Does a Physical Education Bout Alter Percent Body Fat and the Adiposity Health Risk Classification When Using Leg-to-leg Bioelectrical Impedance Analysis in Girls?

Purpose: The purposes of this investigation were to determine: 1) whether a structured in-school physical education exercise bout altered percent body fat (%BF) determined by leg-to-leg bioelectrical impedance analysis (LBIA); and 2) whether the potential exercise-induced %BF magnitude of change altered the health risk classification of the child. Methods: Seventy-six girls (age: 12.2 ± 1.0 yr; height: 153.9 ± 7.5 cm; body mass: 51.9 ± 15.5 kg; BMI: 21.7 ± 5.4 kg/m2) participated in this investigation. LBIA measured %BF values were obtained immediately before and within five minutes after completing a structured, in-school, physical education class. Results: Significant reductions (p \u3c 0.0001) in mean %BF (25.0 ± 10.2 vs. 24.4 ± 10.3 %) were observed for the group following the physical education class. For the majority of the girls (88%), the %BF alteration was less than ± 2.0 %BF. More specifically, the %BF magnitude of change was ± 1.0 %BF in 64.5% of the girls, between 1.1 and 2.0 %BF in 23.7% of the girls, and by more than 2.0 %BF in 11.8% of the girls. Regardless of the %BF magnitude of change, all girls remained in the same adiposity classification category (healthy vs. unhealthy body fat) following exercise. Conclusion: Adhering to the pre-test exercise guideline appears unnecessary when using LBIA to categorize the health risk of an adolescent girl