Inaccurate heart rate during strength training

General
1

Hey everyone,
just wondering if anyone else has experienced similar issues – or found a workaround:

I’ve been using WHOOP since March 2024 and love the concept overall. The form factor is great, and I really want this to be my go-to tool for training, recovery, and health tracking.

But I’ve had persistent and severe issues with HR accuracy during strength training – and unfortunately, even after upgrading to the WHOOP 5.0 MG and receiving a replacement device via support, nothing has improved.

Here’s what happens:
• During heavy strength training (e.g. squats, deadlifts, leg press), my heart rate spikes to 150–160 bpm (confirmed with Apple Watch & chest strap).
• WHOOP, however, shows around 70–80 bpm during the set.
• Only once my HR drops back below ~120–130 bpm (usually during rest) does WHOOP “catch up” – meaning the actual intense effort is completely missed.

This happens consistently, regardless of:
• Tracking method (auto-detect, manual activity, Strength Training, or Strength Trainer)
• Strap position (wrist left/right, forearm, bicep band – all tested with tight/loose fits)
• Sensor care and placement (clean sensor, >2 inches above wrist bone, logo inward)
• Type of movement – it even happens during leg exercises where my arms barely move.

Outside of the gym, especially during cardio, the HR readings are perfectly fine.

I’ve been in touch with WHOOP support , followed all placement recommendations, sent photos, received a replacement unit – but the issue remains exactly the same.

I’m 185 cm, 88 kg, ~15% body fat – nothing extreme anatomically. No tattoos, clean skin, normal wrist size.

At this point, I’m wondering:
Is WHOOP simply not capable of tracking short HR spikes typical in strength training?

Would love to hear if anyone has found a solution – or if others are dealing with the same thing.

Thanks in advance,
Felix

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I’m having a similar issue. My heart rate with my 5.0 was reading around 103-108 for my heart rate while my Apple Watch was reporting around 130-170 BPM… Seems like we’re going to need a firmware update to address this. I was definitely above 108… I am an athlete and can attest that the heart rate monitoring has been inaccurate during my workouts… hopefully Whoop can get this issue corrected in a timely manner if enough members are having this issue? The issue has been during open exercise recordings… my runs seem like they have been recording my HR correctly. I’ll need to pay attention to this during some of my biking sessions. My daytime heart rate during rest seems to be fine and inline with my other tracking devices.

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I also posted on Reddit and got tons of replies and messages. So we’re definitely not alone with this issue. I am also in contact with support AGAIN but seems like they can’t help with it. They try to blame it on how I am wearing the band but I am wearing it exactly like recommended, tried it on both wrists, inside and outside, on the bicep, even on my ankle. But the readings are the same each time. I just hope more people will write support with the exact same problem so they finally realize they have to change something.

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I just got the whoop 5.0. I always used a Garmin Venu 3 which was within 1 beat of the heart rate monitor of the exercise machine. My whoop is constantly 20-40 beats lower during strength training. It clean, almost new and fitted properly.

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Yeah that’s super frustrating.

I have also posted on Reddit and talked to friends and got more than 20 replies from people having the exact same issues. If you dig a little there are also YT videos showing the exact same thing.

I just hope enough people write the support for them to change something because I still think it might be a software issue and not an actual hardware issue.

I am also in contact with support. They’re answering quickly and seem to be really interested in solving this issues. However no solution yet.

