robots.

Events are split between two 2022 Winter Olympics landmarks: China’s National Stadium and the National Speed Skating Oval. On the schedule: track and field, football (soccer to Americans), table tennis, and «scenario» trials such as medicine sorting, cleaning services and industrial handling—the kind of practical skills that robot-makers actually care about.

The highlight reel revealed more chaos than control: robots colliding mid-match, sprinters crumpling mid-stride and kickboxers needing a reboot. But there were bright spots, too. Some bots popped back to their feet unassisted and even finished middle-distance runs as handlers puffed behind them. There was even a 1,500-meter race. Tickets ran 128–580 yuan (about $18–$81).

The robot athletes are supplied by a combination of academia and industry, including China’s Unitree and Fourier, with squads also from the US, Germany, Brazil, Japan and more. Organizers pitch the weekend as data collection under pressure, with sports forcing the robots to demonstrate balance, vision and decision-making, all of which later will translate over to the robot’s work in factories, logistics and as home helpers.

China is using the Games to showcase its bet on embodied AI — software linked to machines that can navigate human spaces. The country has poured billions of dollars into robotics and is planning a 1-trillion-yuan ( about $137 billion) fund for startups as part of a push to counter an aging-workforce crunch and compete in advanced manufacturing.

Rules vary by event, but organizers say competitions span autonomous control and remote operation: either way, no mid-match «player swaps» for fresh robots are allowed. That means lots of stress testing on robot batteries, heat management and recovery behaviors in real-time chaos.

The Associated Press has streamed some of the Games if you want to check it out.

The event runs through Aug. 17.

Technologies

Today’s Wordle Hints, Answer and Help for Aug. 16, #1519

Here are hints and the answer for today’s Wordle, No. 1,519 for Saturday, Aug. 16.

Looking for the most recent Wordle answer? Click here for today’s Wordle hints, as well as our daily answers and hints for The New York Times Mini Crossword, Connections, Connections: Sports Edition and Strands puzzles.

Today’s Wordle puzzle was a puzzler for me. I know the answer word, and the letters aren’t super-rare, but I didn’t seem to be able to put them in the right places. If you need a new starter word, check out our list of which letters show up the most in English words. If you need hints and the answer, read on.