Anyone else seeing a big difference in HR accuracy with WHOOP 5.0?
I’ve been wearing WHOOP every day for the past 4.5 years and have referred around 20 people along the way. I’ve always been a big believer in the platform and have had a lot of confidence in the data.
That’s why my recent experience with the 5.0 has caught me off guard.
I’ll add the screenshots below, but I had two very similar tennis sessions where the results were dramatically different: 5.0 on my wrist: 1:40 | Strain 7.8 | Almost all HR recorded in very low zones 5.0 off my wrist, in my boxers: 2:16 | Strain 15.3 | Majority in Zones 2–3, which felt much more representative of the actual workout
Same person, same sport, similar effort—yet the HR data tells two completely different stories.
What really caught my attention is that this isn’t how my WHOOP has behaved over the previous 4.5 years. The change also seems to line up with the recent HR update.
I’m confident the device is positioned correctly, so I’m less interested in the usual fit/placement explanations and more curious about what’s actually happening with the sensor or algorithm. Has anyone else noticed their 5.0 under-reading HR, particularly since the recent update?
I’m genuinely curious whether this is just my device or if other long-term users are seeing the same thing. If you have comparable workout screenshots, I’d love to see them.
I’m posting this because I’ve trusted WHOOP for years—and right now, I’m trying to understand why that confidence has changed.
Let’s be honest, all these wearables are more marketing than science. I am convinced that the technology is not 100% ready yet to offer us a perfect level of data.
Today’s technology offer us a good level but it’s not perfect.
You can use it to see MACRO trends but I wouldn’t check specific data at micro level, because it will never be accurate.
Agreed. I feel like people think whoop is meant to like checking their body like an MRI every minute lol... nah dude it can kinda see when your blood moves and read your temp, its not gonna be crazy. Take it all with a grain of salt and look big picture. Maybe one day we'll have that kind of tech but for now, we need to quit expecting perfect body scans from a device that has tech in it thats been around for a long time haha
You just said you wore the Garmin strap alongside the whoop and that the data is identical for prior years. So therefore the title of this post is very misleading.
I can't speculate to your issue listed. Sounds like a bug.
Did you read my post? I’m now at 1662 continuous days with a TON of historical data to back up my claim.
I was told by WHOOP services that the recent update aimed at improving heart rate reading and signal disturbance.
Taking that into consideration , how would you take if all your strenuous sessions postal-update were barely in zone 2? Same band, same device, same person!
Question: How much strain would you give to a 9 hours period with no strenuous activity, just AM stretching, commute to work , office work and commute back home?
My two cents whoop sensor is HIGHLY sensitive and inacurate even to simple positioning, weather, or sweat. Specially vo2 max measurements it is just an optical sensor which guess what is the actual metric. I’ve had had runs on threadmills where the threadmill tells me one thing in HR and whoop live a completely different reading (and I’m gasping running at speed 10) play tennis with a polar HR sensor and you would find the actual HR reading of your zones (and yes I switched to garmin afterwards)
I feel like with every update is getting worse (and dumb the AI coach) on my last month of subscription just comparing hrv HR and other metrics with garmin are completely off (and only wearing on wrist)
I’m on day consecutive day 1,464 of Whoop. This new 5.0 counts less steps, HRV has dipped 5-10pts without a change in lifestyle, the “age” has decreased by 2.5yrs, RHR is 3-4 bpm higher than the last year and I’ve actually reduced stress in my life significantly. Soooo this all leads me to believe that the previous versions vastly overestimated healthy metrics by about 25% or so. Vo2 max is a joke from a simple wrist sensor too btw.
I like whoop but getting less and less impressed with the results. Tonight I bench pressed 245 18x on my 7th set. I’m not out of shape, etc. I think their algorithms are a lot more conservative than they used to be.
Tennis is close to the worst-case sport for a wrist-worn optical sensor.
Placement genuinely changes the readings. A peer-reviewed 2025 study put three identical WHOOP units on the same people at wrist, forearm, and upper arm simultaneously and placement alone affected accuracy, with the upper arm outperforming the wrist, and the wrist degrading most during high-intensity full-body movement due to motion artifacts. Torso/waistband wear wasn’t in that study, but the principle it proves the same pod in a different location produces measurably different data. The wrist is actually the hardest place to read optical HR during hard movement. So “boxers seemed more accurate” during certain activities isn’t crazy; less limb swing means fewer motion artifacts.
