The Bodybugg/GoWear Fit
I’ve always loved training related gadgets and hope to look at some of those over the coming months in future articles. While most of what I’ve been interested in related to training (e.g. heart rate monitors or what have you) some gadgets help with fat loss and body recomposition. Digital scales and such are part and parcel of many people’s diets of course but here I’m talking about slightly higher tech-stuff.
And today I want to look at something that, while not exactly ‘new’ (it’s been around for a few years at least) certainly has a lot of interest and questions about it. And that is the Bodybugg/GoWearFit. Now strictly speaking, both of these devices are different, but they are both made by the same company. And are essentially the same device. So far as I can tell the biggest difference is that the GoWearFit (hereafter GWF) uses slightly different software than the Bodybugg but, for all practical purposes, I’m going to consider them the same device. This is what it looks like.
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The device is worn on the left arm, around the middle of the triceps with the bit shown above facing backwards. If you can’t picture that, I’m sure you can Google an image up.
.What is it/How Does it Work?
The GWF is actually one of several different recent devices the purports to measure caloric expenditure. While things like heart rate monitors have claimed to this for a while based on heart rate, the GWF type devices got a bit further including 5 different sensors which measure acceleration, temperature, steps, galvanic skin response and heat flux. It plugs all of those into an algorithm and calculates how many calories you’re burning on a minute to minute basis. Some of that algorithm is based on your height, weight, age, gender, etc. that you plug into the system after you sign up.
The device is then plugged into a computer and the data uploaded to a piece of software that interprets it and shows your caloric expenditure over the course of hours or days or whatever. I’d note that there is also an additional watch that can be purchased that will show you a more or less real-time (it’s actually averaging every 6 minutes) measure of caloric expenditure. This can be useful if you’re tracking workouts to a ‘Burn XXX total calories’ goal. But for measuring daily expenditure, you’ll generally use the online tracking software (which also stores previous days which can be nice).
From a technical standpoint, the GWF uses a standard USB cable and charges off of the computer itself (I think this was one big difference than the Bodybugg which used AA Batteries). It lets you know what the battery status is and holds a charge pretty well. If you get in the habit of hooking it up while you’re in the shower, it will stay charged for quite some time.
I’d mention that the device is pretty sturdy and you can sleep with it. One of it’s more interesting features, which I’ll mention below is that it gives you an estimate of sleep efficiency, effectively the percentage of time that you’re actually asleep while you’re laying down. I have no clue how it does this but it seems to be accurate (e.g. it’ll catch if you wake up and roll around or get up to pee or whatever); I honestly suspect a pact with Satan is somehow involved.
The online software is actually fairly good, even if their server seems to have issues with access more often than it should. It will access the armband via a standard USB port and give you a lot of different data including caloric expenditure, sleep efficiency and others. It also has some basic calculators for things like energy expenditure for different activities (e.g. enter that you ran 60 minutes at 6.5 mph and it will spit out calories. You can also get weekly average reports and such.
One thing I want to mention that the GWF does NOT do but some people think it does. On the site, they mention that they will let you track caloric intake. And you can but you do it manually, by entering food records. The device in no way actually measures what you ate in a day. And while a new device worn on the arm claims to do just that, apparently it’s only accurate to plus or minus 500 calories per day which is useless as hell. But the GWF does not measure caloric intake, you can enter your food online manually and that’s it.
I would mention that their interface only works with selected Browsers and this can get irritating; the last time I looked for example, Safari 4 was not supported and neither was the higher build of Firefox for Mac. When I updated my browser I lost the ability to access the online software.
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Is It Accurate?
A limited amount of validation data has been done on the GWF but has found that it is at least reasonably accurate. Certainly nothing is 100% and the GWF isn’t either. It seems to mis-estimate certain situations more than others but, overall, seems about 90% consistent or so with other, more accurate measurements. Which is pretty good for the most part.
Speaking empirically, I’d note that I’ve played with the GWF in myself and one of my trainees and compared the values it spits out to other measures. For example there are standard calculations for resting energy expenditure based on body surface area, the GWF hits them pretty much exactly.
