Pérdida de altura en el salto con contramovimiento e incremento en el lactato sanguíneo como indicadores de fatiga en jugadores juveniles de futbol sala

Abstract

Background: Decreased countermovement jump (CMJ) capacity and increased blood lactate (BL) concentration are normal at the end of futsal matches, so quantifying their magnitude is useful for monitoring exertion. Objective: To quantify the decrease in CMJ height and the increase in BL as indicators of fatigue in youth futsal players who live and compete at high altitude (2554 m above sea level). Method: A quantitative study with explanatory scope was conducted on a sample of 14 male players (16.5 ± 0.76 years; 62.3 ± 6.53 kg; 170.35 ± 6.49 cm) from the Cundinamarca U-17 team. These players were evaluated during a qualifying competition, which included three CMJ attempts and a finger-prick blood sample taken before and after each match. Using the statistical package R (version 4.5.1), a normality test (Shapiro-Wilk-Hollander) was performed, determining a non-parametric approach. This was followed by descriptive statistical analysis, correlation (Spearman test), and paired mean comparison (Wilcoxon test), with an alpha of 0.05. Results: The correlation between lactate sprint (LS) and countermovement jump (CMJ) was not statistically significant at any point (rho = 0.055, p = 0.654), while the difference between pre- and post-match measurements in both CMJ and LS was significant (W = 0.000; p < 0.05). Conclusion: both CMJ and LS can be used as indicators of fatigue in youth futsal players.