Techniques of body composition assessment: A review of laboratory and field methods

Body composition is one of the major health-related components of fitness. Thus, it is important for health and fitness professionals to have a genera l understanding of the most commonly used techniques for assessing body com position. This review presents the developmental background and underlying principles and theory of four laboratory (hydrodensitometry, air displaceme nt plethysmography, isotope dilution, and dual-energy x-ray absorptiometry) and four field (bioelectrical impedance analysis, near-infrared interactan ce, skinfolds, and anthropometry) methods of body composition assessment. I n addition to a description of the methods, the validity, and reliability, strengths, and limitations of each measurement tool are examined. Highlight s of the laboratory methods include the relatively new Bod Pod(R) air displ acement device, which is a promising assessment tool more convenient than h ydrodensitometry but still lacking substantial validity testing and the abi lity of dual-energy x-ray absorptiometry to measure regional composition ma king it an attractive method for clinicians. Advancements in segmental and multifrequency bioelectrical impedance for compartmental analysis have enha nced the value of this field method, but research continues to show that co mmercially available near-infrared interactance units are invalid. With thi s knowledge, the clinician and researcher should be able to make an informe d decision regarding the most appropriate measurement device for their body composition assessments.