INTRODUCTION:
It is known that excess weight interferes with the daily physical performance of adolescents and consequently, in physical adaptation and cardiorespiratory capacity.
OBJECTIVE:
The study aimed to identify and compare the cardiorespiratory variables at the ventilatory anaerobic threshold (VAT) of normal weight and overweight adolescents.
METHODS:
The sample consisted of 140 adolescent students of both sexes, aged between 10 and 14 years, in the city of Vitória, ES. Body weight and height were measured, to calculate the body mass index (BMI). The adolescents were divided into normal weight group (NWG) and overweight group (OWG). A resting electrocardiogram was performed, and a cardiopulmonary exercise test on a treadmill (Inbrasport Super ATL) using a MedGraphics Corporation ergospirometer and the ramp protocol. The VAT was identified by the V-slope method and/or ventilatory equivalent of oxygen (VE/VO2). The following variables were analyzed in the VAT: oxygen consumption (VO2VAT ml.kg-1.min-1), heart rate (bpm HRVAT), percentages of maximum oxygen uptake (%VO2maxVAT) and maximum HR (%HRmaxVAT) and speed (VelVAT km/h), as well as maximum oxygen uptake (VO2maxml.kg-1.min-1) and maximum heart rate (HRmax). The Student's T-test was performed for comparisons between groups, considering p <0.05 for statistical significance.
RESULTS:
The NWG was significantly higher in VAT for VO2ml.kg-1.min-1 (20.0 ± 6.4 vs 15.8 ± 5.7) and speed (7.1 ± 0.9 km/h vs 6.2 ± 1.1 km/h), and VO2max (44.6 ± 7.6 vs. 36.0 ± 6.4) compared to the OWG.
CONCLUSION:
The data suggest that overweight adolescents have impaired cardiorespiratory fitness not only at the maximum level, but also at submaximal level (VAT), compared with normal weight adolescents.
oxygen consumption; adolescent; physical fitness; anaerobic threshold
