Once one has understood what one’s ideal somatotype is, it is necessary to calculate one’s current somatotype, as well as to identify its position on the somatotype map, so that one can then make a comparison between the two ideal and current values.

Measuring endomorphy

  As previously mentioned, endomorphy, or endomorphism, is associated with the representation of fat within the body. The greater this component, the more body fat is accumulated. To measure it, in addition to stature in cm, certain data called skin folds are required, which can be measured using a specific procedure: plicometry.

Plicometry

  Plicometry is the measurement of the thickness of panniculus adiposus in particular areas of the body. It requires the use of a special instrument called a plicometer. The plicometer takes the form of a sort of caliper with an indicator that shows a different value depending on the degree of opening: the greater the degree of opening, the greater the value marked by the plicometer. On the market, there are mechanical plicometers (with a pointer needle, as in common personal scales) and electronic plicometers (with a display). There are professional instruments that are very accurate and precise, i.e. they allow measurements close to the real value of the parameter to be assessed and are repeatable. Other, cheaper products have lower accuracy and precision. Needless to say, a high quality product is preferable for a more reliable analysis, but if these products are out of one’s pocket (a professional plicometer, such as the Harpenden, can be expensive), even a cheap product may be fine. The plicometer is used, as the name suggests, to measure (in millimetres) the thickness of the skin folds (or folds) in particular areas, known as repere points, that are sensitive to fat accumulation, such as the hips. For the purpose of calculating the somatotypical endomorphic component, skin folds measured at three repere points are required:

1. subscapularis: the plica should be taken diagonally at the inferior angle of the scapula;
2. tricipital: the plica must be taken vertically in the central region of the arm, which must be flexed;
3. suprailiac (median or anterior): the plica should be taken diagonally just above the iliac crest;

Instructions for using the plicometer now follow:

1. holding the plicometer in the right hand, locate the point of repere by grasping it between the thumb and forefinger of the left hand (vice versa for left-handers), taking care, by touch, to grasp only the subcutaneous fatty tissue (well separated from the muscular tissue);
2. Open the plicometer and place it on the selected target point, taking care that the instrument is placed perpendicular to the panniculus adiposus;
3. close the plicometer on the panniculus by letting it ‘pinch’;
4. very slowly remove the fingers from the panniculus;
5. wait a couple of seconds;
6. take a reading on the device;
7. the measurement should be repeated twice, with at least a two-minute pause between each measurement. The wait is necessary for the plica to return to its original, incomplete form;
8. If the result of the first measurement differs from that of the second by more than 10 per cent, a third measurement must be taken, again after waiting the requisite two minutes;
9. the value to be marked is the arithmetic mean of the results of the measurements taken.

The calculation of endomorphy

  To calculate endomorphy, two steps must be performed. First, it is necessary to sum up the previously measured thickness of the skinfolds:

ΣP = PSS + PT + PSI

Where ΣP is the sum of the values of the three folds, PSS is the thickness of the subscapularis plica, PT is the thickness of the tricipital plica and PSI is the thickness of the suprailiac plica. In the second step we need to calculate:

where, again, SP is the sum of the subscapular, tricipital and suprailiac folds, and S is the value of the stature in cm.

Measuring mesomorphy

  Mesomorphy, or mesomorphism, is a good measure of the amount of muscle (and bone) mass. The following data are needed to measure it:

1. diameter of the humerus (to be measured using a special gauge. Details below);
2. diameter of the femur (as above for measurement);
3. stature;
4. arm circumference;
5. calf circumference;
6. tricipital plica;
7. calf plica.

Bone diameters

  In order to measure the diameters of the humerus (arm bone) and femur (thigh bone), one needs a special caliper, which is also readily available online and rather inexpensive. The diameter of the humerus is measured at the elbow, with the elbow flexed at 90°. As for the diameter of the femur, this is measured at knee level from a sitting position with the joint in question flexed at 90°.

Circumferences

  A special metric tape can be used to measure circumferences, which, like the bone gauge, is easy to obtain and inexpensive. Alternatively, an ordinary metric tape will also serve the purpose well. These should be measured with contracted muscles at the widest point.

Skin folds

  As far as the triceps plica is concerned, we have already seen how to detect it in the part on calculating endomorphism. As far as the calf plica is concerned, this should be taken vertically, in the most voluminous region and medially (i.e. inwards). The use of the plicometer is similar to that seen in the part on measuring endomorphy.

The mesomorphy calculation

  Mesomorphy is calculated as follows:

where DG is the diameter of the elbow in centimetres, DF is the diameter of the femur in centimetres, CB is the brachial circumference in centimetres, PT is the tricipital plica, CP is the circumference of the calf in centimetres, PP is the calf plica and S is the stature in centimetres.

Measuring ectomorphy

  In order to measure ectomorphy, and, consequently, the height development of one’s body, one only needs an indication of stature in centimetres and body weight in kilograms.

The reciprocal weight index

  The measurement of ectomorphy depends on that of another value, called the reciprocalweight index. It is calculated as follows:

where HWR is the reciprocal weight index, S is stature in centimetres and BW is body weight in kilograms.

The calculation of ectomorphy

  The calculation of ectomorphy follows three different procedures depending on the value of the reciprocal weight index. In more detail, let HWR be, as above, the reciprocal weight index:

• if HWR ≤ 38.25, then the ectomorphy value is 0.1.
• If 38.25 < HWR < 40.75, then:

• If, finally, HWR ≥ 40.75, then:

Graphically representing the somatotype on the somatotype card

  To locate the position of your somatotype on the somatotype map, you need to calculate its coordinates as follows: