The Flaws of DEXA Scan

[numbere]

[kelkel]

Quite baffling.

[tarmyg]

Very interesting. This is, of course, why, at least the places I have been to, have very strict protocols to follow in the 48h leading up to a test to make sure each time is as accurate as possible.

[kelkel]

What type of protocols tarmyg?

[tarmyg]

What type of protocols tarmyg?

This is the information they gave me before the scan. They told me to document anything I am doing so I could replicate it if I wanted another scan at a later date.

• Ahead of your investigation, you should be fasting, i.e., you should not have consumed any food 6 hours before the scan. Try to have a healthy fluid balance in the body (document how much you drink and replicate for your next scan), and make sure you have emptied your bladder before the procedure.
• The survey is conducted with as little clothing as possible, and our recommendation is underwear (boxers or sports bra and panties). It is important that the clothes you want to wear do not have any metal parts such as buttons, zippers, bra straps, buckles or the like. This is to avoid incorrect measurements.
• If there is a possibility that you may be pregnant, we ask that you reschedule your time and come back when you know for sure that is not the case. If you are unsure, we recommend that you use the 10-day rule which says that an X-ray can be performed during the 10-days following the first day of bleeding.
• If you conduct an MRI, CT, X-ray contrast or nuclear medicine investigation within 7-days before your DXA scan, we ask you to postpone your DXA-Scanning until at least a week passed between the surveys.
• If you eat calcium tablets, we ask you, if possible, to wait for your daily dose until after the scan. This because they otherwise would not have time to dissolve and can interfere with the ability to analyze the measurement.
• If you're an athlete, you should make sure to be fully recuperated, i.e., have regained a healthy fluid balance before your examination. Our recommendation is to wait at least 4 hours after your last workout before undergoing the test.

[Back In Black]

The moral of the story, Go by the mirror, don't get hung up on numbers.

[Mr.BB]

The moral of the story, Go by the mirror, don't get hung up on numbers.

Errr..., when ppl start doing piss contest it is what happens.

Different machines will have different sensitivities and calibration parameters, so as in everything, there's a error factor. Also you can see surface bodyfat, but you cannot see internal fat.

Plus, if you know how an athlete looks 5 days before a show and compare it to the actual show day, and you know that all his lost is water, comparing through mirror can be really deceiving too.

[MuscleScience]

I ran a DEXA machine for a number of years in grad school. Early in the morning after a 12 hour fast give the best results for sure. When done correct by a skilled operator, they were at the time within a 3% absolute (not body fat percentage) margin of error. I would imagine 10 years later, a lot more advanced. The thing about dexa is, they were never intended to look at lean body mass. They were designed for bone density measurements. Figuring lean body mass was a good byproduct of the technology.

[kelkel]

This is the information they gave me before the scan. They told me to document anything I am doing so I could replicate it if I wanted another scan at a later date.

• Ahead of your investigation, you should be fasting, i.e., you should not have consumed any food 6 hours before the scan. Try to have a healthy fluid balance in the body (document how much you drink and replicate for your next scan), and make sure you have emptied your bladder before the procedure.
• The survey is conducted with as little clothing as possible, and our recommendation is underwear (boxers or sports bra and panties). It is important that the clothes you want to wear do not have any metal parts such as buttons, zippers, bra straps, buckles or the like. This is to avoid incorrect measurements.
• If there is a possibility that you may be pregnant, we ask that you reschedule your time and come back when you know for sure that is not the case. If you are unsure, we recommend that you use the 10-day rule which says that an X-ray can be performed during the 10-days following the first day of bleeding.
• If you conduct an MRI, CT, X-ray contrast or nuclear medicine investigation within 7-days before your DXA scan, we ask you to postpone your DXA-Scanning until at least a week passed between the surveys.
• If you eat calcium tablets, we ask you, if possible, to wait for your daily dose until after the scan. This because they otherwise would not have time to dissolve and can interfere with the ability to analyze the measurement.
• If you're an athlete, you should make sure to be fully recuperated, i.e., have regained a healthy fluid balance before your examination. Our recommendation is to wait at least 4 hours after your last workout before undergoing the test.

Thanks tarmyg. So which did you choose, boxers or bra and panties?

[wellshii]

Internal and external BF. Saw that vid last time, some looked leaner but werent.
Its like a compression test on car,more accurate than guessing or some home made gauge,but has to be calibrated and everything working right as well as set-up.
I would trust a dexa scan more than calipers or guessing simply because it measures all BF.
That is the body in whole and has to be accounted for when dieting or bulking etc.