WHOOP 4.0 – Finally! Is it worth it? Does improved accuracy entice you?

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Recommended: Whoop Band Review

WHOOP 4.0 shipping to customers – should you re-join? or join for the first time?

Freebie: Free WHOOP 4.0 Band + a month free subscription HERE

Yes, really!

WHOOP 4.0 has already started shipping to some lucky customers who were quick to order their free band upgrade on the day of its announcement. Like many of you, mine is still en route somewhere from China to my house via who knows where. Good things come to those who wait.

WHOOP’s app has already been updated and those of us still on Band 3.0 can see various screens and metrics that just have blank data for us now. So, at least we have an idea of the goodness to come. But what about those of you who may have held off jumping onboard with WHOOP and are now intrigued by new claims of accuracy? Is 2021 a sensible year to go-WHOOP?

Probably. Maybe. Is the answer. Here’s why.


WHOOP 4.0 – Is it worth it?

WHOOP’s premise has always been awesome and I remain staggered that no other sports tech company has made a serious effort to compete directly with it. What is a unique product worth?

WHOOP 4.0 – A Re-Explainer

Simply put, WHOOP is an Athlete’s Physiology Tracker.

It tracks your exertions, recoveries and sleeps via a heart rate sensor and other sensors. One of its key selling points is the form factor. Ie it’s a comfortable, customisable and stylish band that can be worn 24×7 for several days. On the whole, it’s a wear-and-forget device that doesn’t have the physical intrusion of a bulky watch. As well as tracking you it also coaches you on how long to recover for, what your recovery state is, how much sleep you need and more besides. There are some pretty cool analytical reports too if that’s your thing although I love using the great app.

WHOOP is less good when you need instant numeric feedback for your sport. So, if you are a runner or cyclist who wants to know their exact performance stats during a workout you won’t get it. There’s no screen to tell you your speed, power and so on. It’s not designed to do that. That’s when you need something like a watch.

Thus, if you are a team sports player, WHOOP is a great tool, with the caveat that you will need to wear it on your upper arm in contact sports. Halfway through a game, how many footballers look at their running on a watch?…A: none.

Future View: With WHOOP’s acquisition of PUSH we can expect a market-leading WHOOP ecosystem for lifters, providing they get the accuracy right.

Accuracy Again

WHOOP’s historic mistake was to respond to customer demand to broadcast heart rate so that gym equipment could display it. Naturally, this meant that people like me (sports tech testers/reviewers) could now precisely compare its accuracy to medical-grade chest straps. Clearly, it’s not as good as a Polar H10! But then neither are all other wrist-based optical heart rate monitors as results vary considerably between people and depending on how they use the technology. For example, here’s the latest, greatest Garmin Fenix 6 Pro, whose green heart rate line looks great….until it doesn’t. It’s wrong.


Contrast that to these two recent runs where I wore WHOOP 3.0 on my wrist where it gives better results than Garmin in one but not as good results compared to the Garmin chest strap in the second. This data is all mostly fine but the point is that what you get with Whoop or Garmin could be better or worse than what I get. It really is an individual thing.


For my steady-state training, Whoop 3 is sufficiently accurate to give meaningful and actionable results. For some people, it’s not. Same with Garmin, Polar, Fitbit, Apple.

But, I tend not to do much gym work and that is the area where all wrist-based optical HR tech struggles.

That said, WHOOP4.0 claims to be more accurate than the 3rd Generation Whoop strap I’m wearing right now. This will likely mean that the tracks it produces during workouts will be smoother especially if you wear it on your bicep and hopefully more people will get more accurate tracks. So, if accuracy had previously put you off, it might now be a time to think again.

There were also some concerns about how Whoop assessed sleep recovery. Since August, this is now calculated in one of the two ‘correct’ ways.

Edit: In the absence of my own Whoop I’ve been scouring the net for feedback on the accuracy of the new Band 4.0. Stories are definitely MIXED, and here is a chart from @r/rearviewmirror1 who seems happy with this performance. To me, it looks like the same performance as I typically get with Band 3 (fine for overall load purposes,  less so for instant HR).

Credit: r/rearviewmirror1

Whoop 4.0 – What Else will convince me?

My bug-bear with Whoop has always been the strap’s hinge mechanism which periodically comes apart. Sure, Whoop would replace it if it broke, it’s just mildly annoying. Whoop 4.0 has a new strap mechanism and hopefully an improved charger that more snugly fits the Whoop.

Other than that it might be the new sensors that convince you. I’ve already been seeing respiratory rate for some time on the app and Whoop 4 adds SpO2 (blood oxygen) and skin temperature. Neither of those is interesting to me in themselves, probably nor to you either. However, they can both be used to improve the accuracy of sleep tracking and recovery.



