Guessing bodyfat

[Donald Duck]

Hey evrybody. Wanna give some advice to all out there that is always on about bodyfat.

Here is the best way to calculate it. All you need is a caliper and somebody to help you with the measurements.

6 Skin fold Measurement

The 6 sites where you take the measurements:

Abdomen: A vertical skinfold taken 2cm lateral to the imbilicus

Thigh: A vertical skinfold taken midway between the hip and knee joints on the front of the thigh

Triceps: A vertical fold taken halfway between the acromial(shoulder) and olacranon(elbow) process

Suprailium: A diagonal fold taken anterior to the ilium(hip bone)

Subscapula: A diagonal fold taken below the middle of the lower crest of the scapula(shoulder blade)

Medial calf: A vertical fold taken at the widest part of the medial side of the leg

Once you have done that, use these 2 formulas to calculate your bodyfat:

Women: 6SF(sum of 6 skinfolds)x0.1548+3.585

Men: 6SF(sum of 6 skinfolds)x0.1051+2.58

The time for guessing you BF is now gone.

[Phedder]

All you need is a caliper and somebody to help you with the measurements.

What type of caliper, how accurate is it? Does it measure to every 2mm, every 1mm, every 0.1mm? How experienced is that somebody, have they ever used a caliper before, do they know where and how to grab the correct sites? How long should they hold the caliper on the site before reading the measurement? How do they know when they're only grabbing the skin and fat, or when they're grabbing some muscle as well?

Once you have done that, use these 2 formulas to calculate your bodyfat:

Women: 6SF(sum of 6 skinfolds)x0.1548+3.585

Men: 6SF(sum of 6 skinfolds)x0.1051+2.58

How were these formula constructed? What type of population was used to form the data set? Young athletes, sedentary middle aged, elderly, Americans, Europeans, Africans, Asians?

The time for guessing you BF is now gone.

Don't be mistaken, calipers are just another way of guessing. Everything about skinfold testing is based on assumptions. How can you possibly know for certain when something is based on assumptions?

Skinfold testing is a great tool, don't get me wrong here. It's a fantastic way to track progress, especially if you're being consistently measured by the same person, using the exact same sites and the exact same formula every time. You get tested by person A at time 1, and calculated at 16%bf, you get tested again by person A at time 2, and calculated at 12%bf. You can be fairly confident that you have reduced the amount of bodyfat you have. Perhaps not exactly by 4%, but likely something close to that. You cannot, however, be certain that you were in fact 16%bf at the first measurement, and 12%bf at the second measurement. Those numbers are based on assumptions gathered from data sets, as well as assumptions on the accuracy and consistency of both the tools and the measurer themselves.

What if you're measured by person A at time 1 at 16%bf, and then measured by person B, using a different method and formula 2 months later, at 17% bf. You look much better because you've been dilligently training and controlling your diet, but according to this person and their caliper and formula, you've gained 1% bf. How can this possibly be true, has all your hard work been a waste? Of course not. You look better, you've been training and eating well. But person B has used a totally different method and sites for measuring, and then applying those measurements through a different formula, which was created from a different data set population.

Unless you're getting a DEXA scan, you're always guessing. Just try to be consistent with how you're guessing :wink:

[student]

not sure what a dexa scan is, but i would imagine it measures something (not bf), then uses some formula to aproximate bf% too.

[tgzerozone]

not sure what a dexa scan is, but i would imagine it measures something (not bf), then uses some formula to aproximate bf% too.

It's a startrek type capsule that you put your ass into and then they lock you in there and then all sorts of lights and shit go on and bang! they give you your bodyfat percentage.

[Donald Duck]

To answer all your questions.

What type of caliper, how accurate is it? Does it measure to every 2mm, every 1mm, every 0.1mm?

Any caliper that measures up to 1mm would do.

How experienced is that somebody, have they ever used a caliper before, do they know where and how to grab the correct sites?

If you have basic knowledge of the human body, you would be able to find the sites. You don't need a scientist to work a caliper. I have given the exact sites.

How long should they hold the caliper on the site before reading the measurement? How do they know when they're only grabbing the skin and fat, or when they're grabbing some muscle as well?

You basically just pinch the skin with your thumb and index finger and hold the caliper for 3 seconds and take the reading.

Then your question about this measurement technique.

This formula and sites were first established by Drinkwater & Ross. This is an accepted formula.

This is not guessing, this is an estimate. There is a difference.

If you know what you're doing, it can be very accurate.

[tomleegolf]

What are ur stats Donald? Weight height bodyfat? Squat bench and deadlift maxes?Just curious

[FellowshipOfTheRon]

would have been better to just link people to the site you copied that off so they can use the calculator there instead of trying to plug stats in to that formula

good informative post though ducky

[Phedder]

To answer all your questions.

They were rhetorical, but thanks for the further explanations. It at least makes your initial post clearer.

This is not guessing, this is an estimate. There is a difference.

Semantics. An estimation can still be incorrect.

If you know what you're doing, it can be very accurate.

Generally no more accurate than looking in the mirror and guessing, or at least taking a few pictures and getting the opinions of some experienced individuals.

My point is I wouldn't put much stock in the actual numbers you get from skinfold testing. Like I said they're a great way to track progress and change, but when a skinfold test tells you you're 12.75% bodyfat, you're probably not. The numbers are also highly dependent upon the skill and consistency of the person administering the test, and the formula they're using. Different tester, different measurements. Different formula, different results.

[Donald Duck]

My stats. 20 years old. 98kg. Bodyfat guessing 12-14%. :grin: 1.82m tall.

Bench: 6 rep max 115kg

Squat: 10 rep max 120kg

Leg press: 10 rep max 320kg

Deadlift: 8 rep max 160kg

I can't put up a link for it. That is what I was taught in class. Believe it or not, I have a diploma in exercise science. :shock:

I agree that measuring bodyfat isn't accurate, but If done properly and with consistency, is better than guessing in my opinion.