Featured Image Credit: @CoachDanGo / X
A fitness expert has put four of the biggest health trackers on the market to the test at the same time, and the result might make you think twice about trusting every number on your wrist.
Wearable tech has become a huge part of how people track their sleep, recovery, workouts, and even stress levels.
Between the Apple Watch, Whoop, Oura Ring, and Google’s new Fitbit Air, there are now plenty of options for anyone who wants to know more about what their body is supposedly doing.
Whilst each company promises useful health insights, one fitness coach decided to find out what actually happens when you wear them all together.
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Dan Go, who runs The High Performance Journal — also sharing his findings across social media platforms, like his X (formerly Twitter) — said: “For a full week, I strapped 4 of the most popular health trackers onto my body at the same time: The Apple Watch, Oura, Whoop, and the new Fitbit Air from Google.”
He added: “I assumed they would more or less agree, then I'd tell you which one I recommend, and we'd all move on with our lives.
“That's not what happened.”
Go’s biggest surprise came from the sleep data, where the devices broadly agreed on total sleep time but then split dramatically when it came to the finer details.
According to Go, one morning saw one device tell him he had 81 minutes of deep sleep, while two others claimed he had 47 minutes.
That is a pretty huge difference when deep sleep is one of the main stats many people obsess over when checking their health tracker every morning.
Go wrote: “Deep sleep is where it fell apart.”
He explained that it was Apple and Oura specifically which both placed him at around 47 minutes a night, while Fitbit and Whoop put him at 70 and 81 minutes.
The fitness expert added: “That's a 76% spread on the exact number people stress about.”
REM sleep was also inconsistent, with Apple coming in higher than the other three devices.
Go’s conclusion on sleep was not that every tracker is useless, but that users should probably be careful about treating sleep stages as fact.
As ‘the big lesson, he wrote: “Trust your sleep duration and your trend. Ignore the stage-by-stage breakdown. And never, ever compare your deep sleep to a friend on a different device. You're comparing 2 guesses.”
I wore an Apple Watch, Whoop, Oura, and Fitbit Air at the same time for a week.
— Dan Go (@CoachDanGo) June 24, 2026
I expected the data to be similar but did not expect this.
Here's what every wearable owner needs to know: pic.twitter.com/poWZKyOxSi
Steps were another area where the devices did not all agree, as Go used a basic pedometer as a comparison and found Apple and Fitbit came closest; meanwhile, Whoop consistently gave him more steps than he had actually taken.
Oura was slightly different, as he sometimes removed the ring for lifting, swimming, and other activities, meaning it could not track everything he did.
The recovery scores also left him unconvinced, with Go saying two devices scored the same body across the same week very differently.
He wrote: “I didn't act on any of it. 20 years into coaching my own body and other people's, I've learned that wrist and finger HRV aren't accurate enough to drive decisions. The exception is getting HRV off a chest strap.”
As for which of these four fitness trackers actually came out on top, Go said it ultimately depends on what kind of user you are, but admitted: “If I had to wear one tracker for the rest of my life, it would be the Apple Watch, purely because it's the most versatile.”
Still, the final point he was trying to make is that his study was about a mindset that’s bigger than simply picking a winner.
He concluded: “The best wearable is the one that changes a decision. If it doesn't change your decisions, then it's okay to not wear it.”
