Skulpt Chisel Review: Fat Measurement Made Easy

The Skulpt Chisel is Skulpt's second generation body fat measurement device.  It's faster and it's cheaper, but is it better at measuring body fat and muscle quality?  Here's my review after using it for a few months.

I obtained Skulpt's first body fat measurement device, the AIM, about a year ago and really appreciated its combination of technology and user-friendliness.  While I enjoyed using it, it still had a few drawbacks - one of which ended up forcing me to stop using it - the battery life got shorter and shorter over time.  So when I heard about the Chisel, I was hopeful that Skulpt was able to overcome this and a few other drawbacks to the original device.  See my full review of the Skulpt AIM here.  For this post, I'll borrow some of the background information on the device and its technology from my previous review, then will discuss  the  specifics of the Chisel.

What is the Skulpt Chisel?
It’s a small (think of iPhone-sized) handheld electronic device for spot-measuring body fat percentage and muscle quality (MQ).  It does this by sending electrical currents through your skin and underlying fat layers.  Now you’re thinking – “body fat percentage I understand, but what the heck is muscle quality?”  According to the company, “it means the force a muscle produces relative to its size. For example, if you had two muscles that were exactly the same size, the one that produced the greater force would have the higher MQ.  The Chisel measures the composition and structure of the muscle over a specific region. Since those two things affect how strong the muscle is, we can give you your MQ without having to do a strength measurement or taking out a tape measure!”

Why knowing your body fat percentage is important
Throughout my weight loss process I worked with a personal trainer who took several measurements on a regular basis – my weight, body circumferences, and my body fat percentage.  Having that body fat percentage measurement was really helpful during the process because some weeks I lost less weight than others.  By knowing my body fat percentage, we were able to determine if I was gaining muscle or losing fat.  My trainer had access to a fancy Bio Impedance Analysis (BIA) machine (manufactured by InBody) that was pretty accurate, but once I reached my goal weight I stopped going to the trainer and I was on my own.  
​
I still continue to weigh myself, take body measurements and body fat percentage to gauge my progress towards my current fitness goals.  I have a scale and a tape measure, but body fat measurement is more problematic at home.  I’ve been using fat calipers for a long time, which can give a good rough estimate of body fat percentage.  But when I heard of the Skulpt device, I had visions of having something similar to the InBody machine that I could actually afford.  It currently retails for about $100.  Not cheap, but somewhat affordable for a fitness enthusiast.

How do you use it?
I have been using the Chisel now for a few  months and I can say that I’m really enjoying it.  

It works in conjunction with your smart phone.  You control the device by connection it with your phone through a Bluetooth connection, and the phone also displays your results.  You can measure any single muscle, do a "quick test" (the right bicep, the right tricep, the right abs, and the right quads), or do a complete body test of 24 muscles on both sides of your body. 

To take a fat percentage and muscle quality measurement, you have to first moisten the metallic sensors on the back of the device, then you hold the device over the body part you want to measure.  They include a small spray bottle for moistening.  If you're doing a full body scan, it helps to wear minimal clothing and prepare to get a little wet.  The phone app shows you where to position it for each muscle.  Since the device is sensitive and readings can vary just by moving it a little, you end up moving it around a bit until you find the best reading.  The values are displayed on your phone, and when you hold it still for a few seconds the reading is made.  Then on to the next muscle to measure.  Once you get the hang of it, I would say it takes about a minute to do a quick body fat percentage reading, or about 5 minutes to do a complete one.

The app
The app is available for both iPhone and Android smart phones.  You must have one of those types of phones to use the Chisel.  As you can see below, the interface is pretty simple.  At the top, you'll see there are two modes - "Muscle Quality" and "Body Fat".  By tapping either one, you display that mode.  At the bottom of the screen, by tapping either arrow you can show the muscle groups for the opposite side of the body.

You can take body fat measurements in three different ways.  First, you can hit "Quick Scan" to do an overall body fat measurement based on the right bicep, the right tricep, the right abs, and the right quads.  It should be noted that this is the ONLY way to get a general body fat measurement.  Intuitively you'd think that by doing a full body scan of all 24 muscle groups that you would get a more accurate body fat percentage, but it ignores that additional information and will always use the quick scan muscle groups to give your overall body fat percentage.  

