I Got Dunked! My First Hydrostatic Body Fat Test
Yesterday I got my first hydrostatic body fat test. Since my Whole30 ended I’ve been anxious to know what my body fat percentage is and I’ve been wanting to get an accurate body fat test. Every time I’ve been measured on my doctor’s body fat test scale, I’ve been very disappointed with the results. How could I lose nearly 20 pounds to date and yet my body fat has only dropped from 33% to 30%? It didn’t make sense to me. My doctor uses a body fat scaled called Tanita Body Composition Analyzer. You step on the big metal scale and it calculates your weight and body fat. On the day I went in to get my bloodwork checked after whole30, I was at 29.9%! I didn’t understand how all the inches I’ve lost since April (including 2 pant sizes) and perfect eating for 30 days couldn’t even get me to a healthy body fat ratio. It was discouraging to think I was eating so perfect yet still considered borderline unhealthy as far as body fat was concerned. I needed to better understand what was going on with me. Frankly, I was worried.
The more people I talked to, the more I learned that the method I was using to test myself was inaccurate. I told my coworkers about my body fat level being at 29.9% and they said there is no way. They even took my measurements (they are clothing designers) and used the Navy Body Fat calculator to show me what my body fat was. According to my measurements, the Navy test said I was at 24%. While that was flattering, I didn’t know what to believe anymore.
I’m a big fan of research and the more I researched the more I learned about hydrostatic weighing and hydrostatic body fat testing. It is considered the gold standard of body fat testing and the most accurate body fat test. They basically place you in a “dunk tank” underwater for 5 Seconds and measure your body fat. And because you’re submerged in water it doesn’t mix up water weigh for fat like a lot of other body fat tests do. Awesome.
I went online to bodyfattest.com which is a mobile hydrostatic body fat test. They pull right up to a location and measure your fat. Sweet. I saw they were going to be at a gym called Crossfit Intrepid in El Segundo this week. I made an appointment and went. When I got there I went into the changing room and hanged into my bikini and got weighed. I was surprised my weight was at 140 pounds because lately I’ve been around 138 in the middle of the day. But I did drink a lot of water that morning so it could have been water weight. And honestly, I didn’t even care if my weight was higher as long as my body fat was down. Then he took my height. Then I got in a bathtub like contraption and sat with my legs out in front of me and put a weight belt over my knees. Then it was time to get dunked!
For the dunking part I had to plug my nose, lean back, and completely submerge myself in water while blowing all the air out of my body until I had nothing left. Then the guy would tap the tank and I would know to come up. I had to do it enough times until he got two consistent readings. I ended up doing it three times. It was a little weird blowing out all my air like that but I did what I had to do.
After that I got dressed and they shared my results with me. The hydrostatic body fat test showed that I am at 23.5% body fat…23.5%! This is a difference of almost 7% from what my doctor had me at! That was such exciting and relieving news to me. I almost wanted to cry tears of happiness! I told the tester that my doctors scale had me at 29.9% and he said there’s no way. Last week my trainer at the gym and all my coworkers told me there’s no way I’m 29%. I thought they were just being nice, and maybe for some reason I just have a hard time losing fat. I am SO happy to learn my hard work IS paying off and this is not the case. Music to my ears! Here are my ratios by the numbers:
Body Fat: 32.85 lbs, 23.5%
Lean Body Mass: 107.35, 76.55%
I asked the guy Brian who did my body fat test a lot of questions. I told him about my doctor’s body fat test and where I was at and he said he had me in a very different place. My doctor had me aiming to be between 24-26% body fat and right now I’m even below that. WOW! I am just so thrilled beyond words. My whole life I’ve struggled with high body fat levels and now I’m finally reaping the benefits of my hard work. I’m just so happy. I just can’t believe it. Never in my life have my body fat levels been considered “good.” This is just the best news ever. Now I’m very anxious to get my blood work results back from my doctor and see how my cholesterol is doing. I will continue to keep you all posted on my progress!
So what’s next? Well, I am going to continue to stay on the clean eating path and participate in the Whole Life Challenge for the next 7 weeks. From there I am going to work on toning up and getting strong. I am okay with gaining weight if it means I will become leaner but right now I’m just going to soak in and enjoy the progress I’ve made to date. Onward!
