Final answer:
For accurate skinfold measurement, the skinfold should be lifted enough to include the skin and adipose tissue but exclude the muscle, without specifying a millimeter distance.
Step-by-step explanation:
When performing a skinfold measurement (SKF) with calipers to assess body fatness, the skinfold should be lifted enough to include two thicknesses of skin and the underlying adipose tissue, but not the muscle. There isn't a specific distance in millimeters to lift the skin; it should be just enough to get a valid pinch. A health professional commonly uses this method by measuring the thickness of skin at various parts of the body like the back or arm and compares the results to standards to estimate fat mass. It's crucial that the caliper is placed perpendicular to the fold, and the measurement is taken about one second after the caliper's pressure is released, ensuring accuracy and reliability.