I’ve also compared it to things like a heart rate monitor measurement of exercise energy expenditure, as well as the number that the machines spit out themselves. The numbers are never exactly the same but they are always within shooting distance of one another. Certainly the difference is never massive (and since these are all estimations, this is no surprise).
Since I’ve mentioned my Powermeter bike on the site before, you may be wondering if I’ve compared GWF values to the kilojoule numbers the bike produces. And the answer is no. One place where the GWF completely craps out is in estimating cycling energy expenditure. Since one of it’s major determinants is the accelerometer, and that only works if the left arm is moving, the GWF does a horrible job with things like cycling (their site even acknowledges this). I’ve seen it suggested to wear it on the calf while cycling but never tested this out to see if it gave better numbers.
I’d note in that respect that it is possible, in activities where the left arm is being moved vigorously for the GWF to produce absolutely insanely high caloric expenditure values. Just impossible values. I’ll let the more dirty-minded readers do with that statement what they will. Moving on.
I’d note that the daily caloric expenditures that the GWF spits out come awfully close to some of the standard estimations that I’ve thrown out on the site. Which actually raises the question of what the GWF does that the method described in How to Estimate Mainteanance Calories – Q&A doesn’t do for free. Which is a good question.
I’d also note, and this based purely on forum feedback, that the GWF seems to just be horrible at putting out good values for a small percentage of people. I’m not sure why this is the case but a generality that seems to be showing up is that folks with thyroid issues don’t get a good measurement off the GWF, it seems to overestimate.
I’d note that this conclusion is being based on people looking at weight changes relative to what the GWF is saying their expenditure is and what the ysay their caloric intake is. This introduces a number of possible problems (not the least of which being thyroid mediated water retention that masks fat loss or problems with actual caloric expenditure).
But for the most part, I’ve found that the GWF not only correlates well with both standard equations and other measurements of energy expenditure, it can pick up changes in activity very reliably. Get up and walk around for a few minutes, and the GWF will pick it up; go watch a movie and you’ll get a value that is not dissimilar from sleeping for the entire time. It’s not perfect but it’s damn good.
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Why Should You Care?
Even with standard estimate equations like the ones I constantly talk about on the site, there can still be some real questions about total daily energy expenditure. If nothing else, the GWF at least takes a decent stab at actually measuring it. For people with either very high or very low activity (or simply activity that changes a lot on a day-to-day basis), having an actual number to put with that activity can be helpful.
So, in terms of who the GWF can be good for, one of those is the typical dieting obsessive compulsive. For those people who just have to have a better value than what estimate equations provide, the GWF is worth considering.
As well, for people who have varying activity levels, whether in terms of work or exercise training, the GWF can help to get values on the different workouts. Days off or very easy days may end up having very different energy expenditures than heavy training days. Athletes or dieters trying to really match intake to output can get data on those different days to better set their nutrition.
The GWF can also have a couple of other less obvious uses. One of them is this: many people find themselves subconsciously trying to move more when they start using the GWF. The graphs are kind of exciting and people start moving more to watch the numbers go up (one trainee who used it had a goal of hitting a 4000 cal expenditure day for example). It’s like when you make people start writing down their food and they start eating less spontaneously. Something about knowing that the device is measuring energy expenditure makes people want to move more.
In that vein, one of the more intriguing things that the GWF shows is how much small bits of activity throughout the day really add up. That is, the difference between someone who literally sits for 8 hours per day and one who gets up even a few times during the hour to move around can add up to a fair few hundred calories. Over the course of a week or a month or a year this makes a massive contribution to energy output.
Related to that, many people are actually quite disappointed to learn that activities of daily movement often burn far more calories than formal exercise. One trainee was distraught when she found that 3 hours of yardwork burned TONS more calories than 3 hours in the weight room.
A final effect (more than a use) of the GWF is that it’s done a good job of getting people who ‘swear they only burn 1200 calories a day and have to starve to maintain weight’ to realize that their daily energy expenditure is actually much higher than that. Many people on forums have found that they can raise calories a lot higher than they had been eating without weight or fat gain. Basically, it ends the “Slow metabolic rate/low energy expenditure” claim because it gives objective data on what’s really going on. Of course, people determined to believe that they are special will just ignore the data.
