The Body Fat Truck will be at Tamalpais CrossFit on August 23rd. This is a state of the art measuring tool that will tell you what your body is made of, not just how little fat you have but also your Resting Metabloic Rate. Below is some information on the process, please view the Mens Sample Report to see all the information you will receive with the test.

The cost is $49 please bring cash or check (you will pay him directly) day of and sign up on the sign up sheet located at the gym to reserve your spot before they are all gone!


Body Fat Test provides hydrostatic (underwater) body composition analysis. According to university research, hydrostatic weighing is the GOLD STANDARD to which all other body fat testing methods compare their degree of error. This includes calipers, bioelectrical impedance, the Bod Pod, and others.

During the test, you will totally submerge yourself comfortably warm water, heated between 89o and 94o, for only a few seconds. You are in complete control. You need to bring a swimsuit and a towel. We have private dressing rooms on board.

Eating within 2 hours before the test may affect your results by up to 1½%, but no more. Therefore, we advise you not to eat within two hours before the test. Working out and drinking water is alright. You should try to use the restroom and take a shower if possible. Also, please do not have large amounts of makeup or hair gel on when testing.

The water is chemically treated for cleanliness, similar to a swimming pool or spa, and is run on a constant filtration system throughout the day. The lab is fully heated in the winter and air conditioned in the summer to provide a comfortable testing environment.

A trained technician will be with you every second of the test. You will have privacy and confidentiality during the entire test, which only takes 10 minutes. You may have a friend in the clinic at the same time observing if you wish.

After the test, you will receive a 4-page printout, which includes your body composition including body fat percentage, lean mass percentage, resting metabolic rate, and caloric expenditure tailored specifically for you.