Basis and heart rate monitoring

Posted on Apr 11, 2013 in Gadgets, Health and Fitness

Basis watch worn on my arm

I wrote a review of my Basis monitor after having used it for 6 weeks. After having used it for more than three months, I still like it but now I’ve discovered a huge glitch in it: the heart rate monitoring. In short: Basis heart rate monitoring is very inaccurate, essentially showing and recording wrong data or no data at all as soon as you move around.

I discovered it quite early on when looking at the “data details” view. Here’s a screenshot:

Screenshot of heart rate details view from my Basis data

Each dot means that Basis has a data sample. As you can see, the data samples are fewer – in some cases non-existant – at certain points. These points have one thing in common: I’m not sitting still or lying down. In the morning I take a 40 minute walk to work. The middle of the day was lunch. I left work at 6 to take a Bodycombat class, then I walked home. This means that Basis only has fairly accurate data for when my pulse is low and I’m being still.

I decided to put the Basis to the test. I have a Polar FT80, which uses a chest strap to monitor your heart rate (Basis actually monitors your pulse, which is a result of your heart rate, while Polar monitors the electric impulses created by the heart). I used it to see how the Basis monitor compared in three scenarios:

1) Aerobic exercise (in my case, a Bodycombat class)
2) Weight lifting (in my case, a Bodypump class)
3) Moving around (in my case walking to the gym)

Here’s a breakdown of the data:

Aerobic exercise 

Polar FT 80 graph of my heart rate for a Bodycombat class

This is the graph of my heart rate during a Bodycombat class, as recorded by the Polar FT80.

Heart rate data from my Basis during a Bodycombat class

A graph of my heart rate during a Bodycombat class, as captured by Basis.

According to my Polar monitor, my heart rate averaged 157 and maxed out at 179 during that hour. The Basis monitor failed to log enough data to create a graph, and it recorded a high of 148 (lower than my average heart rate for that hour) and an average of 116. At least it got the calories somewhat right: 802 to my FT80′s 1058.

Weight lifting

The graph of my heart rate for a Bodypump class, recorded by a Polar FT80

The graph of my heart rate during a Bodypump class, recorded by the Polar FT80.

Graph of my heart rate during a Bodypump class, captured by Basis

Graph of my heart rate during a Bodypump class, as captured by Basis. (Green staples are calories)

Again, the pictures look different. I do get a pretty high heart rate during a Bodypump class, due to loading up the bar; the Polar monitor shows an average heart rate of 137 and a high of 169. The Basis: high of 138 and average of 107. If we look at the calories, my Polar FT80 reports 706 calories, the Basis monitor 251 (and since the Basis cannot zoom in on 60 minutes it’s actually showing the count for 75, 15 minutes longer than the Polar)

Brisk walk

Graph of heart rate data from a brisk walk, recorded by a Polar FT80

A heart rate graph from a brisk walk, recorded by my Polar monitor

Heart rate data from the Basis monitor for a brisk walk

Graph of my heart rate during the same walk recorded by the Basis

This walk was 3,2 kilometers (2 miles) and took 45 minutes – a pace of 4 miles per hour. It’s a brisk walk, but nothing extraordinary. And yet the Basis fails: it shows a high of 141 (the Polar gives 122) and an average of 85 (the Polar says 100). The calorie count for the Basis was about 200, while the Polar said 299.

Once I realized how bad the Basis was at recording heart rate whenever I’m not sitting or lying down, I decided to do another test: check how accurately it displays the current heart rate. I wore my Polar FT80 for a whole day, and checked my heart rate on both monitors at random times, and I wrote down what I was doing at that time. Here’s the graph:

Graph of heart rate during a regular day, recorded with Basis Monitor and Polar FT80

The blue line shows the data from the Polar monitor, the red from the Basis monitor

(Note: when standing and walking, I waited a couple minutes before checking the monitors, as to give the Basis monitor a chance to catch up and eliminate any lag.)

It turns out that the Basis displays an inaccurate heart rate whenever I’m doing anything else than sitting down.


Basis did address the heart rate monitoring in a blog post in November 2012 (before the first units had shipped). However, I don’t think that that blog post is honest about how bad the Basis is at recording your heart rate. It basically displays one thing right: your heart rate when you sleep, and sit.

The bigger problem is that Basis’ poor heart rate monitoring also affects the calorie count. If you look at the calories burned during my walk, Basis says 200 calories when the actual number was 50% higher (the Polar FT80 is accurate, because it uses VO2max in addition to sex, age, weight and height). During the aerobic exercise the Basis monitor showed 800 calories, when the actual number was more than 30% higher. The weight lifting was the most incorrect calorie measure; Basis says 251 when the actual result was 180% higher. The reason the Basis did better for aerobic exercise is that you move your arms a lot in Bodycombat, while you move them less in Bodypump – so the higher calorie consumption comes from the accelerometers, not from the heart rate monitor.

Even once Basis opens their API, you can’t do much with the heart rate data except for the resting heart rate. Considering that they still cannot take any new orders, and devices like Amiigo soon coming out I’m changing my recommendation: don’t wait for the Basis. A second generation has potential, but the first is not worth the money.

