| The purpose of this investigation was to determine the effect
of intermittent sub-maximal exercise on percent body fat (%BF) estimated
by leg-to-leg bioelectrical impedance analysis (LBIA) in children.
Fifty-nine children (29 girls; 30 boys) mean age 9.0 ± 1.3 years participated
in this study. LBIA measured %BF values were obtained immediately
before and within five minutes after completing an intermittent exercise
protocol consisting of three 8-minute sub-maximal exercise bouts (2.74
km·hr-1, 0% grade; 4.03 km·hr-1, 0% grade; and 5.47 km·hr-1, 0% grade)
each separated by a 5-min seated rest period. The three exercise bouts
corresponded to 56%, 61% and 71% of maximal heart rate. Significant
differences (p < 0.001) were observed for fat mass, fat free mass,
total body water, and body weight, post-exercise in both groups. Significant
reductions (p < 0.001) in %BF were observed post-exercise in the
female (23.1 ± 9.9 vs. 21.8 ± 9. 9 %) and male (23.3 ± 10.5 vs. 21.8
± 10.2 %) children when compared to pre-exercise values. However,
for the majority of the subjects (females = 86%; males = 73%) the
decrease in %BF post- exercise was less than 2.0 %BF. These data indicate
that sub-maximal intermittent exercise, that may be representative
of daily free-form activities in children, will most likely have a
limited impact on %BF estimates when the assessment is performed immediately
post-exercise.
KEY
WORDS: Bioelectrical impedance analysis, body fat, sub-maximal
exercise, children.
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