About 2 1/2 weeks ago I got my bf% measured at 21.5% Since than I have been eating very clean and doing cardio 3-4 times a week. They used calipers to measure.
Now fast forward 2 1/2 weeks I get tested again at a different gym and with a different machine that I hold about eye level with my thumbs up and hold for about 15 seconds. It reads 15.4% Would there be that much of a difference?
I'm very confused, but would like to get an accurate reading. The trainer today told me that exact measurements use under water testing and a few different methods.
-Joey
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Thread: 6% loss in 2 1/2 weeks?
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07-24-2007, 05:54 PM #1
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6% loss in 2 1/2 weeks?
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07-24-2007, 06:16 PM #2
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no offense but there really needs to be a sticky about bodyfat readings and machines...
a machine does NOT know your body composition, ronnie coleman could step onto one during a competition and being 260lbs it could probably give him a 20-25% bf reading when in fact he'd be around 4! they are almost as inaccurate as asking a random person off the street for a visual guess.
if u want a half decent reading use calipers, and get it done by the same person at the same sites, for consistency.My journal http://forum.bodybuilding.com/showthread.php?t=5662511
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07-24-2007, 07:57 PM #3
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Whatever method you chose, use THAT method and stick with THAT method. Be consistent. Even if it's not perfectly accurate, you'll know what % you've lost.
I don't know what that "thing" they used on you last time was. I'm guessing it may have used electrical impedance. It sends an electric charge through your body and measures the resistance that electric charge encounters. Since muscle conducts electricity better than fat, the machine can gauge how much of your body is lean mass and how much is fat from the resistance or impedance that the electricity encounters.
I dunno why the guy above is having a hissy fit. Maybe he's thinking about Body Mass Index. Most of us know BMI is bull, but we're not discussing BMI; we're talking about body fat %. Yeah, calipers aren't exact. Yeah, electrical impedance isn't exact. But it's reasonably accurate.
I use a Tanita scale. It uses electrical impedance and a formula to calculate body fat %. Doctors and Collegiate and Professional Sports Programs use these scales too.
I'd chose the calipers or the tanita and stick with that method.ISSA Certified Trainer and Bestest Member.
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07-24-2007, 07:57 PM #4
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07-24-2007, 08:19 PM #5
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The apparent huge drop is due to inaccuracy and inconsistency between measurement methods. Each method has its merits and flaws. Futhermore, each method has its own margin of error (i.e., up to roughly 3-5% +/- with skin fold calipers). Now, when you attempt to compare measurements ascertained from two different methods, your margin of error only increases.
I agree with ShreddedOne...stick with one method. Even with the margin of error, at least you have a baseline from which you can compare future measurements against, using the same method, same margin of error, and in the process increase reliability. The Tanita Scale is awesome, and I would recommend that method. If that is not an option, then stick with calipers...preferably having the same person perform your measurements. Finally, some of the hand-held or foot-scale based electric impedence devices are flawed tremendously due to relying heavily upon upper or lower body measurements, respectively...pending a hand-held vs. foot-scale device.
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07-24-2007, 08:24 PM #6
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Oh and one more thing to add here...how much weight did you lose in that 2 week period? You would have to lose 12lbs of fat in that two week period to drop your BF% by 6 points. If that were possible, you would ultimately have lost more than 12lbs, because you would have lost some water your body was retaining, and not to mention lean mass. In essence, my point is that if you look at this logically, there is no way you dropped 6 percentage points of bodyfat in 2 weeks. I commend you on your quest to lean out and live a healthy lifestyle. Good luck in your quest to meet your goals.
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07-24-2007, 09:55 PM #7
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07-24-2007, 11:20 PM #8
- Join Date: Jan 2005
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Oh I agree 100% I realize that using the same method is the best way. I simply asked for a measurement and he pulled out his little device. I was skeptical, but figured I had nothing to lose.
I realize now that these various methods have there flaws, and that you should stick to the same method throughout your training. I will go back to the original method in about 2 weeks and see what comes up. Even though I just joined the gym down the street.
And to respond to DJINN
I knew that my reading was too good to be true. I think most people should be aware that sticking to one method is the best way. Try to stay as consistent as possible. Hopefully one day I will lose 6% bf.
And on another note: It would be a good idea to make a sticky about something like this, and make everyone aware. I mean this is what we all are here for right? To educate one another, and help everyone here achieve there fitness goal.Check out my fitday. Started as of 7/17/07
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