The WHOOP 4.0 strap is totally changed in all key respects and alongside that, we see a new apparel range that allows WHOOP 4.0 to be worn in a variety of places on the body.

The key takeaways are innovative new tech that is hopefully accurate plus some sports clothing.

when is whoop shipping?
Here are the new details

  • 33% Smaller: WHOOP 4.0 is 33% smaller than WHOOP 3.0 and claims an improved 4 to 5-day battery life
  • new Optical Heart Rate Sensor: The sensor has 5 LEDs (three green, one red, and one infrared) and 4 photodiodes. Couple that with WHOOP’s algorithms and WHOOP claims its accuracy is validated by 3rd party testing.
  • Next-Gen Battery: Earlier this year, Sila Nanotech received a huge investment to support the R&D of their new battery that uses silicon-based anodes for the first time in a Li-ion battery. This tech will probably make its way into electric vehicles but WHOOP gets to use it for the first time in their product. The key benefit is that there is a 17% space-saving or, put another way, this almost boosts 4-day battery life to 5-day battery life. Industry players Garmin, Apple and Samsung must be eying this eagerly.
  • Battery Pack 4.0: There’s a newly designed battery pack that can charge on the go as well as respond to a tap to show the charge level
  • Sleep Coach + Haptic Alerts: Gentle vibrations can wake you up at the right stage of your sleep cycle.
  • Pulse Oximeter: Supports blood oxygen calculations (SPO2) to offer new physiology insights
  • Skin Temperature Sensor: Temperature is another new metric that can be used to improve health/illness features, menstruation monitoring and sleep stage calculations.
  • Health Monitor: Track live heart rate, skin temperature, SpO2, resting heart rate (HRrest), heart rate variability (HRV), and respiratory rate in one view. Copy 30-day or 180-day trends of these metrics to your coach, trainer, PT, or physician
  • IP68 & Waterproof to 10m – hmmm. Don’t dive in!
  • BLE Support – ANT+ not supported. It’s a Bluetooth Low Energy/SMART sensor.

WHOOP 4.0 Accuracy Results – GYM Results & Wrist-Worn | FitGearHunter

WHOOP’s Any-Wear clothing range has pouches into which the WHOOP sensor easily slips and reads data from your torso, waist, or calf. The clothing collection includes sports bras, compression tops, leggings, shorts, and athletic boxers which vary in price from $54 to $109.

  • Fast Link Slider: This allows bands to be more easily removed, swapped and then for the sensor to be placed in the clothing if desired.
  • SuperKnit & HydroKnit Bands: Respectively these are for comfort/durability and a fast-drying version for sport
  • Any-Wear Detection: The clothing and WHOOP interact so that WHOOP records the wear-position.


Who Gets a Free Upgrade?

I’ve already successfully completed the upgrade request process – it works.

Existing subscribers can register for the new WHOOP 4.0 and get a free upgrade sent to them later this month.

If you are a founder member it’s different. You should find that your existing WHOOP 3.0 membership is now deactivated in the app. You will need to upgrade to the subscription service and provide valid credit card details. I guess that isn’t what you originally signed up for when you bought your original WHOOP outright but it is what it is. As a sweetener WHOOP gives you free 2-year membership until September 2023. You can upgrade online or through your app where the screen should look like this.

when is whoop shipping?
Reserve yours or subscribe: Whoop.com


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19 thoughts on “WHOOP 4.0 – Finally! Is it worth it? Does improved accuracy entice you?

  1. Same here. Been seeing 5-7 weeks for the past 4 weeks (it was 6-9 weeks before that). I pre-ordered mine immediately after the announcement.

    At this rate, I don’t think I’m gonna see the new strap until after Christmas, which means I lose upward of 3 “free” months out of the 2 years given to us, founding members, on upgrade. Not the end of the world, but it is still about $70 value. They could have thrown a free band or two for the wait instead of charging extra.

    1. i’m hoping they take that into account if enough people complain. at the time of the announcemnet there was zero customer service, i think they were overwhelmed. however i managed to get them to help to combine my two separate orders into one and then remove the shipping on one…point being ask and see what they say

      1. I’ve been running Polar and WHOOP side by side for the past several weeks, and honestly — as I said in another comment — if not for Polar’s occasional inability to correctly identify beginning of sleep and hence recovery analysis window, I’d no longer be waiting for WHOOP.

        Most of the time, their sleep tracking and recovery scores are pretty aligned, and when they diverge it’s because Polar gives far more weight to your sleep — not just duration, but quality of sleep — while WHOOP to this day is basically HRV based. If they look at sleep at all, it’s just duration compared to your sleep need.

        And so I’m starting to ask myself if several failed sleep/recovery days per month from Polar justify $24/month cost of keeping WHOOP down the line.

