Efeitos agudos de dois protocolos de exercício intervalado de alta intensidade no afeto, desempenho em matemática e variabilidade da frequência cardíaca em crianças

Abstract

Educational inequalities between Brazil and other countries underscore the need for greater attention to various tools capable of enhancing academic performance. High-Intensity Interval Training (HIIT) may have positive effects on the mathematical performance of children and adolescents and influence affective responses. Heart Rate Variability (HRV) is a biosignal that may exhibit manifestations correlated with potential affective changes during mathematical tasks. This is because higher HRV is associated with greater resilience of the nervous system and better cognitive performance, while lower HRV may indicate higher stress levels and lower emotional resilience. Objectives: To investigate the acute effect of two HIIT protocols on mathematical performance, autonomic nervous system, and affect in healthy children. Methodology: This is a crossover randomized trial with 23 nine-year-old children. The Positive and Negative Affective Schedule for Children (PANAS-C8), the mathematical test (MT) were conducted before and after 11 minutes of exercise. The Tabata HIIT protocol lasted 4 minutes with 8 sets of 20 seconds of effort followed by 10 seconds of rest, while the progressive HIIT protocol lasted 5 minutes, with 5 sets of 20 seconds of maximum effort followed by 30, 40, 50, 60, and 20 seconds of rest, respectively. Two-way repeated measures ANOVA and paired t-tests with Bonferroni corrections were used for multiple comparisons. Estimation statistics were also performed to evaluate the effect of exercise protocols on mathematical test, affect, and HRV, with results presented for significance (p<0.05) and effect size g (Hedge's). Results: Comparisons reveal that, after HIIT interventions, children showed a significant increase in mathematical performance, especially in the Tabata HIIT protocol (g=0.39; 95% CI 0.12 to 0.76; p=0.00), compared to the progressive HIIT. Regarding the regulatory response of post-exercise heart rate variability, Tabata HIIT demonstrated significant effects on the Sample Entropy (SampEn) parameter (g=0.32; 95% CI 0.03 to 0.61; p=0.03). However, no significant variations in affective states were observed after exercise. Conclusion: A single session of 4 minutes of Tabata HIIT is capable of improving mathematical performance in children without negatively influencing positive and negative affect in school-aged children. This low-cost, short-duration intervention may be a viable option for enhancing children's mathematical performance.