What about you? Have you ever had a hydrostatic body fat test? How do you measure body fat? What do you think is the most accurate? Post in the comments and let me know!
Wow! Great work!!!
The first thing I thought as I was reading your blog post was that there’s absolutely NO WAY you ever had a body fat percentage of 30-33%. Dude needs to swap out his body fat technology! Congrats on your results Lindsay.
I’ve never done a dunk test, but I do use a an Eat Smart body fat scale, and I tend to think its pretty accurate. It has me hovering between 23-24%, which seems about right. The thing I like about this scale is it also measure Body Muscle percentage and Water/Hydration percentages.
This is the scale I use:
http://www.amazon.com/EatSmart-Precision-Capacity-Recognition-Technology/dp/B004L6NTHU/ref=sr_1_1?s=hpc&ie=UTF8&qid=1361900382&sr=1-1&keywords=eat+smart+body+fat+scale
I’m trying to get down under 20%. My lean body mass is 179 lbs (giving true definition to the phrase ‘big boned’!). 🙂
That’s fantastic to hear about your progress! Yes, those impedance body composition machines sometimes need calibration (and you also need more than one reading, to make sure it wasn’t a fluke, or if you didn’t have good contact between the machine and the soles of your feet/hands the first time). Best of luck with toning! Building muscle (as I was told) is the best way to maintain your weight/improve your body composition!
p.s., did you get claustrophobic the first time you dunked your head? I remember I went up before he knocked on the tub cos I suddenly felt like I was drowning! xD
Woohoo! So happy for you, Lindsay! All your hard work and dedication has totally paid off.
You should inform your doctor of your newest results so maybe he can consider improving the method he’s using to measure body fat. More accurate measurements will benefit all his patients.
I just received today the Eat Smart weight scale that Scott gave mentioned that he uses. I ordered it from Amazon based on the amazing reviews and am already impressed with the metrics it is including body fat %, bone weight, total body water %, and muscle %. Very awesome, you should look into it!
So I also have one of those Tanita BodyComposition scales, and not only does it have to be configured with your personal stats, but there’s a magic setting for fitness or regular that dramatically changes the body fat readings. I just checked the difference on my scale, and regular mode gives me %11.7, and fitness mode gives me %5.5. I haven’t done any research as to what the modes change, but I’m curious if the scale at your doctor’s office also has this setting. If it does, I wonder if switching it would get you any closer to your hydrostatic measurements. For comparison, I also have fat measurement calipers and they measure me somewhere between %8.4 and %10.6.
I think it’d be awesome if we could figure out what combination of home tests could get us close to the golden hydrostatic standard. Even if it was within 1-2% margin of error, that could be enough for us to track ourselves in between dunks.
Taking the calculations to an accuracy of 0.1 is misleading:
Body Fat: 32.85 lbs, 23.5%
Lean Body Mass: 107.35, 76.55%
because the measurements are not likely accurate to better than 2-3% at absolute best, and probably may be no better than 10% accurate.
But it’s more accurate than a body fat scale, don’t you think?
Well, I got a hydrostatic test and it had me come in at 31% Everyone is like no way. I have been doing crossfit for like 4 years and am in the best shape of my life. I DO look at myself in the mirror and I don’t see how in the world I can be 31%. I get comments all the time about how fit I look and how do I get my arms to look good! Just trying to say it’s not just me wondering. It’s like what you were feeling at your doctor’s.
This particular vendor also has me targetting a fat % in the mid 20’s, like 25%, as optimum and I’m like WHAT?? I used to have 18% and now I’m aiming for 25%?? So I am thinking of going to a different vendor and getting a second opinion.
Wow that is crazy. I don’t know what you look like, but based on what you just described I’d say go get a second opinion. Let me know how it turns out!
The hydrostatic results read air in the lungs as body fat. It’s completely possible that you did not push all the air out of your lungs during the testing and that read into your measurements. I would suggest testing again trying to push more air out of your lungs during the testing.
Thanks for sharing! I live in the South Bay too and really want to get this done! Looks like they’ll be nearby soon! I’m definitely going to do it 🙂
Awesome! Let me know how it goes 🙂
Biggest take away here is that the free navy calculator was only off by .5%. I wonder if it scales to this level of accuracy across the rest of the population.