HRV, Sleep, Calorie tracking; devices from Whoop to Oura - any others? Join in!

@Pierre Welcome to the fold!

That is a nice discount for six-months. I don’t think that was running back in May. I used the rational that I am using the money I would spend on gas and tolls driving to the office. I think I have also used that money to buy a new helmet, a jersey, a couple pair of socks… oh, well.

I think near the end of the subscription you just renew/ extend. These are version three of the hardware. The firmware has been updated a couple of times since May so I think you will just keep what you have.

I do not have experience with wearing on the upper arm but I have been considering trying it. I started wearing a watch when I was 12. It got to the point I felt naked without it. It was more noticeable to me to go with out something on my wrist than wearing my wedding ring (my wife notices that of course!).

So, once we were all working from home I stopped wearing my watch. The Whoop has replaced it. But I can see some possible advantage to wearing on the upper arm especially while sleeping. Let me know if you try.

I am starting to look at HR and calorie burn comparisons across the various platforms I use. Will post my findings in the coming days.

I am interested to hear about your experiences.


I am very interested in the results of this!

Will write more soon. Need to get some shut eye. :slight_smile:


@Pierre @Martin I have started my initial analysis just comparing the Whoop to my Element Bolt (using Tickr for HR) and the short analysis leaves me to believe the Element over-reports calories. On one day my cycling effort on the Element was nearly as much as that reported for 24-hours on Whoop. Average and Peak HR for same activities were close but rarely identical which is probably explainable through measurement variations. I want to build out more than a weeks worth workouts but I will share my spreadsheet. To its credit, Wahoo does post how they calculate calorie burn on their website. Will see if Whoop shares.

More to come.

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Quick update: I got my Whoop today. Initial impression is pretty positive. I need more time…

What’s up with teams? Should we create one? Sufferfest-Team anyone?


I am on on-board with a Sufferfest-team! Great idea.

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I’m a WHOOP user for nearly a year.
I mostly use it to monitor my sleep, which have been a eyeopener, how much proper sleeping hygiejne can improve sleep and by that recovery. It’s also good to monitor RHR and strain.
For me, the advice on how much strain will be optional for the Day is a good feature.
:+1: for the SUF team on WHOOP .


Just here to mention “oura ring”. It does all these things and you don’t have a monthly subscription or have to deal with potentially ‘two watch-like things’. I have an Apple Watch, and so my obvious choice has been the oura ring.

It is quite accurate and it has been really helpful to enforce good bedtime, and to not discount life stresses and their impact on my body. (I work an on-call shift approx every 6 weeks which kills my readiness).


Dame @emily … now that you’ve been using that a while, what’s your instincts on the ring for HRV then? Accuracy you commented on… have you (just in case) been able to compare with anything else?

I ask as I find HRV generally not that reliable (yet) despite two dedicated devices in the past and now on an iPhone.

Do you find it ‘backs up’ how you ‘feel’ ?

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@Martin - yes. I am pretty good at ignoring body signals, which is a problem. Looking at these numbers, keeps me ‘honest’. I was using HRV4training for a while. I was also using a separate sleep monitor. HRV4Training - I would often discount the results as inaccurate and imprecise - so I largely ignored them.

I think the sleep cycle thing is much better. Like ‘why did I stay in bed so long but feel like crap?’ … now I have data. Like - I can see my elevated HR, I can see my lower HRV, and I often also see a lack of REM and deep sleep. On those kind of days, I am not about to break any personal records and I might choose to take it easier. That is quite a lot of progress for me.

HRV generally tracks with training load … but also stress. That is nice to see as well. The value it takes seems to be the average during your sleep.

Fun note: oncall can mess me up so much - that I am not recovered for days after it is done sometimes - that is also data I did not have prior to having a dedicated HRV/sleep tracker thing. I am much kinder to myself now.


Nice update - thanks.
And that’s a good call on the shifts thing having an impact that you can now quantify. It’s very easy to be too hard on ourselves !!
I’ll maybe keep an eye on offers as time goes by.
Can’t afford subscriptions models like some of them but one off is easier


Sufferfest Team Code: COMM-1D8884

For anybody who would like to join.


I did my first SUF workout while wearing whoop this morning and I encountered a pretty big difference in reported calories.

SUF App: Has power from a Kickr Bike and HR from a Garmin chest strap. 416 Calories.
Whoop App: Has only HR from the whoop band. 236 calories.

That’s a pretty big difference. In the past, I recorded on garmin with a similar hr-only-setup - and the values always came pretty close to the Sufferfest numbers.

I want to trust the SUF numbers more and will keep an eye on future developments. Big workouts are planned for the weekend.


As I remember calories using maxhr… Is it correct?

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There’s an interesting podcast about how WHOOP calculates calories burnt, and how this is very difficult to do anyway:

Personally, I don’t trust kcal computations based solely on HR at all. If you have a power meter, computing the energy spent from power data tends to be more robust because you have less values for which you have to rely on generic formulas (basal metabolic rate and efficiency).

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@lifeintheslow @Pierre @Fast Thanks for posting on the podcast. I will check it out.

There are any number of articles online regarding the challenges related to calculating calories. This older article from Wired compares a number of fitness trackers -

It refers to Wahoo’s calculation and at that time they were the only ones to publish their algorithm which is on their website -

I guess I generally take them with a grain of salt. It does backup what I have read in other forums that just because it says you burned 1,000 calories doesn’t mean you can or should eat an additional 1,000 calories. Limit it to 10-20% of that number if taking in extra.

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@Rick66 thanks for sharing Wahoo’s formula, that’s interesting! My takeway from all of these discussions is that all of those metrics (out and in) give you an indication of where your energy balance roughly is. It still makes total sense to watch those numbers, but it’s important to keep that in mind.


I get what all of you are saying, but the fact is, as soon as you throw a power meter in the mix the guessing game becomes pure measuring by physical laws, and therefore the readings should be much more accurate. Like I said in the previous post, my Kickr Bike connected to SUF produce pretty believable results.

Basing calories on HR alone is tricky, yes, but Garmin and their Firstbeat technology always got very close to the numbers produced by the power meter.
In this regard, after only one workout logged, I am a bit disappointed by whoop.
Even a rough online calculator (fed only with body measurements and time) reports calories better, in my opinion. I am open to change my mind after further testing…

In my first example whoop is off by 56%!

In the last year, I successfully lost weight by using calorie counting. Yes, whoop, is right that sometimes there can be up to 20% margin of error. I still managed to predict my weight lost very accurately through all the month by using simple math. Even with eating back the exercise calories. In my experience the margin of error is - most of the time - much smaller.


I totally agree. Keeping track of your intake and matching it to your output makes total sense, even if the measurements of both are not perfect.

I never looked too closely at the numbers WHOOP generates, but I’ll go through my data to check.

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Yes, please. I am very interested in this.

I think @Rick66 is also due for a short comparison of the reported calorie count on his side of things. :wink:


@Pierre Did a quick check with a handful of rides and compared the Whoop data with the values generated by my Wahoo Elemnt (with a powermeter).

I checked 7 recent rides with energy output between 377 kcal and 5.365 kcal (no typo). Whoop tends to underestimate kcals ~10%, but one ride was overestimated with a 46% larger output compared to the Wahoo, and one ride was underestimated with a difference of 33%.

Depending on the formula Whoop is using to derive calorie usage from HR, it might make sense that it tends to underestimate actual output for a reasonably trained cyclist.