NCSF Sport Nutrition Specialist Certification Practice Test – Complete Exam Prep

Bioelectrical impedance is influenced by hydration status because it measures body composition based on the resistance of electrical flow through body tissues. When an individual is dehydrated, the amount of water in the body decreases, which increases resistance and can lead to an overestimation of body fat percentage. Conversely, overhydration can result in lower resistance, potentially underestimating body fat. The fluctuations in hydration can cause significant variability in the measurements, making it crucial to control hydration status when using this method.

Hydrostatic weighing, while also affected by body composition, does not have the same sensitivity to hydration changes as bioelectrical impedance. Skinfold assessments rely on the thickness of skinfolds and are more directly related to the distribution of subcutaneous fat rather than fluid levels. Circumference measures provide useful information about body fat distribution but are generally not affected by hydration status in the same way as bioelectrical impedance. Thus, bioelectrical impedance is the method most significantly impacted by changes in hydration status.