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I can only recommend a bicep strap, which gives much better HR readings. Works with strength training, although it’s not at the wrist

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Thanks for the tip
But as I’ve already written in the post, a bicep band unfortunately doesn’t change the bad readings for me

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Ah, sorry I missed that. For me it works great, compared to a Polar H10 chest strap delivers very accurate results during strength training

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Just figured I’d share that after the most recent firmware update, 5/24/25 for me, my HR is tracking correctly during workouts :slight_smile:

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Are you sure? Did you compare with chest strap? Mine after update is the same, i think its just optical sensor… not possible to solve! doesn’t see spikes…
unless whoop make its own chest strap, i really surprise they didn’t do it yet… it’s kind of rare that algorithm is based on “wrong” data… crazy…

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I feel like it’s a little better. Before the update no HR above 120 was recorded. Now it goes up to 130, which is still way too low

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Yes I am sure! I have compared whoop on all possible locations against multiple Apple Watches, cardio machines and a chest strap. And whoop was the only device that wasn’t able to detect the peaks. It’s almost like if HR goes above 120, whoop just counts every other beat because it always drops to around 70-80 during the heavy working sets.

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I have exactly the same problem. I’ve owned a Whoop 5.0 for three days now.
Yesterday I completed my first cycling session on Zwift. The heart rate measurement was identical to that with a chest strap.
My first strength session today and the pulse on Whoop went up to a maximum of 115 beats. The Apple Whatch with chest strap displayed accurate values as usual.
If this is the reality of Whoop, then I am extremely disappointed after just 3 days.

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Seems like the reality.
I have exchanged tons of emails with support now. Dating back to a year ago with 4.0. I had the same problem, tried all the stuff I told above, got a replacement and still the same. Now that 5.0 came out I thought the sensors had to be upgraded and tried to give it another chance so I bit the apple and ordered an MG. Same story. Got back to talking with support and it seems like it is what it is and they’re just saying it’s the limitations of optical sensors in general, not just the whoop. Also after sending them proof that it is just the whoop.
And then after more complaining I just got sent a replacement of the MG. Today was the 2nd gym session and the problem is still there (who would’ve thought after all the backstory and extensive testing).

Let’s see what they’re answering now. But I think I’ll just get the same answer as before and get told to redo the same troubleshooting.

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Just out of curiosity I gave it a try today in a mainly body weight training and wore a Huawei GT Runner with OHR on the right an a Whoop 4.0 Biceps strap on the left and the values tracked where quite similar. Not that I want to say you do something wrong or that you don’t have tried everything, but at least here it seems to work quite ok

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I’ve been a Whoop user since the 2.0, and heart rate accuracy during weightlifting has been a persistent issue. Despite several updates improving HR tracking, it’s still unreliable for me. The biceps band isn’t a solution—wearing it on the wrist is necessary for the strength training feature to function properly. I’m cautiously hopeful the new hardware will finally address this, but after nearly eight years of waiting, my optimism is wearing thin.

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Even if they’re able to fix it with the new device. I am not sure, if I want to wait 4 years or even more for that
My membership is expiring by new year and I don’t think I’ll extend it, if the problem isn’t fixed until then.
I still think (or better hope) it’s a software problem that should be able to be solved

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Glad to hear it works for you!

I really couldn’t get it to work. Even with a bicep band.
I don’t know if that has to do with bodyweight/weight training. I can imagine that with weights the HR spikes a more drastic and spontaneous than with bodyweight with maybe more reps where the spikes take longer to accelerate or maybe it’s even blood flow restriction through muscle contractions or something like that.

Or maybe you’re just lucky, that the algorithm and sensors like your physiology :wink:

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You maybe right, that it’s a „personal“ thing. - I really tried many sportswatches from Garmin, Polar, Suuunto, Applewatches etc. and all of them worked quite ok on the wrist for me, while there were almost always other users, even one of my closer friends who had a hard time to get those same devices to work with their physiology. My friend looks like me, no tatoos, no dark skin, we had no idea what was the problem. It never worked reliably for him - but with watches he just used a HR strap for workouts and for everyday use, where there were no sudden spikes in HR the watches did ok on the wrist.
It would be really good, if Whoop would offer some kind of HR Belt integration for workout tracking - I wish you all the best, hopefully it works out somehow :+1:t2:

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I actually see no big difference in wearing the band on the wrist or the biceps (tried both). I think since you also could „track“ strength training sessions afterwards there seem to be some adaptations to the algorithm.

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