I have always wondered how to measure the calories expended during a training session (I practice Aikido, but this is a general question regardless of art or style) and I have found little advice on that.

My question: has anyone tried wearing one of the various fitness tracker armbands/bracelets/gizmos (like fitbit or any of the other models out there) for the whole duration of a lesson? I.E. warm-up, kata, kumite, randori, whatever your style does?

Any results? Do these things "recognize" movements outside of running/jogging/walking? I.e. assuming I tried one while doing Iaido, would the sword swings register at all, even if I am standing more or less in place? What about falls/throws? Has anyone tried this already? Results?

I am not so obsessed by the idea in itself to go out and buy one for myself, because even if I had one, I'd use it a few times during my Aikido practice to get a general idea, and for the rest of the time it would probably stay in a drawer... this is why I ask instead of actually trying myself.

UPDATE: a couple weeks ago (Jun 2022) I informed the other participants that I would wear an Apple Watch (Series 3) for the duration of the training. The results were ~300 Calories/Hour. The practice was not particularly strenuous but I think it is a bit on the low side. Maybe wearing it on the wrist does not provide the best results.

  • 1
    Found this: facebook.com/BlueLeafDojoAikido/posts/430595116987667 - we don't know how much the poster weights (and how "intense" their practice is) but at least it looks like it is somehow doable, the trick seems to be to use a Heart Monitor as suggested by Rob Gray, instead of a step counter.
    – p.marino
    Feb 24, 2015 at 15:10

12 Answers 12


I have worn my fitbit flex during warmup (purely accidental as I forgot to take it off when arriving at class). It doesn't give any sort of accurate reading of calories because it's only a pedometer and measures steps via arm swinging.

I've also worn a Garmin Edge 500 with heart rate monitor and tucked the Edge into my underpants (just don't fall on it). Tracking elevated HRM is probably more accurate for calculating calorific expenditure than a pedometer. From memory I burned about 350 cals in my 60 min Tae Kwon do class. I'm a 97kg male. To be honest I struggle to believe that I would burn 1000 calories in an hour of TKD. That's an hour worth of running at 10 km/hr, which is much more difficult for me.

  • Yes, the table above somehow does not look very convincing, at least for people over 70kg (and I already mentioned how some of the styles seems far off to me). On the other hand, I have experience only in Aikido, and I am no expert on sport medicine or calories expenditure... that's why I posted this question, actually.
    – p.marino
    Feb 24, 2015 at 15:00
  • I'm a boxer but 1000 calories per hour is pretty normal estimation. Your pulse goes up/down in a session and you barely rest. Sparring is also extremely hard. 6 x 3 minutes, with a minutes rest inbetween hitting near max pulse often burns a lot of calories.
    – cbll
    Aug 19, 2016 at 12:58

I would surmise that most of the fitbit type trackers will not work accurately enough for your purposes.

Most of these models rely either on accelerometers (devices that register the change in motion), or on GPS tracking/movement. I know from personal experience that even GPS watches that purport to sense treadmills based on hand movement are spotty at best, and I don't think the accelerometer would be much better.

If you want to have a better estimate, look at some of the calorie charts that are around that include various types of martial arts (Such as the one below).

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  • Thanks. But this is exactly the problem I have with charts: I have some problems believing that Aikido actually burns +35% more calories/hour than MMA. Also, I have trained for years with Iwama Ryu, and whenever I happen to work with Hombu-dojo people I had to work at a much faster pace while here everything is lumped together as "Aikido". I was hoping that a fitness tracker could be more "specific" and "reliable".
    – p.marino
    Feb 18, 2015 at 15:50
  • @p.marino - Unless you can find a lab that did actual analysis and published it, all of them are going to be estimates. Most of these (from my experience in exercise kinesiology) are pretty accurate to what I would expect, as you say the MMA is low, but I don't know what they are considering as MMA training. If I were to shift them, I would put an MMA class nearer to kickboxing or jiu jitsu (Depending on the type of class), and I'd have capioera closer to aikido. The rest is fairly close to what I would expect.
    – JohnP
    Feb 18, 2015 at 15:57
  • if you consider the value for Aikido "reasonable" I will be more than happy to use it for my own estimates, thanks.
    – p.marino
    Feb 18, 2015 at 17:57

I teach karate and wear the fitbit HR to measure heart rate.

I also use the polo loop with the heart rate sensor. I am 55 and my weight is 210 lbs (95 kg), been working out with weights for 30 years.

I burn about 750 to 1000 calories depending on sparring or not. Forms done with high power level can get my HR close to max.

So most of it depends on your intensity level. I hope that helps.


I have a FitBit Flex and wear it during Taekwondo for all activities except when sparring. No issues when hitting pads, but when I tried keeping it on while sparring it kept flying off. The readings are rough at best, because it only tracks steps via accelerometer.

I'd like to wear something during classes, but there's just too much contact to keep a band on for all activities. I've been eyeing the FitBit Surge for its heartrate and other tracking, but it's rather large and I'm not sure instructors - nor I - would be keen on me wearing it during any part of class. (Technically we're supposed to remove all forms of jewelry for class.) I'd use it for other activities, but I'm not sure that there's any device on the market that's ideal for martial arts given the impact risk.


