Body fat measurement ,18 year old versus 60 year old

[Ron Murphy]

Wy is there such a big difference in body fat measurements in regards to age. If a person measures an average of 15 MM, if he was 18 he would be 8.5% bf on the gym charts, if he was 60 he would be over 18% bf. If the 60 year old is fit ,working out hard on a regular basis why is there such a big difference. Some 60 years could in better shape than the 18 year old.

[Chris Goodrich]

I believe older people tend to have more intra-abdominal fat, so even if the skin fold measurements (and therefor subcutaneous fat levels) are the same between a younger and an older person, the older would be expected to have more overall fat. That said, all BF measures are fairly inaccurate and don't account for individual variations well, so why sweat it?

[Craig Van De Walker]

This is the reason why body fat testing is not an exact science! The test is just kind of a neat tracking tool for gains or losses in the same person IF testing method/skill etc of tester are consistent. If not all bets are off.

Reasons behind age norm differences in the formulas:
-Intra-abdominal fat
-less bone mass and the porous bone is filled with marrow=fat
-intramuscular fat
-less collagenous(sp?) structure hence the calipers squish together better and move the fat to the side on the average 60 y/o(compared to an 18 y/o)
Probably something else I forgot but these are the reason's I remember for the changes in the formulas.

The above are changes that happen on average to people as they age. The average person is sedentary and has a poor diet so these are not necessarily reflective of a fit individual. Look at Skip Chase I am sure he would throw the age adjusted norms way off on a skin fold.

Track performance! Relative strength etc...

[Matt DeMinico]

I think old folks skin is thinner, but don't quote me on it. So thinner skin measuring the same thickness on a body fat measurement means there's more fat and less skin than a young whippersnapper.