Articles on body assessment

Technical writing for people who assess: protocols, formulas, bioimpedance and good measurement practice, with the source of every formula.

• Are bioimpedance scales accurate? What the studies showAre bioimpedance scales accurate? What studies show about repeatability and error, what changes the reading and how to standardize measurements to compare.4 min read
• Bioelectrical impedance: what it is and how it worksBioelectrical impedance: what it is, how an electrical current estimates fat-free mass and body fat, resistance, reactance, device types and precautions.4 min read
• Bioimpedance vs skinfolds: which to use in a body assessmentBioimpedance vs skinfolds: what each method measures, what it depends on, how large the error is and why results from the two should never be mixed.4 min read
• Body circumferences: how to measure them in a body assessmentHow to measure body circumferences in a body assessment: trunk and limb sites, tape technique, skinfold-corrected girth and how to compare assessments.5 min read
• How to calculate 1RM: Lombardi, Brzycki and Epley formulasHow to calculate 1RM from a set taken to failure: the Lombardi, Brzycki and Epley formulas, a worked example, and when the estimate stops being reliable.5 min read
• How to calculate body fat percentage with skinfold calipersHow to calculate body fat percentage with skinfold calipers: picking a protocol, measuring the folds, body density, the Siri equation and a worked example.4 min read
• How to do a complete fitness assessment: step by stepHow to do a complete fitness assessment, step by step: screening and history, weight and height, skinfolds or bioimpedance, girths and reassessment.4 min read
• Ideal body fat percentage: chart by sex and ageIdeal body fat percentage by sex and age: the Gallagher (2000) chart for women and men aged 20 to 79, where the numbers come from and their limits.4 min read
• Jackson & Pollock 3-site vs 7-site skinfold: which to chooseJackson & Pollock 3-site or 7-site skinfold? Accuracy is similar. See what changes in practice, both calculations on one client and why not to switch.6 min read
• Jackson & Pollock 7-site skinfold protocol: formula and calculatorJackson & Pollock 7-site skinfold protocol: equations for men and women, measurement sites and a worked example to calculate body fat percentage.4 min read
• Max heart rate and heart rate reserve: how to calculate themHow to calculate max heart rate (220 - age, Tanaka, Gellish) and heart rate reserve, with training zones by the Karvonen method and a worked example.4 min read
• Skeletal muscle mass: how to calculate it with the Lee equationHow to calculate skeletal muscle mass with the Lee equation: skinfold-corrected girths, the formula in full, a worked example and the limits of the method.5 min read
• How to calculate VO₂max: Cooper test and Rockport walk testHow to calculate VO₂max in the field with the Cooper 12-minute test and the Rockport 1-mile walk: protocols, equations, worked examples and limits.5 min read