But in terms of actually getting a good estimate on what different days of the week or different activities burn on a day to day basis or what have you, the GWF is a step above using an estimation equation or trusting the caloric expenditure reading on the treadmill.
I should mention sleep efficiency. As I discussed in Obesity and Inactivity: The Relevance of Reconsidering the Notion of Sedentariness sleep deficiency is not only fairly widespread in modern life but a real problem in terms of health and propensity to weight gain. One thing the GWF does is give a measure of sleep efficiency, a simple percentage indicating how much of the time laying down was spent sleeping.
This gives users the ability to track how lifestyle changes (e.g. sleep hygeine, sleep supplements) are impacting their sleep so they can try to raise the total amount of sleep they are getting. You can test different dinner meals or when you train or whatever and see what gets you higher efficiency numbers (my limited googling suggests that 85%+ is a good value, nobody gets 100%). For people with sleep issues, the GWF might be useful just for that.
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What’s the Catch?
So the above section is sort of the pros of the GWF. Let’s you get a more accurate picture of what you’re doing on a day to day or workout to workout basis, etc. What are the cons?
The first of course is price. The unit is not cheap (it’s not absurdly expensive), Amazon currently lists it at $179.00. However, for reasons I’ll come to, you can usually pick up one on Ebay. Unfortunately, that’s not the only cost involved. To get the data off the thing you have to have a monthly account with Bodymedia to access the data. And no you can’t use the watch to get around this, it will eventually fill up and you can only clear it out by accessing the website.
Admittedly the website isn’t expensive, like $12.95 per month or something (I can’t actually find the value on their site at the moment). I’d note, and they go out of their way to avoid admitting this is the case, but you can transfer accounts. So if you chose to buy a unit off of Ebay you can take over their account and change the user data and it will work just fine.
Also, the GWF can’t be purchased outside of the United States; I have no idea why but anybody who isn’t in the US will have to have a friend buy it and ship it over.
And that brings me to possibly the biggest issue with the GWF. For most people, day to day and week to week activity doesn’t change massively. You probably work Monday through Friday, weekends off, train certain days and you’re training is unlikely to change massively over time (this may be different for athletes whose training changes a lot during the year).
What this means is that after you’ve gathered data with the GWF for maybe 2 weeks, it becomes fairly useless. Unless you’re in that situation where your activity is highly variable, you’ll have every thing you need from the device after that short time span. And that’s a fairly large investment for 2 weeks of use.
There are options around that. One is to buy one used off of Ebay. And then sell it again when you’re done with it. As I mentioned, you can change the user data and transfer accounts even if GWF says you can’t. Another option is to get together with a few like-minded fitness obsessives and buy it in a group. Split across 4-6 people, it’s fairly cheap and you can just rotate it through every 2 weeks as people use it and get the data that they need.
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Summing Up
So the GWF, is it worth getting? Overall I say yes. It’s one of the more accurate devices and for people trying to optimize their overall nutrition and body recomposition can provide some rather invaluable data on what’s actually going on. The problem being that, once you have those 2 weeks of data, it’s fairly useless. You can keep using it, and if your training changes or increases drastically, it may have use beyond that. It’s not super-cheap and the monthly fee to use the website is annoying but that can be gotten around with creative sharing or Ebaying.
My Books
Related Articles
- Lean Mass or Total Weight to Set Calorie Levels – Q&A
- A 45-Minute Vigorous Exercise Bout Increases Metabolic Rate for 14 Hours – Research Review
- Dissecting the Energy Needs of the Body – Research Review
- Obesity and Physical Inactivity: The Relevance of Reconsidering the Notion of Sedentariness
- Normal Weight Men and Women Overestimate Energy Expenditure – Research Review
I would add a word of caution. For those with a perfectionist tendencies or those who are wayyy to focused on the daily in and out, this gadget can be a bad (psychologically), for me, it brought on ED behaviours and overexercise. So…caveat emptor
I have been debating getting one of these devices. Leigh Peele did a great review of them and seems to use them a lot with clients and said they are at least 15% inaccurate and she thinks in some cases more with endurance training. You are saying 90% so what do you think?
