Efeito do treinamento pliométrico em diferentes densidades sobre o desempenho do salto Enjambée

Abstract

Among the body elements punctuated and required in the rhythmic gymnastics series, the jump manifests itself as an important element of difficulty. In Enjambée jump the gymnast needs to project one leg in front and one in the back, showing a minimum angle of 180º between them. Several types of exercises can be used to improve the performance of the jump, among them, the plyometric training, which is based on the stretching-shortening cycle for efficient performance, stands out. In addition, the organization of the density (i.e. exercise-rest relationship) used in training may also influence the performance of the jump. In this way, the present study aimed to determine the effect of physical training in different densities on the performance of the Enjambée jump. The study included 24 gymnasts aged 13 to 15 years (juvenile category). Two types of training were applied, both of which lasted for 12 weeks (2 adaptation and 10 training). The low density training (GEBD) was structured by short series, with more frequency of pauses, and the high density training (GEAD) by long series, with less frequency of pauses, which presents a greater propensity to trigger fatigue conditions. Using a battery of tests, the research verified the effects of training on the strength component (peak torque), neuromuscular parameters (level and pattern of muscle activation) and the relationship with jump performance (height and shape). The data were submitted to a standard descriptive analysis (mean and standard deviation) and normality and homogeneity by the Levene and Shapiro Wilk test. A series of analyzes of variance (ANOVA two way) was applied, in which the conditions group (intervention) and time (Pre-Post) were observed as factors, the latter being treated as a repeated measure. The Bonferroni test was applied to identify where the differences occurred. A Pearson chi-square (χ2) correlation test was applied to determine the effect of the peak torque variable on jump performance. Both groups had significant and similar increases in peak torque of the hip and knee flexor and extensor muscles (time effect; p <0.05). The analysis revealed no significant changes in the level of muscle activation, however a trend was detected in the post-intervention activation sequence. Significant and similar differences were observed at the height of the vertical jump between the Pre (GEAD, 28.40 ± 1.2cm and GEBD, 29.05 ± 1.4cm) and Post (GEAD, 32.10 ± 2.1cm and GEBD ; 32.65 ± 1.8 cm) for both groups. Regarding performance, there was no difference in the angle between the segments, however, both groups had significant and similar increases in the vertical displacement of the pos training iliac crest (time effect, p <0.05). The findings showed the effectiveness of the plyometric training, in both conditions in isometric strength gains, height of vertical jumps and Enjambeé, as well as the relationship between the strength of the flexors and extensors of the hip in the technical performance of the jump. Greater levels of activation were found in the RF and right and left BF muscles, in addition to the activation of the SG during the entire jump.