I took the plunge this morning - literally - by participating in a voluntary hydrostatic test for body fat percentage. I've long thought that although my weight is typically at the high end of the "healthy" range, that I'm fit and have a fairly dense body (read: must have lower body fat than some couch potato who weighs the same). I still think that BMI is completely inaccurate for many people, myself included, and does nothing to take fitness into account. So to test this theory, and also to give myself a starting point to gauge fitness, I did the hydrostatic test.
First, I had to fast for something like 8 to 10 hours. I wrote down these instructions and lost them. I had a beer at 11 pm last night. The test was at 5:45 this morning. Probably can't blame too much on the lack of strict adherence to the instructions.
Second, I took off all my jewelry and put on a swimsuit. The technician weighed me (air weight: 165 lbs) and measured my height very carefully (5 feet 7.25 inches, Mom). Then we went into a small room with a raised platform with a tub in it - the tub was maybe 5 feet cubed. It had a white wire cage in it, submerged, that was suspended by a cable from the ceiling. The top and sides of the cage were open, so really it was a wire floor with corner supports. I climbed into the tub and got into the cage, sitting on the floor with my toes against the far corners. I held on to the corners with my hands. I inhaled, exhaled all the air I could, and stuck my head underwater. Apparently the whole thing has to stop moving for 1 second for them to get a reading. It probably took 10 seconds. We did this three times.
After exiting the cage, we sat down at the computer and the technician entered all the info into a forumula: age, air weight, height, gender, water weight. The three readings from the cage all were the same: -.2. I'm not sure what the units are. Anyway, it spat out my percent body fat at just over 36%. Thirty-six percent! I was/am shocked. I realize I'm not at my lightest (but also not at my heaviest), and I'm not at my fittest (but not at my most sluggly), but that percent body fat put me in the bottom 10 percent for their distribution. "Very Poor" is my category. The formula also gave me the lean muscle weight and the fat weight: my fat weight is almost 60 pounds.
The technician ran the numbers to see how I'd need to tweak the formula to get "average" body fat percentage (24%). I'd need to weigh 136 pounds. This seems completely unreasonable. But, that's what I've said about BMI. I suppose at some point I'll need to recognize that all of these measurement tools can't be wrong. I don't think I want to be 136 pounds. But I do see that I need to get back on we*ght watch*rs and step up my aerobic program, which is fairly nonexistent at this point. Drinking tropical cocktails and eating chocolate-covered macadamia nuts certainly hasn't helped the last two weeks.
So, it's back on plan, starting today. I'll have to do this dunk tank thing again at the end of the winter and hopefully see some progress.
