My First Hydrostatic Weighing Experience

This weekend, I got my body fat percentage tested. To be real, I’m more of an “ignorance is bliss” type of person when it comes to weight/body fat/etc. I think these numbers can be valuable if you’re looking to reach a specific goal, but since I’m not currently going after a specific weight or body fat percentage goal, I’ve been going by how I feel. If I feel energized and my skin looks clear, I’m usually doing ok. It’s when my pants start to get tight and my face starts breaking out that I know it’s time to scale back a little and can do it in an intuitive way. Anyway, when I saw that the Body Fat Test was going to be at Orangetheory, I decided to give it a whirl. It’s been SO long (a couple of years) since I’ve had my body fat tested, and I have to admit, I was a little curious. Also, I’ve never done hydrostatic testing, which is one of the most accurate methods. (I’ve done the bod pod, caliper testing, and the handheld devices in the past.)

Hydrostatic Body Fat Test Tank

My friend Jolen (who also coaches at Orangethoery) is the new owner of the San Diego dunk truck. I was pretty stoked to get some information about my body composition, especially since I have been hitting strength and cardio consistently since we’ve lived here. I wasn’t quite sure what to expect, and as someone who gets mildly claustrophobic, I was worried that I’d be shut into a giant water tank. Thankfully, it was nothing like that.

san diego dunk truck

Here’s How the Body Fat Test Dunk Tank Worked

-I changed into my swimsuit and had my height and weight checked.

-After that, I got into the water scale, which is really like a large bathtub. The water temperature was glorious, too: 90 degrees.

Jolen and the dunk tank

-Jolen talked me through the process:

1) You strap your legs down using a weighted belt.

2) Plug your nose and deeply exhale as you go back into the water.

3) The goal is to exhale ALL of the air out of your lungs and then come back up. (So after you think you’ve exhaled everything, continue to breathe out as any air left in the body is registered as fat.) 

-After 4 times under, I was able to change and get my results.

I figured that since this method is supposed to be extremely accurate that I would get a higher number. Turns out, it was much lower than I expected (like 5% lower!). I didn’t argue with it. I took it, and ran haha. While I do prefer to go by how I feel, it’s going to be nice to have a baseline. I’d love to get tested again in 3 months or so and see how or if that number has changed.

If you’re local, Jolen’s info is here if you’d like to get tested. It’s fast, reasonably-priced ($45 for your first test and $35 for each following test) and insightful!

Other Methods of Calculating Body Fat Percentage

Calipers. This method is commonly used by personal trainers as it’s pretty straightforward and fairly accurate. The problem is that with clients who have a lot of weight to lose or significant excess skin, this method is not as dependable. Also, it’s important to make sure the same trainer tests you each time as everyone has their unique method and spots they like to pinch. (I personally prefer chest, abdominal, triceps, thigh, subscapular and Iliac crest measurements).

Scales. There are scales that use biolectrical impedance to measure body fat. This sounds scary, but all that it means is that they send a small electrical current (which you cannot feel) through your body. Fat resists this current, so the scales are able to get an idea of body fat percentage. I’ve researched around and found that they’re about 80% accurate, but various factors can impact your results, including sodium levels and dehydration. 

DEXA scans. These sound AMAZING, but they’re very hard to find. They are supposed to be as accurate as hydrostatic weighing, but also provide insight for bone density. You can read more about DEXA scans here, but the article suggests that it may be possible to get these scans at local universities for around $100. 

Bod Pod. I did this a couple of times in Valdosta on base and loved it. The Bod Pod is an air displacement plethysmograph which gives a measurement of body volume and weight. Basically, you get into a egg-shaped pod and in about two minutes, the device can estimate fat and lean mass from your volume and weight. It’s a very accurate measurement and not invasive. You wear a little swim cap, some snug-fitting clothes, and sit in the pod for a couple of minutes. Bod Pods can be a little harder to find, but are a reasonably-priced option.(On base, it was freeeeeeeee!)