I’ve been comparing the Fitbit One, Nike Fuelband, Jawbone Up, Basis and Bodymedia when it comes to calorie consumption and sleep, and will return with a summary of which of these devices are accurate and which are not.

  • Dave Haupert

    I was hoping you or someone would do this. Sadly, when I saw an interview with the founder, he said that this was not targeted for active people but for sedentary people who want to become more active through small steps. To me that seemed silly- a product like this is (in theory) perfect for fitness enthusiasts, and those are the ones that have been proven to spend money, time, and energy on this very topic. Why try to invent a product for people who have little or no interest in fitness related activities- while it seems like a great ideal, the reality is that they won’t be buying your product! I now am thinking that based on this, the actual data is not accurate for fitness activities of any kind so that’s why they are going with the sedentary folk- they are the only ones the technology works with any degree of accuracy!

    I had high hopes for this product (and it’s how I found your blog a few months back!) and hope that they may be able to fix these issues, but I’m wondering if the wrist is just not an accurate place to read the pulse.

    I’m anxious to see what you find with the bodymedia as it seems like it has the most potential for tracking this data with some accuracy. Thanks for doing this!

    • Micke Kazarnowicz

      I think they might be able to address some of these issues with firmware updates, but to be honest, I think that it won’t be until the second generation that Basis will become really useful. And by then, someone else might have released a great self-tracker.

    • Sean Coulton

      I completely agree! As a competitive cyclist, I am obviously not the target audience for Basis. This is a sad fact, because when I first heard of the product, I thought this would be a great way to monitor my numbers off the bike, and my off bike, day-to-day recovery. I also loved the idea of it over a lot of other devices like the fitbit, because it seemed like it would be more useful to someone like myself that is not primarily a runner and needs more data then step a simple step counter. However when I see this comparison of heart-rate data, I think it falls flat on its face for usefulness (at least for an athlete) and in spite of having the money to spend on the Basis and a reservation spot to order, your comparison Digital McGyver has helped me realize it is sadly, probably not for me.

      • Micke Kazarnowicz

        Thanks you for your kind words, Sean!

  • Christopher Regan

    I’d also agree with your findings as I use a MotoActv as well. Consistently the Basis is at least 20% off, on the low side of calories burned, compared to the MotoActv. I enjoy wearing it but I could definitely seeing it being more useful for people who aren’t super active. It would at least give them data on how many calories they are burning.

    • Micke Kazarnowicz

      I agree. The problem as I see it is that Basis aren’t honest about how inaccurate the heart rate monitor is.

  • Grace

    Does it still function adequately as a pedometer and other stuff? I’m one of those sedentary people — because of a heart problem I have to keep my heart below 115bpm at all times. I’d really like to use the Basis to help measure my activity (in conjunction with a more accurate HRM). I was thinking of a FitBit, but it’s the same price and seems less convenient. What’s the interface and web app like?

    • Micke Kazarnowicz

      It does. I would look at the Jawbone UP and the Fitbit. They’re just as good at tracking your activity and cheaper – the Jawbone is $129 and the Fitbit is $99, while the Basis ist $199. The other monitors that the Basis has are either inaccurate (like the heart rate monitor – you can’t trust what it displays when you’re walking) or not used to measure anything (skin temperature and perspiration) yet. So until the Basis team finish this product, I’d recommend Fitbit or Jawbone UP.

      • Grace

        Thanks for the suggestion! And thank you for the great articles on all the Basis – yours are the most in-depth articles I’ve found so far (and I’ve been looking at it since way before it came out!).

      • Grace

        The one thing I would really like is a device that warns me when I’m about to reach a certain step/activity count. I have to limit the amount I move each day because of my illness. I’ve been using a (fairly inaccurate) wrist pedometer to do that, and I really liked the way I could just look down and check my steps. But something that buzzed or beeped a warning would be so handy. It’s a shame there’s nothing like that available.

        Anyway, I’d probably prefer the FitBit to the Jawbone UP because at least you can look at your step count on the FitBit. The Basis looks good in that respect too – and it sits on your wrist, which makes it much easier to check and less fiddly than the FitBit

        Do you think that FitBit or Basis has a better web interface? Which one is more usable for that?

        • Micke Kazarnowicz

          I think Fitbit is simpler from what you’re describing. The Basis will show you more information and has additional features that take focus from what you’re interested in. And if you have a smartphone, the Fitbit now syncs to both iPhone and Android wirelessly, so you could keep track that way. The Jawbone is not as simple, as it doesn’t have a display and you need to sync it to see the amount of steps.

  • Binaryoverload

    Did you have it on tight enough, I run all the time with my Basis and it
    always records data, it may not necessary be as accurate as a chest monitor but
    it collects data that I find to be fairly accurate but your results look like it was not even recording data.

    • Micke Kazarnowicz

      I can’t wear it much tighter than I’m wearing it – it’s tight enough to leave marks when i take it off.

  • DannyClover

    Hello – How do you make the graphs with the FT80? Are those from the polar website or are you able to capture the data and make your own graphs?

    • Micke Kazarnowicz

      Yeah, gives you those graphs when you sync your monitor using their Web Sync software.

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