Here is the article link.
http://www.leighpeele.com/gowear-fit-and-bodybugg-a-comparison
Lyle,
Would a left-handed tennis player be likely to get screwy measurements during that activity given your comment about wearing it on the left arm?
I’m not looking into getting this device, just was curious since I am right-handed when I play tennis, but my wife is a lefty.
Lyle,
I have been hesitant to try this product out as I feel I have a fairly good gauge of my caloric burn on a fairly regular basis, but your article has revived my interest in the product again. That being said, I usually get the majority of my cardio (anywhere from 30 minutes to 2 hours a day, depending on the conditions/other things taking place in life) from cycling. If I wanted to get a more accurate picture using this device, would I take it off during the period of cycling and just use my normal estimates for the cycling, or should I keep it on/will this have any negative impact on the devices overall daily reading of my caloric expenditure?
Thanks,
Joe
Wearing one of these for a while was big factor in my decision to set up a treadmill-desk at work. I had not realised how absurdly low my calorie burn was during the day while seated. You can’t really make up for it with just an hour of exercise most days.
Lyle,
Would that thingy show increases in metabolic rate while on various thermogenics (EC, Clen, DNP)?
Lyle, did the difference in software make one a better option over the other?
Uagmata: I do not disagree with this at all. But OCD types are going to be OCD and at least this will let them get good data.
Jackson: The studies reported 90% I believe. I’d be curious how she came up with 15% inaccurate. Because without a perfect method of measuring true energy expenditure (and the only thing close is doubly labelled water), she’d be pulling that number out of thin air. I’ve seen people report that the numbers were accurate to about the gram, and, as noted , tine article, some who feels that it over-estimates.
Mike: That’s a good question. For whatever reason, the device is meant to be worn on the left arm. It might very well give overestimates for a left-handed tennis player.
Joe: Since I had the powermeter bike, I just took the thing off when I rode the bike and used the bike’s value. One thing I forgot to note in the article is that the software will let you enter what you did for times when the Bugg was ‘off-body’. And that means that you could put in the cycling workout (it has a rudimentary calculator) that way to get a daily total.
Lyn: Exactly. that was my point about little bits of activity during the day adding up WAY more than an hour of training. Basically, moving around a little for 8 hours a day burns far more than sitting on your butt 8 hours a day and doing cardio in the gym for one.
Anon: We only tested it with EC and saw no difference. But I suspect this has to do with the fact that EC has, at best, a small effect (perhaps 5% over several hours). that wouldn’t show up on a minute to minute basis.
William: I never actually worked with the original software so I can’t comment.
@ Lyle:
True. That data was a mixed blessing for me. In a weird way, it kind of ‘cures’ some OCD tendencies to see that you can in fact choose to take a long walk instead of lifting weights on occasions where you feel physically unable to do so (injury etc)…and end up at your planned deficit. Now only if it came with the function of zapping you when you go too far and double your deficit through OCD…
@ mike
I recall being asked whether I was left/right handed when setting up the device… so perhaps it works for lefties. I would say call and ask them, but the customer service is horrendous
@ Anon
If I recall correctly, some folk on fitness forums reported a jump in expenditure when using DNP…purely anecdotal evidence so take it at face value
@Lyle
The number was not pulled out of thin air. It was stated as an estimated and as an educated estimate at that. If you remember, I have done plenty of testing with Go WearFits and Bodybuggs. The numbers seem to skew extremely with those involved in marathon/triathlon training and those with eating disorders/thyroid conditions. People with readings up to 5000 calories a day, but with no signficant change in weight loss even with a calculated and measured deficit. This doesn’t mean they are void of energy laws, but it does mean the device is overestimating expedture. There is only so much water cloaking that can happen over a span of time before you say a device is off in its reading.
When you add in the various abnormalities with cycle movements, motorcyle riding and various other small things like that, it adds more to discredit.
Also looking at this study…
Clin Nutr. 2008 Apr;27(2):307-10. Epub 2008 Feb 13. Links
Poor agreement between a portable armband and indirect calorimetry in the assessment of resting energy expenditure.Bertoli S, Posata A, Battezzati A, Spadafranca A, Testolin G, Bedogni G.
