Body Composition Flashcards
Healthy range of body fat (males)
12-18%
Healthy range of body fat (females)
18-23%
Hydrostatic Weighing
Calculates density of body by immersing person in water and measuring amount of water displaced.
Uses a calculation based on Archimede’s principle
Most widely used lab procedure to determine body density
Limitations: need to account for residual lung volume during submersion, patient must tolerate submersion
Standard error = 2-2.5%
Plethysmography
Method of calculating body density using the amount of air displaced during testing within a specialized closed chamber
Anthropometry (Skinfold Measurement)
Determines overall body fat % based on measurement at 9 standardized sites.
Theory: amount of subcutaneous fat is proportional to total fat in body.
Limitations: Need experienced examiner; variance of standards based on gender, age, ethnicity
Standard error = 3% with appropriate technique and equipment
Skinfold measurement procedure
- Measurements taken on right side
- Take multiple measurements at each site, retest if the difference is 1-2 mm
- Calipers 1 cm away from examiner’s fingers, perpendicular to skinfold, centered between base and top of fold
- Wait 1-2 seconds before reading caliper
- Maintain pinching of site while reading caliper
Bioelectrical Impedance Analysis (BIA)
Uses small electrical current and measures the resistance or opposition to current flow.
Based on principle that resistance is inversely related to composition of water within the body
height squared/resistance
Standard error = 3%
Limitations: Subject must be properly hydrated, must follow protocol (no eating/drinking 4 hours prior, no vigorous PA 12 hours prior, urinate 30 minutes prior, avoid ETOH 48 hours prior, avoid excessive water intake prior)
Most accurate body composition measurement method:
Hydrostatic weighing (error = 2%)