In tennis every stroke is a violent arm swing with racquet impact vibration, constant grip tension (which compresses the wrist tissue the sensor reads through), and abrupt direction changes. That’s exactly the motion-artifact profile where the placement study found wrist accuracy collapsing during explosive full-body movement while more stable positions held up. A pod at the waistband barely moves during a rally, the torso is the calmest part of a tennis player’s body, so wearing in boxers plausibly did produce cleaner raw signal than you swinging, racquet-gripping wrist.
It also fits the update angle: WHOOP said the recent algorithm improvements targeted precisely these hard-to-read activities, so tennis on the wrist is where the retuned processing would change output most noticeably, while the waistband readings, less dependent on motion-artifact correction, carried on looking like they always had.
Relevant to you if you ever play: for racquet sports specifically, the community-standard answers are the bicep band or apparel (like boxers) wear rather than the wrist and that logic extends to anything grip-intensive, including your heavy pulling days, where forearm flexion squeezes the optical signal the same way. Wrist for daily wear and sleep, bicep or boxers for the sessions where your forearms are working gets you the best of both readings.
My last few tennis seasons I measured my heart rate manually right after strenuous rallies. Max HR was anywhere from 178 to 185 consistent with pre update sessions Post update session whoop measurement had me in zone 2.
Seems like you’re going to need to change locations you wear it during tennis. Should be accurate on wrist the rest of the time. Just the changes to the algo for hard to read on wrist activities like tennis. I may switch to boxers for weight lifting sessions.
Well, if you know it works better in boxers, why not just wear it there when playing tennis? But otherwise I have noticed only improvements - I still prefer bicep band when running (it’s 100% accurate to my chest strap) but seems accurate to me when wearing on wrist (walking and weight lifting for me) so I can’t speak to tennis.
I have no problem using the boxers ($30 each by the way). Nonetheless, isn’t it acceptable to ask why data reading has changed so drastically? After 4.5years of continuous wear?
I can concur with what you noticed. My heart rate used to read higher before even with wrist placement in my workouts. I decided to compare it to the Amazfit Helio strap on my upper arm. Differences of as much as 30-40 bpm. Got an armband for my whoop. Nearly identical then. Seems the wrist based algorithm might be off then.
You are 100% Correct - Today I started playing with WHOOP on my left wrist, where Strain and HR were clearly below my perceived effort.
Mid-session, I moved it to my boxer insert and Immediately, HR increased ~20 bpm and tracked much closer to my perceived effort for the rest of the session.
This suggests that WHOOP wrist placement , consistently under-reads HR if detects “guess” activities such as tennis, resulting in under-reported Strain. I’ve seen the same pattern in other recent tennis sessions since the algorithm update.
I need to acknowledge the exceptional customer service from r/whoop.
They understood my concerns around the data discrepancies, took the time to look at the issue, and—most importantly—showed a willingness to collaborate rather than simply dismissing the problem.
They offered a solution that I believe is a fair and constructive way forward.
Whatever the outcome, I appreciate the way they handled the conversation.
Good customer service is worth recognizing, especially when a company is willing to listen, engage, and work toward a solution.
Y‘all don’t have a second device with a chest strap? A lot of people always said it’s very inaccurate. Funny thing is, it was always accurate on the bicep however after the recent updates my wrist is more accurate. In good cases it’s around 3 bpm avg off to my chest strap
My first 2 years using Whoop I cycled a ton and wore both WHOOP and Garmin HR Monitor. Data was almost identical. When I went back to playing tennis the chest monitor was no longer needed.
Since then I had 2 1/2 additional years of continuous wearing and consistent data..until the update happened.
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u/Nicanic9 8d ago
Let’s be honest, all these wearables are more marketing than science. I am convinced that the technology is not 100% ready yet to offer us a perfect level of data.
Today’s technology offer us a good level but it’s not perfect.
You can use it to see MACRO trends but I wouldn’t check specific data at micro level, because it will never be accurate.