Skin folds on the CKD
As with the scale on the CKD (see above), to get the most out of caliper measurements, it
is recommended that they be taken at consistent times during the week. Although fat cells
contain very little water, changes in hydration level (especially water under the skin) does seem
to affect skinfold readings. Comparing a set of measurements taken on Monday to another set
taken on Friday may give inaccurate results. Rather, measurements taken on Monday should be
compared to measurements taken on the following Monday, measurements taken on Friday to
measurements taken the following Friday. Some tips for getting the most out of skinfolds on the
CKD appear below (guidelines for pre-contest bodybuilders appear in chapter 30).
- Weigh and take skin folds the morning of the last low-carbohydrate day of the week. This will
show a dieter at their leanest and give the lowest bodyfat percentage and body weight (if they use
the equations). - Measure skinfolds and weight the morning after the end of the carb-loading phase. Due to
shifts in water weight, and depending on the changes in water under the skin, this will give the
highest skinfold measurements and body weight.
Selecting calipers
Calipers vary greatly in price, quality and accuracy. The inexpensive one-site click-type
calipers (which click to indicate when the measurement is made) have proven to be inaccurate.
Oftentimes they show no change in skinfolds when other, more accurate sets of calipers show
obvious changes. They are not recommended.
The most expensive, and most accurate caliper is the Lange caliper. However, it is cost
prohibitive for most people. A good choice for a home caliper is the Slimguide caliper available
from many different sources (see appendix 2 for resources). Its measurements agree quite
closely with Lange calipers but at about one fourth the cost (approx. $30-40).
The Tape Measure
Many individuals will not have access to the equipment necessary to get accurate body
composition measurements. In this case, a very rough estimate of changes in body composition
can be made by using a measuring tape.
As with the scale and skin fold measurements, the tape measure should be used at a
consistent time of the week, generally when weight is measured. Typical sites to measure are:
Chest: taken at nipple level
Arms: taken in the middle of the arm
Abdomen: taken at the level of the belly button
Hips: taken at the largest diameter of the buttocks
Thigh: taken halfway between the knee and where the thigh joins the hip
Calf: taken at the largest diameter of the calf