International Center for the Assessment of Nutritional Status, University of Milano, Milano, Italy. simona.bertoli@unimi.it
BACKGROUND & AIMS: To evaluate the agreement between resting energy expenditure (REE) estimated by a portable armband and measured by indirect calorimetry. METHODS: One-hundred and twenty-seven women and 42 men with a mean (SD) age of 44 (12) years and a body mass index of 30.2 (5.4) kg/m(2) were studied. REE was estimated using the Sense Wear Pro 2 Armband (SWA), measured using the Sensor Medics 29 metabolic cart (V(max)), and estimated using Schofield’s equation. The limits of agreement (LOA) and the concordance correlation coefficient (CCC) were used to evaluate the interchangeability of the methods. RESULTS: The LOA between REE(SWA) and REE(Vmax) were wide in both women (-269 to 378 kcal/day) and men (-330 to 545 kcal/day) and CCC was low (0.579 in females and 0.583 in males, p<0.0001 for both). REE(Schofield) agreed with REE(Vmax) to a similar degree (CCC=0.563 in females and 0.500 in males, p<0.0001 for both). CONCLUSIONS: SWA and indirect calorimetry are not interchangeable methods for the assessment of REE in normal-weight and obese subjects.
It adds another log to the fire.
Not to mention tests I did comparing it to Bodygem.
All that combined left for various percentages of assumed off readings ranging from as high as 26% mixed with tracked weight, food intake, activity, etc. Did I say it was an exact number? No. I stated, exactly – "In my personal opinion only, I would allow for at least a 15% error in reading. I would use them only for alertness to your actual movement in life, to understand that caloric burn is not static, and as a gauge of where to start from to reach your current body goal."
I would read the entire article as it was linked. I think you will find other than a few remarks we agree on the subject.
I love my gowearfit mostly because it gives me some extra incentive to move more. It also really taught me that long hikes/cleaning the house/sports are far far better at burning calories than anything you can do in a gym. I train with decent intensity for about 1.5 hours but when I take a long hike on the weekend that seems leisurly to me, my calories burned numbers are much higher for the hike day. This device really shed a light on the whole NEPA/ NEAT theories for me. Also its a big kick in the pants when your calories are really low after you sat around all day, its highly motivational for me. I wonder about its accuracy sometimes, especially with regards to driving, but Id recomend this to anyone trying to lose weight, mostly as a motivational tool.
Without this tool, I would have still be caught in the old skool way of thinking that exercising hard was the way to go to burn calories.
After which I realize that, if i could do it easily and enjoy myself that I could enjoy dieting without killing myself.
It has changed my perspective indefinitely on how I address weight loss issues.
Some of the validation work on the Gowearfit indicates that it had an error rate of +/-300 kcal/d in about 80% of people. So essentially it’s pretty good in 4 out of every 5 people. That’s quite a bit better than all the other methods used to try to estimate total daily energy expenditure.
However, the research also did show that it tends to underpredict energy expenditure for people at the very low end of the spectrum, and tends to overpredict energy expenditure for people at the very high end of the spectrum, which would be in agreement with Leigh’s observations.
I know, for me personally, it was pretty much right on. It would get my total daily energy expenditure at around 3200 kcal/d, which is right around the amount I need to eat to maintain my weight.
Probably a nice device, but why not juste listen to your body? It dosen’t take much time to learn how many calories you are using, count your calories for a couple of weeks and you are done.
Fredrik: Because calories in are not calories out. how much your’e eating tells you nothing about how much you’re burning and if you could just ‘listen to your body’ nobody would be fat.
I’m definitely one of the endurance types for whom there’s a big discrepancy. Yet I plugged away with the thing for a whole year. I’m ready to sell it, by this point.
I know and have seen that NEAT nearly rules all. I now know that sitting at my desk burns shit for calories (50/hour!!!!). Oh, and the GWF is pretty useless in hot yoga. Swimming, too, of course. So its not just cyclists with the short end of that stick.
Because I am well-trained, endurance does not burn nearly as much as it “should” even for my size. The GWF picks up on that to a small degree – for example it said that I burned just over 2000kcal in a marathon, so that’s less than 70kcal/mile, and of course I was not schlepping along.