Some Tips for Testing Body Fat Percentage

-Whatever method you decide to use, use the same method each time. Don’t compare caliper measurements to scale measurements to Bod Pod measurements. If you’re using the same method consistently, you’ll get a much better picture of overall progress.

-Don’t test too frequently. It can be discouraging, especially when other aspects are going well. I recommend waiting a few months before testing body fat percentage again, as little factors on a daily basis can affect this number. It will give you a better idea of overall patterns and adjustments that can be made.

-Body fat percentage is important, but a small picture of overall health. Focus on all aspects of health including a clean diet, solid fitness routine, good sleep habits, minimizing alcohol intake, and mental health.

Have you had your body fat percentage checked? What method did you use??



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  1. MW on December 10, 2014 at 10:18 pm

    I really want to have this done, but I’m terrified of water. You had me until the “go back into the water” part! 🙂

    • Fitnessista on December 10, 2014 at 10:26 pm

      it’s not deep at all! when you sit down, it only goes up to below your chest. it’s really like a giant bathtub

      • MW on December 10, 2014 at 10:27 pm

        I don’t even like to get my face wet in the shower! I’m such a chicken!

  2. Jill @ Champagne for Everyday on December 10, 2014 at 11:15 pm

    This is SO COOL! I have never felt the need to get my body fat # before, but I would 100% give this a try because it’s soo accurate and not affected by other “noise”. Have you ever done the really accurate version of the test for how many calories you burn per day?
    Thanks for sharing your experience!
    Champagne for Everyday – A San Francisco Based Lifestyle and Fashion Blog

    • Kat Gunsur on December 11, 2014 at 3:19 pm

      The great thing about the test is it gives you a 3 page report based off of your results which includes your Resting Metabolic Rate aka how many calories you burn in a day without exercise : ) Check it out!

      Coach Kat*

  3. Alex @ get big, go to work on December 11, 2014 at 3:48 am

    I’ve only ever had my body fat percentage checked with calipers. I definitely have the same mindset that health includes a lot more than just body fat % and really go by how I feel and more importantly, how my clothes fit, but this looks like a very interesting and innovative method for body fat readings. It would be really cool to see if there was something around my area that did this also. Is the dunk tank something that is franchised or something Jolen owns?

  4. Livi @ Eat, Pray, Work It Out on December 11, 2014 at 4:46 am

    We have a DEXA at my university so I’ve used it in my research, and tested myself/other students a few times! I would definitely agree that body fat % is a good tool, but not something to obsess over/have checked all the time!

  5. Lauren @ The Bikini Experiment on December 11, 2014 at 4:58 am

    Very cool! I have only done calipers in the past, but this definitely sounds worthwhile. Thanks for sharing!

  6. Kirtley @ The Gist of Fit on December 11, 2014 at 5:06 am

    Totally with you about ignorance being bliss….I don’t really care about the numbers, as long as I feel good!

    Haha and I hate getting my hair wet…I think that’s the number one thing that would keep me from trying that! It’s fun to hear about it, thanks for explaining!

    • Julie on December 11, 2014 at 8:41 am

      I couldn’t agree more – on both points!

  7. Mary Beth on December 11, 2014 at 6:30 am

    I had it checked in college usin the caliper method. It was very valuable info because I ha always thought I was borderline overweight (thanks BMI charts), but my body far said I was on the low average side. It really changed my body image. I want to get it done again since that was two years, and twin pregnancy, and 30 lbs ago. Still working on that baby weight.

  8. Megan @ Skinny Fitalicious on December 11, 2014 at 6:49 am

    I’ve always wanted to have my body fat done. Actually wish I had done it years ago before and after losing a ton of weight. Now I think the number would mess with my head. I’m too competitive with myself. That’s why I don’t weigh myself anymore.

