Purpose: To analyze the effects of different inertial loads on power production and power maintenance, as well as the number of sessions required for proper familiarization during the flywheel quarter-squat. Methods: Twenty-four high-level handball players attended 4 testing sessions consisting of 4 sets of 10 repetitions using 4 different inertial loads (0.025, 0.050, 0.075, and 0.100 kg·m2). In addition, a 5th set of 15 repetitions was performed. Both concentric and eccentric peak power and the eccentric:concentric ratio were recorded. Results: The results showed the need to perform 3 sessions for a proper familiarization (ie, outcomes stabilization). The inertial load of 0.025 kg·m2 led to greater concentric peak power compared with the other inertial loads (from likely to most likely greater values). Both 0.025 and 0.050 kg·m2 inertial loads entailed greater eccentric peak power compared with 0.075 and 0.100 kg·m2 (most likely greater). Conversely, the 0.025-kg·m2 inertial load showed a lower eccentric:concentric ratio, presenting negative effects (most likely lower values) compared with the inertial loads of 0.050, 0.075, and 0.100 kg·m2. Participants were able to perform 5–12 repetitions per set without significant peak power output decrements. Conclusions: This study highlights the importance of performing at least 3 sessions to obtain a stable measure during flywheel squat exercise. Lower inertial loads (0.025 kg·m2) are the better option for eliciting high concentric peak power output values. In contrast, medium to high inertial loads are more appropriate to achieve greater eccentric overload values.
Rafael Sabido, Jose Luis Hernández-Davó and Gabriel T. Pereyra-Gerber
Raúl Reina, Aitor Iturricastillo, Rafael Sabido, Maria Campayo-Piernas and Javier Yanci
Purpose: To evaluate the reliability and validity of vertical and horizontal jump tests in football players with cerebral palsy (FPCP) and to analyze the jump performance differences between current International Federation for Cerebral Palsy Football functional classes (ie, FT5–FT8). Methods: A total of 132 international parafootballers (25.8 [6.7] y; 70.0 [9.1] kg; 175.7 [7.3] cm; 22.8 [2.8] kg·m−2; and 10.7 [7.5] y training experience) participated in the study. The participants were classified according to the International Federation for Cerebral Palsy Football classification rules, and a group of 39 players without cerebral palsy was included in the study as a control group. Football players’ vertical and horizontal jump performance was assessed. Results: All the tests showed good to excellent relative intrasession reliability scores, both in FPCP and in the control group (intraclass correlation = .78–.97, SEM < 10.5%). Significant between-groups differences (P < .001) were obtained in the countermovement jump, standing broad jump, 4 bounds for distance, and triple hop for distance dominant leg and nondominant leg. The control group performed higher/farther jumps with regard to all the FPCP classes, obtaining significant differences and moderate to large effect sizes (ESs) (.85 < ES < 5.54, P < .01). Players in FT8 class (less severe impairments) had significantly higher scores in all the jump tests than players in the lower classes (ES = moderate to large, P < .01). Conclusions: The vertical and horizontal jump tests performed in this study could be applied to the classification procedures and protocols for FPCP.