I have used multiple different types of trackers to track my Krav Maga workouts. I am 45 and weigh 235 lbs. I have used a fitbit surge, Mio Alpha 2 (HR monitor), Polar with chest strap and a garmin with chest strap. I have found depending on intensity I burn between 300 calories (low intensity - avg HR 100) to as much as 1,000 calories during a 60 minute session (avg HR 150). It really depends on how intense the workout is. I track all of my workouts. We workout in a small dojo so I can use a bluetooth chest strap and if my phone is in the same room or a sportwatch like the Polar M400 or Garmin Vivoactive it will send the data to the device and you can review it when you are done. That way it won't be on your wrist to accidently hit someone. Another great device is a schosche ryhthm plus + armband heart rate monitor. It can send the data to a smartphone or sport watch with a 100-foot range. I have tested most of these and can tell you the chest strap is the most accurate followed by the mio products and the schosche rythm plus. The surge doesn't pick up large arm movements very well but it does a decent job. It's usually 10-25 bpm lower than other heart rate monitors for boxing/krav maga. Let me know if you need any additional info.


  • Is it possible to wear a Bluetooth chest strap monitor with the sensor on the back - to avoid the possibility that an opponent's supposedly non-contact blow isn't non-contact, and lands on the sensor?
    – Monty Wild
    Dec 7, 2015 at 1:02
  • I'm want to find something I can wear at Krav, but we have very heavy contact so I wouldn't trust anything too exposed. Anything on the wrist would be torn off, chest monitors too I think would go (shirts get torn frequently so surely a chest strap would end up getting ripped off). Ideally I could wear something on my groin under my box - that's probably the best protected place. How did you go at krav with sparring / scenarios? Was there much impact on the monitors?
    – jsj
    Apr 8, 2016 at 3:26

I am currently using the withings pulse o2 for aikido. I put the module under my obi. I haven't used it for long enough to have a full opinion.

It is possible to clip it to clothing, which is the best way I have found to use a tracker for aikido training.


I purchased a Microsoft Band about the time they came to market because I wanted a HR monitor and didn't want to deal with straps and because I felt that it was unobtrusive. It has an exercise mode and occasionally I would put it in mode before my TKD class. Microsoft's app provides a range on their graph for viewing your HR data, as I was trying to remain in a MODERATE area. I found it to be reasonably accurate for my purposes, which meant that I needed to turn down the intensity levels often.

I no longer use the HR monitor but I still wear the band daily for step counting and for text, etc notifications.

I never found I had any problems wearing it during MOST activities during class; I don't think I've worn it during sparring but it might be feasible but at risk to the device and the wearers wrists.


I teach/practice Isshinryu. It tracks your activity; it throws off the actual counting of steps since it will count each punch as a step or two. With that said it recently died since it failed to charge the battery. Possibly due to the excessive forces generated by the punches. I do remove my flex during sparring to prevent it from being struck or injuring someone. Fitbit is sending a replacement; I might be more careful with the new one since I enjoy using it.

  • It would be helpful to be more specific about the tracker you're using.
    – Mike P
    Jan 15, 2016 at 16:27

I train Thai, mma and bjj and I use a garmin vivoactive hr, you can use it with or without a chest strap I have used it for heart rate with just the watch and just put it a few inches higher up my arm just after my hand wraps. The glove covers it, I've even used it during sparring (45 minutes averaging 194bpm!) and so far it's been accurate, for bjj I use a chest strap and same with wrestling. I'm pretty happy with it. You need to buy the strap seperate and I'd go with the flattest garmin strap you can find. It's also perfect for when I'm doing my s&c work, it's got all the gps features you could ever need and I use it when I swim. Can't rate it highly enough! Another handy feature is that you can connect it to my fitness pal and track your diet via that, fantastic when cutting weight. It adjusts the calories in/out but don't input your exercise on the my fitnesspal If it's tracked via the watch but if you take the watch off for the session you can put it in that way and it will adjust your calories via an estimated amount for that sport. And it links in to the apple fitness app too, never used it but I'm sure that's good too.


I wore my charge hr in a 3 hr session of Iaido. I burnt about 1000 calories. Bear in mind that iaido is not that intense as in comparison to other arts I have done (I burn the same calories doing a 40mm insanity vid). What was interesting was how heart rate changed throughout the session. Obviously during individual warm up my heart rate got up high. I like to use the insanity warm up plus press ups and squats followed by stretching.

The next part of training was to complete 100 kata in an hour. Bear in mind at the time I only practised seitei (12 forms) just over 8 times through. Heart rate was at medium high cardio rate, but I burnt more calories than I thought I would. The last hour was our own practice which was slower but a lot more stressful on the legs and I feel a better workout. The tracker read that this was the least productive for the health parameters, but to me it was harder on both body and mind.

I have worn trackers for taichi, silat, general fighting exercises, and others. To be honest trackers are great for staying fit, but as for collecting data for MA well as every session is different and most classes won't allow the wearing of any jewelry or accessories I don't feel the need. I mainly use for weights, cardio and hiit.

  • So, do you feel it did a good or a bad job at tracking? Jan 3, 2017 at 14:03

I practice Krav Maga here in Brazil and I have a Fenix 6 sapphire. Yesterday I got a HRM PRO and used it during class. It tracked my steps and heart rate. I Wonder wich Activity should I set on my watch to best register my workout data at KM practice. HRM PRO can be used stand alone af sych after class. Ano suggestion? Tks.

  • Please understand that I am not trying to make fun of your practice: if there is no "Martial Art" setting I'd suggest to try "Dance" instead.
    – p.marino
    Jun 30, 2022 at 9:47
  • There is Mixed Martial Arts activity Mar 19 at 13:22

I've been using the Polar M400 (in my underpants) with the chest monitor. 2.25 hrs of intense karate = 1300 kcal for me (220 lbs Bwt). Just been told I can't wear a chest monitor either so looking for a Polar alternative if indeed one exists.

  • 2
    Please take the tour. It is hard to tell whether your post is really an answer to the question; it reads partly as an answer but ends with a question.
    – mattm
    Jun 6, 2017 at 3:22

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