With an average deficit of 500+ for a year, I should be about 70lbs by now, so there’s something off.
Am I a thryroid “case”? How would I know? If you have a little guidance I’d love to hear it. I also have a year’s worth of data if you’d like to have at it or just use it for analysis. That includes INTAKE, as well, measured pretty damn accurately (gram scale, etc).
OH….. on the left/right arm thing – I’ve switched it back and forth. When I do, I just change the “handedness” setting to theoretically negate the effects of the move. Other wise you get a crazy dent in your arm without one in the other arm. At least now I have equal dents.
I just started wearing my GWF again. I hadn’t worn it in about a month (wasted this month’s subscription cost). The device is cool and motivated me to constantly check how many calories I burned, steps taken, etc. however, the bad thing about it is that I must have some sort of skin allergy to the strap and the metal that is on the back of the GWF that touches my skin. I have broken out in a rash and have scars from where the bumps were (they resembled pimples). I can’t even wear it on my left arm anymore as that side itches really bad when I wear the device. I now have to wear it on my right arm.
If I had to do it over again, I’d probably have bought a better pedometer and heart rate monitor. The GWF doesn’t have a heart rate monitor, but it does monitor my sleep, however, what it does measure for sleep isn’t all that accurate. For example, I’ve kept the GWF in my gym bag for the last 3 weeks and when I checked it for the first time this morning, I noticed that on one day last week (I wasn’t wearing it, it was in the gym bag) the GWF registered that I got 11 hours of sleep. I’m not even sure how the device turned on as I thought the metal tabs on the bottom must touch skin (I guess I’m wrong).
@MissTenacity:
According to James’ post above, it could be off by as much as +/-300 cals a day. Or if you read Leigh’s post, ~15% inaccurate. If you’re only using a 500 calorie/day deficit, that inaccuracy could all but wipe out your fat loss.
To find out if you’re a thyroid case, just go see your doctor. It’s a simple blood test. In fact, you might be able to order a home test online.
Since you’re quite experienced at tracking your food, the really simple answer is to just drop your calories until the fat loss you want happens.
I bought my GWF and started using it on August 4th, I was shocked at the readings after the first day. I run an in-home daycare and thought for sure that I was burning way more calories than I actually was. Now that I have my GWF I can keep track of my intake and expenditure and it has helped me out a bunch. I have lost a total of 13 pounds since I started, could I have done this with out it? Maybe, maybe not I have tried before and was never this successful. I am so glad that I decided to buy one.
First, this is an excellent review – probably the best I have come by thus far.
I am curious if you know of another, similar system that can track skin, heart, and steps but doesn’t require me to have a monthly subscription?
I’m not aware of anything although I wouldn’t be surprised if someone develops some sort of open source software to let the data on the bugg be taken off without the paid description. At the end of the day, unfortunately, there’s more money to be made in a subscription services than not. I’d remind you that, in all honesty, once you’ve used the Bugg for a few weeks you have about all the data you need. The membership is easy to cancel or you can sell the Bugg to someone else and let them pay for it.
hi, currently there are 2 programs (AFAIK) to extract data from a bodybugg without using their paid subscription, one is a dirty-hack coded in python (bodybugglinux.blogspot.com) and the other one is a more polished java coded program (look for a group in facebook called “FreeBugg and other Bodybugg hacks”)
regards!
One of the interesting things with this gadget is to see how resting metabolic rate is changing in response to daily activity and food intake. By measuring the interval midnight to 6 am for instance and multiplying by 4 one can get to an estimate of resting metabolic rate. It is interesting to see the response to workout intensity and other key parameters. I have found the caloric measurements to be way off ! on eliliptic trainer compared to the heart rate monitor, which is logical as the arms is not moving as much…
I found this thing to be of limited usefulness…I like the food intake registration part, it makes you really focused on the calory counting… which is good.. the challenge remains the non at home eating though.
Lyle, I am curious as to what diseases of the thyroid you are talking about when you mention variables that can skew the reading from the Bodybugg. Specifically, if someone has hypothyroidism, but levels are WNL due to replacement, are you still getting reports of off readings?