O impacto da quantidade de aulas de educação física na variabilidade da frequência cardíaca em adolescentes do sexo masculino: estudo transversal

Abstract

Heart rate variability (HRV) is a noninvasive and effective measure used to identify cardiovascular risk in several populations. Previous studies have shown a positive relationship between HRV and physical activity among adolescents, indicating that a higher habitual physical activity level is related with higher HRV, regardless of obesity and hypertension. However, no study analyzed the association between HRV and participation in physical education classes, environment with the possibility of physical activity practices. This research may strengthen the idea that school physical education contributes to improve the health of adolescents, especially males who are more exposed to cardiovascular risk than girls. Therefore, the present study aimed to investigate the impact of physical education classes on HRV parameters in male adolescents. The study included 1152 male adolescents (16.6 ± 1.2 years). Participation in physical education classes was evaluated, being divided into: 0 classes, 1 class and ≥2 classes; the parameters of HRV in the time domain (SDNN, RMSSD, pNN50) and frequency (BF, AF), arterial pressure and waist circumference of adolescents were also evaluated. A comparison of means with ANOVA was performed to analyze HRV parameters and physical education classes. There was no statistically significant difference regarding the number of physical education classes per week with the HRV parameters in the time domain: SDNN (0 classes = 62.5 ± 23.7; 1 class = 62.1 ± 23.9; ≥2 classes = 61.2 ± 23.1 [p = 0.77]); RMSSD (0 classes = 54.7 ± 28.9; 1 class = 53.8 ± 28.4; ≥2 classes = 55.3 ± 30.1 [p = 0.72]); PNN50 (0 classes = 29.3 ± 20.0; 1 class = 29.1 ± 20.1; ≥2 classes = 29.1 ± 20.1 [p = 0.83]); and in the frequency domain: BF (0 classes = 53.2 ± 16.0; 1 class = 53.3 ± 15.4; ≥2 classes = 52.3 ± 15.4 [p = 0.61]); PA (0 classes = 46.8 ± 16.0; 1 class = 46.8 ± 15.4; ≥2 classes = 47.7 ± 15.4 [p = 0.61]); and BF / AF (0 classes = 1.46 ± 1.1; 1 class = 1.46 ± 1.1; ≥2 classes = 1.40 ± 1.0 [p = 0.60]). It was concluded that physical education classes are not associated with HRV in male adolescents, showing little impact on the integrity of the Autonomic Nervous System, consequently on the cardiovascular health of adolescents.