Girth measurements

Girth measurements are body circumferences measured with a tape around the torso and limbs.^{1Ozemek et al., ACSM’s Guidelines for Exercise Testing and Prescription, 12th ed., p. 179.} They show the general distribution of body fat; fat carried on the trunk raises the risk of hypertension, metabolic syndrome, type 2 diabetes and cardiovascular disease more than fat on the hips and thighs.^{1Ozemek et al., ACSM’s Guidelines for Exercise Testing and Prescription, 12th ed., p. 179.}

The NSCA’s strength and conditioning protocol measures the chest, right upper arm, right forearm, waist, hips, right thigh and right calf with a flexible, spring-loaded tape.^{2Haff and Triplett (eds.), Essentials of Strength Training and Conditioning, 4th ed., p. 304.} ISSA describes girths as a way to track body composition changes, but a circumference can’t separate lean mass from fat mass.^{3International Sports Sciences Association, Strength and Conditioning, p. 185.} Helms and colleagues note that girths can show a body part growing across seasons if body fat is about the same at each comparison.^{4Helms et al., The Muscle & Strength Pyramid: Nutrition, 2nd ed., p. 189.}

In practice

• Place a flexible, inelastic tape on the skin without compressing it.^{5Ozemek et al., ACSM’s Guidelines for Exercise Testing and Prescription, 12th ed., p. 180.} With a spring-loaded Gulick tape, extend the handle to the same mark each time.^{5Ozemek et al., ACSM’s Guidelines for Exercise Testing and Prescription, 12th ed., p. 180.}
• Measure each site twice, rotating through the sites rather than repeating one immediately.^{1Ozemek et al., ACSM’s Guidelines for Exercise Testing and Prescription, 12th ed., p. 179.},^{5Ozemek et al., ACSM’s Guidelines for Exercise Testing and Prescription, 12th ed., p. 180.} Retest if the readings differ by more than 5 mm.^{1Ozemek et al., ACSM’s Guidelines for Exercise Testing and Prescription, 12th ed., p. 179.},^{5Ozemek et al., ACSM’s Guidelines for Exercise Testing and Prescription, 12th ed., p. 180.}
• Standardize posture and measurement sites.^{4Helms et al., The Muscle & Strength Pyramid: Nutrition, 2nd ed., p. 189.} Helms and colleagues measure weekly on the same day and favor a self-tightening tape because tape pressure alters the reading.^{4Helms et al., The Muscle & Strength Pyramid: Nutrition, 2nd ed., p. 189.}
• Seeing inches come off can improve exercise adherence, according to the NSCA.^{6Schoenfeld and Snarr (eds.), NSCA’s Essentials of Personal Training, 3rd ed., p. 534.}

Where should you measure the waist?

Protocols place waist circumference at different sites.^{5Ozemek et al., ACSM’s Guidelines for Exercise Testing and Prescription, 12th ed., p. 180.},^{2Haff and Triplett (eds.), Essentials of Strength Training and Conditioning, 4th ed., p. 304.},^{3International Sports Sciences Association, Strength and Conditioning, p. 185.} ACSM uses the narrowest part of the torso, between the navel and the bottom of the breastbone.^{5Ozemek et al., ACSM’s Guidelines for Exercise Testing and Prescription, 12th ed., p. 180.} It also notes a suggested site just above the iliac crest, though the formulas it discusses aren’t built on that site.^{5Ozemek et al., ACSM’s Guidelines for Exercise Testing and Prescription, 12th ed., p. 180.} The NSCA’s strength and conditioning text and ISSA measure at the navel.^{2Haff and Triplett (eds.), Essentials of Strength Training and Conditioning, 4th ed., p. 304.},^{3International Sports Sciences Association, Strength and Conditioning, p. 185.}