By tapping on any body part, it takes you to a sub-screen where you can see your current and historical readings for that part.  You can also take a spot measurement of just that part.  The historical readings are one of the things I like most about the Skulpt.  Because even if the readings were a little off, it's by far more interesting to see the trend over time. You can more easily assess whether you're headed in the right direction or need to make a course change.  You also get a spot assessment of whether the body fat percentage for the muscle group (Needs Work, Fair, Good, Fit or Athletic).  

The same holds true for the overall body fat percentage, it gives you a graph of historical readings.

Using the information
​I have to admit I was a bit saddened by this at first, because as you can see from my own readings, If I were to average all the different body fat percentages it would be somewhere in the 16% range instead of the 18% it reports.  Even the quick scan isn't an average, it is heavily weighted towards the abs percentage, which happens to be the worst reading for most men.  But if you look into the science of body fat measurement, there is research that shows that a fairly accurate overall measurement can be based on just a few readings.  I would hope at some point the full power of the technology could be leveraged to better use ALL of the data it collects to give a more accurate reading.

So if you only need to measure four specific muscles to get your total body fat percentage, why have the ability to measure 24 muscles?  The concept is that if you want to look at the percentage of fat for a specific muscle, you can do it.  So if for example I measure a muscle and it says "Fair" in terms of body fat percentage, my inclination would be to exercise that muscle to spot-reduce it.  That would be the wrong approach. Anyone who knows about body composition and fat distribution knows that you can't spot-reduce fat.  If that were possible, I would do hundreds of crunches and all of a sudden the layer of fat over my abs would disappear.  No such luck.  So what is the information good for?  Well, to me it seems like it's useful to know how your fat is distributed.  For example, looking at my full body results at once I could see areas where I was lean and areas where I was not as lean.  Through exercise, eating well and taking regular measurements with the Chisel, you can tell if your regimen is giving the results you desire.  Theoretically you'll see those areas with a higher fat percentage go down over time. 

Another thing to beware of is thinking that there is a single good value for body fat percentage for every muscle.  Yes, your overall goal might be something like 10% body fat, but that doesn't mean every muscle should be at 10%.  Some will naturally be higher and some lower.  So the people at Skulpt give you feedback specific to the muscle group, which is a nice concept unique to their device.

What to do with muscle quality
The concept of "muscle quality" is a new one for most people.  Along with fat percentages, the Chisel gives a number for the muscle quality for each muscle measured.  The higher the number the better, the range going up to 100.  There is also a similar rating to the body fat if you tap on a muscle (Needs Work, Fair, Good, Fit and Athletic) along with the historical readings and graph.

As I said, you can't spot-reduce fat, but you can spot-increase muscle quality.  I found that in general if the Chisel was telling me that some muscles were lower in quality, if I focused on them for a couple of weeks I could bring the numbers up.  Having said that, I don't think I would necessarily focus on this information to plan my workouts.  I think a good, solid, balanced resistance training program where you exercise all major muscle groups will give you results.  But the AIM's feedback could be used to determine if an area is being neglected.  I would never alter my routine based on a single set of measurements, however.  I would record and monitor the readings over several weeks and then determine if I needed to change anything to address areas of neglect.

Counseling and advice
A new feature of the app is called "Analysis".  It's like a personalized message center that gives you advice based on your goals and physiology.  I received about three messages after installing the new app, but it hasn't updated since. So I would put this one more under a work in progress since it would be nice to get a stream of ongoing advice.  The information I did receive basically said that if I want to get lean (my current goal), I should target a specific caloric and macro intake that it recommended.  It would be great if Skulpt could leverage the specific information the Chisel collects to help you understand it better.

Technology and accuracy
This section borrows heavily from the Skulpt web site - for more information on the technical details, go there.

