Which statement accurately reflects BMI measurement guidelines for athletes?

• A. Height should be measured without shoes, the athlete should wear minimal clothing, and a regularly calibrated scale should be used; BMI < 18.5 kg/m2 indicates underweight
• B. Height should be measured with shoes on; the athlete should wear heavy clothing; a miscalibrated scale should be used
• C. BMI is not used in assessing athletes
• D. Preadolescent athletes should have BMI evaluated routinely

Answer: (A)

Accurate BMI assessment hinges on proper measurement conditions and understanding what BMI indicates. Height should be measured with shoes off and minimal clothing so measurements reflect true stature. Weight must be taken on a regularly calibrated scale, with the athlete in light clothing and no heavy items, to avoid systematic errors. BMI is calculated as weight in kilograms divided by height in meters squared, and a BMI below 18.5 kg/m^2 is the standard threshold for underweight in adults. This threshold serves as a consistent flag, though in athletes with substantial muscle mass BMI can be less reliable on its own and should be interpreted within the broader clinical context. The other statements either introduce measurement errors (height with shoes on, heavy clothing, or a miscalibrated scale) or misrepresent BMI use in athletes (BMI being unused or routine pediatric evaluation without noting age-specific interpretation).