Your Body

Learn how to take your body measurements properly to get the most accurate data to improve your plan.

Dave @ Wellest avatar
Written by Dave @ Wellest
Updated over a week ago

How do I take my measurements?

First, why does Wellest need Body Measurements?

Wellest uses a variety of industry-standard and research-based formulas for calculating your health statistics based on your demographics (e.g. hormonal sex) and your body measurements (e.g. height). Demographics are useful because they provide a reasonable assessment for the average individual using simple and easy questions. But the further an individual is from these averages, the more important taking detailed body measurements becomes. Taking body measurements allows Wellest to know whether changes in weight are due to changes in hydration status, body fat, or lean body mass. This makes the process of tuning and refining your plan as fast as possible. And of course, over time all Wellest users will become far healthier than the average person, so having this data is always critical whether you're new to Wellest or have been using it to maintain your ideal body for years.

Body Composition

Wellest estimates body composition using the US Navy's Body Composition Assessment method, which measures an individual's height and weight, as well as neck, waist, and hips circumferences. This method has been shown to be the most time-, cost-, and skill-effective method for assessing body composition (see Slide #3).

Of course, there are a variety of other ways to measure body composition (e.g. DXA (Dual-energy X-ray Absorptiometry)). Although some of these measurements are more accurate they are also too costly or inconvenient to be assessed weekly. Because Wellest targets significant changes in your body composition each week it is critical to determine whether your body is responding as expected to your plan each week.

Sadly, the most notable choice for easily determining body composition is Bioelectrical Impedance Analysis (BIA) (most commonly used on smart weight scales) is wildly inconsistent due to variances in electrode placement, hydration status, timing of meals, ambient air, and skin temperatures.

Method

Standard

Error

Cost of Equipment

Cost per Person

Time per Person

DXA

1.0 – 2.0 %

$100k

$100 – 300

15 min

Bod Pod

1.5 – 3.0 %

$50k

$40 – 50

10 min

Hydrostatic Weighing

1.5 – 3.0 %

$50k – 75k

$50

45 – 60 min

Calipers

3.0 – 5.0 %

$125

$125

10 min

Circumference (US Navy)

3.5 %

$4

$4

5 min

Bioelectrical Impedance (Clinical)

4.0 – 5.0 %

$3k – 18k

$40

1 min

Demographics

5.0 %

$10

$10

2 min

Bioelectrical Impedance (Home)

Highly Variable

$20

$20

1 min

Genetic Potential

In addition to Body Composition, Wellest also evaluates your Genetical Potential as a key consideration for your health. Genetical Potential refers to the maximum possible Fat-Free Mass Index (FFMI) your body can achieve based on your gender and stature. FFMI is equal to the amount of your lean body mass per your height squared. FFMI is similar to the concept of Body Mass Index (BMI) except that it ignores the contribution of your Fat Mass to your Weight. Knowing how far you are from your Genetic Potential allows Wellest to determine the optimal rate of lean body mass change that is possible for you at any health status. Further, optimizing FFMI will reduce your risk of developing age-related muscle loss (i.e. sarcopenia) and bone loss (i.e. osteoporosis) as well as improving flexibility, athleticism, and aesthetics.

Wellest estimates your Genetic Potential using the methods developed in Your Muscular Potential by Casey Butt, PhD, which measures your wrist and ankle circumferences in addition to the measurements already required by the US Navy BCA.


Required Equipment

  • Weight Scale

  • Body Measuring Tape

Height

"The member will stand on flat surface, at attention, with head held horizontal, looking directly forward, with the line of vision horizontal, and the chin parallel to the deck (i.e. ground). The body should be straight, but not rigid."

Weight

The US Navy BCA rounds weight to the nearest 1/2 pound and asks members to weigh-in wearing clothes to make it faster and easier to take measurements. However, this introduces significant measurement-to-measurement variability. In addition, due to the inherent day-to-day variability of weight with hydration and electrolyte status, carbohydrate intake, exercise-induced inflammation, menstrual cycles, etc., it is important to weigh-in daily so Wellest can calculate your weekly average change to mitigate this issue. Altogether, Wellest prefers you:

Weigh yourself using a calibrated digital scale with at least 0.5 lb (1 kg) sensitivity, each morning upon waking, after using the bathroom, completely naked, to minimize day-to-day differences.

Neck

"Neck measurements shall be taken on bare skin, at the point just below the larynx (Adam’s Apple) and perpendicular to the long axis of the neck. Do not place the tape measure over the larynx. Member looks straight ahead during measurement with shoulders down and relaxed (not hunched).

The tape will be as close to horizontal as anatomically feasible (the tape line in the front of the neck should be at the same height as the tape line in the back of the neck).

Care should be taken so as not to involve the shoulder/neck muscles (trapezius) in the measurement."

Waist for Males ("Abdomen")

"Abdomen measurements shall be taken on bare skin, across the navel (belly button), and with the member’s arms down on the sides. If redness and lines in the skin are observed, turn the member away for 72 hours. This is an indication that the member has attempted to alter the BC circumference measurement.

Take measurements at the end of member’s normal, relaxed exhalation. Discourage the member from holding their breath by taking the measurement after several exhales."

Waist for Females ("Natural Waist")

"Natural Waist measurements are to be taken on bare skin, at point of minimal abdominal circumference, usually located about halfway between the navel and the lower end of the sternum (breastbone). When this site is not easily observed, take several measurements at probable sites and use smallest value.

Ensure the tape is level and parallel to the deck and make sure the member’s arms are at their sides. Take measurements at the end of member’s normal, relaxed exhalation."

Hips

"Hip measurements are to be taken over the Navy PTU shorts only. Control-top pantyhose, spandex tights, and other "shaping" garments are not allowed to be worn during measurements. Tight-fitting rubberized foundation garments or exercise belts are also prohibited at least 30 minutes prior to measurement.

Measure hip circumference while facing member’s right side by placing the tape around the hips so that it passes over the greatest protrusion of the gluteus muscles (buttocks) as viewed from the side.

Make sure the tape is level and parallel to deck (i.e. ground). Apply sufficient tension on the tape to minimize effect of clothing."

Handedness

Handedness per Wikipedia, "In human biology, handedness is the better, faster, or more precise performance or individual preference for use of a hand, known as the dominant hand." Wellest prefers to use the dominant wrist for assessing genetic potential so it is useful to know which is your dominant hand.

Dominant Wrist

Per Your Muscular Potential by Casey Butt, PhD, "wrist circumference measured on the hand side of the styloid process. (The styloid process is the bony lump on the outside of your wrist.)". Place your measuring tape in the space between this bony process at the end of your forearm and before your palm begins. This is generally the narrowest section of your forearm.

Footedness

Footedness per Wikipedia, "Footedness is the natural preference of one's left or right foot for various purposes. It is the foot equivalent of handedness." As with Handedness, Wellest prefers to use the dominant ankle for assessing genetic potential so it is useful to know which is your dominant foot.

Dominant Ankle

Per Your Muscular Potential by Casey Butt, PhD, "Ankle circumference at the smallest point". Place your measuring tape in the area above the bony process on the inside of your ankle at the end of your calf and before your ankle and foot begin. This is generally the narrowest section of your calf.

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