        1. Yes this is true, Polar has all the algorithms and OHR hardware and easily could launch subscription based service like WHOOP did and make tons of money, but the problem is that Polar lost its creativity and agility somewhere on the way. I am also using Nightly Recharge (especially ANS) to track my recovery, but I believe WHOOP will progressing much faster than Polar.

  2. This! This is the question. 3.0 is totally inaccurate (likely horribly) on the wrist for anything non steady state, especially activities like CrossFit which it is sold for! The improved accuracy AND the new band removal were key aspects so you can put it on your bicep for best chances. I think the accuracy bit for workouts is the fundamental area of change they’ve had to make. Great article!

  3. Moved recently to iOS and have been testing 2 apps: Athlytic and Chipr.

    Basically they collect whatever data is available in Apple Health and calculate Recovery, Exertion, Sleep, etc. They even look like Whoop!

    You just need a way of having the data in place but you don’t need an Apple Watch, I’m using a Garmin 24/7 and do a 1m morning HRV reading with HRV4training. But for the price of Whoop you could get a “free” Apple Watch after a year…

    Athlytic (around 25 bucks a year, free trial available)
    Chipr (free no strings attached)

    The only thing that seems missing is the journal type thing, so you don’t have correlations/insights going this route. It seems it’s a one man show for both apps, but the developers appear to be active and receptive to user feedback.

    Anyway all this just to say that you could track recovery/strain TODAY, without having for Whoop to arrive.

  4. I just can’t look beyond the price. I compare that cost to all the other stuff I spend on running and cycling and the cost/benefit doesn’t stack up for me.
    Also, having used HRV before, I just find that I’m not very flexible with my training. I have my plan and I generally stick to it. A bad HRV either confirmed what I felt in myself, or wasn’t so bad that I changed my training.
    But I’ll still read Whoop v4 reviews with interest. Never say never.

    1. There is certainly alternative tech that can give you similar data. As mentioned above it’s best suited for team sports, maybe also to x-fit type training if the new sensor can handle the body movements/data noise from that type of training

  5. Having used whoop 3 for past 3 months I find all data interesting and some relevance on short time activity’s. I try to play golf in competition and was really keen to see my stress levels, pulse at critical times thru the round. Unfortunately the data on pulse/ stress is not logged at small time intervals , like exact time in minutes. This makes alignment to stress situation double bogey, or out of bounds with what my pulse, temp etc at that exact time impossible. They need to tighten up the time line on the graph so golfers can correlate stress with actual activity. Looking forward to free 4.0 when it arrives?

  6. If you check Reddit you will find that the majority of the users who have received their 4.0 are having terrible issues with it, some of them rendering the entire device unusable.

    In addition to that, the accuracy of the sensors doesn‘t seem to have improved at all, as the whoop was off by quite a bit when compared to Polar H10 for example.

    All of this has been an absolute mess of a rollout, with recent order updates from an hour ago literally doubling shipping times for most people. Not a single apology was given by whoop either, and needless to say I have now cancelled my order (which went up to 10-12 weeks wait time as of today).


    1. oh dear.
      I did get a new communication today and know someone else who has progressed up the queue.
      I guess y ou tend to only hear about people who are having hte problems on the help forums

  7. Ugh. That’s so upsetting to hear about the sensor.

    And I can confirm the same thing about shipping. I ordered it in two separate ways and one of them says they are shipping within the next few days, and the other changed to 7 to 9 weeks! They were both ordered on the same day

  8. Received this email from WHOOP and my estimated shipping date was moved to 11 weeks 🙂 :

    We are writing with an update on your recent WHOOP 4.0 order.

    While we have worked extensively to keep pace with the overwhelming demand for WHOOP 4.0, in light of global supply chain disruptions, orders and upgrades are taking longer to fulfill than originally anticipated. While this is not the experience we want to provide at WHOOP, we are doing everything we can to get your order out as quickly as possible.

    To increase transparency about your order status, we have resumed regular updates to the Order Status page. Many of you will be excited to see that your WHOOP is shipping very soon. For others, the wait is longer than we anticipated. This status is an estimate and is updated to reflect the most current information we have available. Our teams are working around the clock to speed up our production process and shorten fulfillment times. Once your order leaves the warehouse, you will receive a separate shipping confirmation email with tracking details.

    Thank you for being part of the WHOOP community as we work through the challenges posed by global supply chain disruptions.

  9. The Whoop 4.0 Rollout has been an astounding failure. The few that have received a band are plagued by battery issues that Mae the band unusable. Others have had massive delays which I can only guess are now related to a serious hardware issue. Why aren’t more sites covering this failure

    1. It def needs to be talked about – it’s been rough. If the sensor turns out to be garbage I plan to be harsh.

  10. Hello,
    I got a question. Do I have to carry my cell phone with me all the time in order to get the data for analysis?

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