Effect of Exercise Intensity on Percent Body Fat Determined by Leg-to-Leg and Segmental Bioelectrical Impedance Analyses in Adults

Abstract

PURPOSE: We examined the impact that cycle ergometry exercise had on percent body fat (% BF) estimates when assessed using either leg-to-leg or segmental bioelectrical impedance analysis (LBIA; SBIA) and whether the intensity of the exercise bout impacts the %BF magnitude of change. METHOD: Seventy-four college-aged adults participated in this study. Participants visited the laboratory on three separate occasions. Testing included two 30-min exercise sessions (70% HR(max) and 85% HR(max)) and a 30-min no-exercise session, which served as the control. RESULTS: Following exercise, significant (p < .05) reductions in mean %BF were observed when using LBIA (70% HR(max) = 0.3%; 85% HR(max) = 0.5%) and SBIA (70% HR(max) = 0.8%; 85% HR(max) = 1.4%). The mean %BF reductions were significantly (p < .04) greater following exercise at the higher intensity for both analyzers. CONCLUSIONS: Our findings indicate that cycle exercise performed before LBIA and SBIA body composition assessment reduces mean %BF estimates. In addition, the %BF reductions were found to be larger at the higher end of the American College of Sports Medicine/American Heart Association recommended intensity range (85% HR(max)) and when the SBIA analyzer was used to conduct the assessment.