  9. Cassie Vaughn on December 11, 2014 at 7:29 am

    I love your advice not to test too frequently. I really respect a lot of people that advice to throw out the scale, but I like having that information. However, as I continue to get healthier, happier, and my skin clears up, I feel awesome, I need that baseline less and less. I only weigh myself every 2-4 weeks, which is perfect. In fact, I normally only jump on the scale when I’m feeling yucky, bloated, and normally get the numerical reminder that I have let things slip. When I feel awesome, I don’t need it as much. Thanks!

  10. Dietitian Jess on December 11, 2014 at 7:49 am

    I did a Dexa scan in october and thought it was definitely more accurate than the handheld devices (I’ve been told that those only measure your upper body body fat %)… its interesting to find out but definitely not something to do too frequently or obsess over!

  11. kristin | W [H] A T C H on December 11, 2014 at 8:00 am

    i would love to try this. i have no idea what my body fat percentage is!

  12. Kay on December 11, 2014 at 8:06 am

    This is super interesting. I totally want to do this sometime, but I’m not sure I want to see the results. 🙂

  13. Carrie on December 11, 2014 at 8:54 am

    I’ve had my body fat % tested using the handheld calipers quite a few times. We had to have it done while I competed in college athletics (before fall conditioning, during, and after). Also, my husband and I like to test it every 3-4 months through our trainer at the gym, as we keep changing up our fitness routine. It’s fun to test it, try a different fitness approach for a while,
    and then test it at the end of that cycle to see what happened. I have found that certain routines help reduce my BF, but don’t do much for my hubby’s, and vice versa. Kind of like our own little experiment!

    Also, we normally do a 10-16 site test, rather than a 3-6 site test. It is much more accurate, especially because the 3 site test skews guys low and women high (measures where guys tend to have less fat and women tend to have more, naturally).

    • priya on December 11, 2014 at 10:33 pm

      that’s interestin! what routines had what effect?

  14. Michael Clare on December 11, 2014 at 9:03 am

    Was the % you got from calipers close to this one? I am wondering how accurate they are!

    • Fitnessista on December 11, 2014 at 9:27 am

      no, but last time i did calipers, liv was about 3 months old. maybe i’ll pinch myself and see how the numbers compare now haha

  15. Christabel on December 11, 2014 at 9:48 am

    I’ve always want to get this done but I’m pretty overweight (about 40lbs over my ideal weight). Do you think it would be really embarrassing for me? I used to see it offered through my gym a lot and figured it was for really, really fit folks. I’m definitely curious and I’d like to have a baseline as I get fitter.

    • Fitnessista on December 11, 2014 at 10:02 am

      not at all! it’s very private -much different than getting pinched, or being weighed in a room full of people- and will definitely help to give you a baseline

  16. Meagan on December 11, 2014 at 10:14 am

    I did this same test two years ago! The percentage I thought was a little high, BUT probably very accurate, and then gave me some KRAPPY recommendations in the paper work they give you, but overall it was a great experience I would do again.

    As women though, we need a bunch of body fat to function. I am much healthier now than I was 4 years ago, even though I weigh more. I think it’s good for curiosity’s sake, and if one has a good relationship with their body, but otherwise it’s kind of pointless. We all need a certain percentage of body weight to function well and get our periods, and it’s so different woman to woman. And women carry so much more natural body fat than men, so our percentages are way higher.

  17. Rebecca @ Strength and Sunshine on December 11, 2014 at 10:53 am

    In my Functional Fitness class this year, (just a few weeks ago) we went down to the lab and I got to do the BodPod! Pretty strange! I’ve done DEXA and the handheld one too!

  18. Ashley @ A Lady Goes West on December 11, 2014 at 11:04 am

    As a trainer at Equinox, we used one of the biometric scales, and it seemed very on point to me, but not everyone agreed. I haven’t checked my PBF in a few months and would love to try the hydrostatic method for sure. And calipers? No thanks!