Dr. Seward Rutkove, Skulpt co-founder, is a neurologist at Harvard Medical School. As a physician and researcher, he was frustrated that there were no good ways to measure muscle health. He embarked on a mission to find or develop a better way to measure muscles 13 years ago. In collaboration with physicists at Northeastern University and engineers at MIT, he developed and tested the earliest prototypes that measured Electrical Impedance Myography (EIM).

The Chisel is classified as an EIM device.  It measures electrical current flow in different directions and it can measure the flow at different depths (the further apart the electrodes, the deeper the electrical current will penetrate).   By combining these multiple electrode configurations with multi-frequency electrical measurements, and by using a variety of algorithms, the Skulpt Chisel can separate out the condition of the muscle from the amount of fat in a region in just a matter of seconds.  

How does this compare to something like the electronic weight scales that also measure fat percentage?  That technology is called Bioimpedance Analysis (BIA).  This technology is much less accurate, since the current can follow the path of least resistance through the body.  Since the current is flowing from foot to foot, or between hands and feet, it goes through other tissue that has no bearing on body composition (muscle or fat), which skews the results.  The EIM approach is better because it is over a smaller area with an optimized sensor and current configuration.  

Skulpt claims that even EIM is subject to some inaccuracy due to changes in skin condition, temperature, and subcutaneous blood.  But those are much smaller than the inaccuracies inherent in the BIA approach.  I have a fat-measuring scale and it is at least 7-8% off of what the Chisel and calipers are telling me.  

I don't really have access to good high-end body fat measurement devices to really gauge the accuracy of the Chisel.  I do continue to use calipers to measure my body fat, and the Chisel tracks about 2-3% higher than a 3-site skinfold calculation.  Using the older Skulpt device, the AIM, I found that it tracked more closely with the calipers. The difference wasn't in the device, however.  With the release of their newer app they re-did their calculation algorithms and it resulted (for me) in a higher body fat percentage.  I had to think about that a bit.  My actual body fat percentage didn't go up.  It was at that point I realized that for almost any measurement device you need to look more at the trends over time and not as much at the specific values.  Then you can tell if you're headed in the right direction for your fitness goals.  

Who it's for
​At a current price of around $99, the device is becoming more affordable for a fitness enthusiast, but probably not for average people.  I would say that the people who can benefit the most from this device and technology are those who have definite fitness goals and are putting together training plans to accomplish them.  My experience is that it is better than using calipers, and gives more information to work with.  And compared to other higher-end measurement devices, it is much more affordable.

The Skulpt company is serious about marketing, selling and supporting this device.  If you Google reviews and discussions around the Chisel you'll find pros and cons.  My experience has definitely been a good one and I'm glad to have this great device in my collection of tools I use to measure and improve my fitness. 

Comparison to AIM
I had the first Skulpt device, the AIM, so here are a few of my impressions on how they compare.    The battery life on the Chisel is much, much better than the AIM.  I had to eventually stop using the AIM because it wouldn't hold enough charge to get through a full body measurement, whereas the Chisel I can charge and use for a few full measurements.  While the readout on the AIM was cool (you could basically use it with or without your phone), I found the menus and navigation cumbersome.  Eliminating the display and requiring a phone was a good step, since the phone has a richer app environment.  The app itself has also improved quite a bit - it's simpler, easier to use and the results are easier to understand.  I'm guessing that the AIM benefited from the app improvements as well.  And the price went from $150-$200 for the AIM down to $99 for the Chisel.  All in all, if you have the AIM you should still get the Chisel, it is a huge improvement.

Rating

Pros

• Based on new, research-driven technology
• Easy to use app
• Tracks measurements over time
• Great support, constant updates
• Accurate body fat measurement
• New concept of muscle quality

Cons

• Analysis feature of app could use more work
• On the expensive side for an average person
• Overall body fat measurement is only based on four muscle groups, rather than all of the data available, and seems to be largely skewed by the abs reading

I highly recommend the Skulpt Chisel - it's truly a revolutionary tool that turns body fat measurement from a difficult task to an easy one.  If you have any questions, write in the comments below or use my contact page and I'll answer them.