  19. Jolen LaPerna on December 11, 2014 at 12:48 pm

    Thank you Fitnessista for the great article! I appreciate the opportunity to test you and I’ll attribute your awesome body fat test results to your great effort in class at Orangetheory Fitness and the great coaching staff. 🙂 Anyone that is interested in getting tested or setting up a testing date for the clients or at their gym feel free to contact me at

    See you soon!

    In Health,

  20. Cassy @ Wine & Dine to the Finish Line on December 11, 2014 at 2:14 pm

    I actually just met Jolen today! He’s coming to the gym I work at in UTC next Saturday for an event and I’m going to do it then. Can’t wait!

    • Fitnessista on December 11, 2014 at 4:09 pm

      no way! that is so awesome! you’ll love it 🙂

  21. Laura B @ FitMamaLove on December 11, 2014 at 2:29 pm

    I’ve had it done with a handheld and also on a scale where I held handles out to the side. I actually did the latter before and after Winter Shape Up when I was getting back in shape after having my second baby. 🙂 I’d like to do it again now because I notice my body shape changing and my weight is up and I’m having a hard time figuring out if it’s all muscle gain or if I need to balance my workouts better/watch what I’m eating more. It’s been tricky to get the right balance of workouts in since I started teaching Pilates most days of the week.

  22. Laura B @ FitMamaLove on December 11, 2014 at 2:30 pm

    Also, meant to ask what is it about your diet that makes your skin break out?

  23. Brittany Lesser on December 11, 2014 at 5:04 pm

    I’ve never had my body fat tested other than with the one that you squeeze with your hands, but I don’t think those are accurate at all haha.

  24. Amanda on December 12, 2014 at 6:36 am

    Had mine tested with the bod pod (only because the base I live near just got it and like you said, it was FREE!).

  25. Chloe on December 12, 2014 at 1:42 pm

    I interned at The Fitness Institute of TX at UT Austin (the RD there actually turned me on to your blog, so you can thank her for that lol) and we do the DEXA there for obesity and other research, along with testing the athletes 4-5x/year. I wanted to comment that in their RD’s experience, people were anywhere from 2-6% higher (on average) on the DEXA vs. hydrostatic weighing as the DEXA is currently the gold standard…when I was interning, I saw more than a couple of people get upset over their measurements being higher than what they expected them to be. In other words, you make a great case for being CONSISTENT with whatever you use to measure your body comp and at the end of the day, it’s just NUMBERS. It’s hard to quantify total health and happiness, right? 🙂

  26. Lucie@FitSwissChick on December 13, 2014 at 12:14 am

    i would love to try this! I checked my BF with the caliper so far, but lately I am just not interested so much anymore. I built a lot of muscle and I feel good – maybe when I am over in Cali I’ll go for it!

  27. Jacqueline on February 2, 2015 at 9:29 pm

    Are all body fat testing methods priced similarly? You said $45 initial was reasonable for this method, but what about BodPod or finding a PT to pinch me? Haha. I’m interested in seeing where I’m at before getting into half marathon training but want to make sure I’m not paying some obscene amount… and unfortunately, I have no one to get me access to the nearest base 🙂

  28. Jessica on November 26, 2015 at 7:54 am

    I just got my body fat dunk test yesterday in El Cajon, and it was awesome! I am in the “fair” range according to his levels (though another source online says that I’m “fitness” – go figure!) – and this is really inspirational for me as I’m trying to get more healthy and I’d like to get retested to measure my progress in 3-6 months. Jolen is REALLY friendly and I felt like he was really passionate about educating me towards reaching my goals, which went above and beyond what I thought I would be getting. Even though I don’t personally count calories, it’s also really cool to know how many calories you burn without any activity and with a long list of various activities, just based on your weight/age/gender and specific body fat %.

    • Fitnessista on November 27, 2015 at 9:18 am

      i’m so happy you liked it, and yes, jolen is awesome. excited to hear that you found it helpful! i’m going to get mine tested again in a couple of months

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