Strength-Power Performance of Visually Impaired Paralympic and Olympic Judo Athletes From the Brazilian National Team: A Comparative Study

Variability Analysis in Judo Para Athletes With Visual Impairments: Match-Outcome Performance in the Tokyo 2020 Paralympic Games With Evidence From the New Classification System

Match-related performance analysis in judo Para athletes with visual impairments is important to coaches and staff to identify technical-tactical profiles of their athletes and opponents but also to identify whether there are similar characteristics in each visual class. Thus, this study explores the match-related performance in judo Para athletes and verifies the relationship between performance using the old and new classification systems. The match-derived variables were analyzed using different statistical methods considering a total of 182 matches from the Tokyo 2020 Paralympic Games. The results indicated that performance was affected by sex and degree of impairment. The new classification system seems suitable for grouping Para judo athletes, as it differentiates performance between the two proposed classes (J1 and J2), since athletes from each group compete separately. Furthermore, different variability index measures were correlated with competitive performance, demonstrating a specific performance profile for each sport class in judo.

The Percentage of Total and Regional Fat Is Negatively Correlated with Performance in Judo

This study investigated the associations between total and regional body composition with performance in the special judo fitness test (SJFT), as well as strength and power tests (countermovement vertical jump-CMJ, squat jump-SJ, plyometric push-up-PPU, and force push-up-FPU). Twenty-three high-level judo athletes participated in this study. Initially, they underwent dual-energy X-ray absorptiometry, after which they performed the CMJ, SJ, PPU, and FPU tests. On another day, the SJFT was carried out. Correlations were tested using Pearson's test. The performance in the SJFT was correlated with the total and arm %fat mass (r = -0.759), torso fat mass (r = -0.802), torso %fat mass (r = -0.822) and in the lower limb regions with the leg fat mass (r = -0.803) and leg %fat (r = -0.745). In the strength and power tests, there were also negative correlations observed between regional fat and performance. There was a negative correlation between the percentage of total fat and performance in the SJFT (r = -0.824), SJ (r = -0.750), CMJ (r = -0.742), PPU (r = -0.609), and FPU (r = -0.736). Fat, both total fat and regional fat in the arms, torso, and legs, is strongly correlated with a poor performance in the SJFT and poor strength and power.

Effects of plyometric training on softer vs. Harder surfaces on jump-related performance in rugby sevens players

This study aimed to compare jump-related performance after plyometric training on harder vs. softer surfaces in rugby sevens players. Fourteen players were randomly assigned to the harder surface group (H-G, n = 7) and softer surface group (S-G, n = 7). Three times per week, in the morning, the players performed plyometric training on different surfaces and strength training. Before and after the 4-week intervention period, squat jump (SJ), countermovement jump (CMJ), and CMJ with arms (CMJA) tests were performed to measure vertical jump displacement (d), rate of force development (r), and power (p). The main results indicated a significant improvement in S-G for CMJd (∆% = +8.2%; p = 0.029; ES = 0.59) and for CMJAp (∆% = +8.7%; p = 0.035; ES = 0.44). These improvements were significant compared to H-G for CMJAd (F_1,12 = 8.50; p = 0.013; ηp2 = 0.41; ES = 0.83) and CMJAp (F_1,12 = 7.69; p = 0.017; ηp2 = 0.39; ES = 0.79). This study reveals that performance related to the counter movement jump with arms on softer surfaces after 4-week plyometric training improved vertical jump displacement and lower body power in rugby sevens players.

Differences in Strength, Speed, and Power Performance Between Visually Impaired Paralympic and Olympic Sprinters

PURPOSE

To compare the strength, speed, and power performance of elite sprinters with and without visual impairment.

METHODS

Twelve elite able-bodied sprinters and 15 Paralympic sprinters with visual impairment took part in this study. Sprinters from both groups performed the following tests: squat and countermovement jumps, maximum bar-power output in the half-squat and jump-squat exercises, and 60-m sprint. The differences between groups in all variables examined were analyzed using the independent t test.

RESULTS

Olympic sprinters revealed better performances in all tests when compared with Paralympic sprinters with visual impairment (effect sizes ranging from 1.29 to 9.04; P < .001). Differences of ∼32% and ∼20% were found for the half-squat and loaded and unloaded vertical jumps, respectively. Smaller differences (from ∼8% to ∼11%) were obtained in linear sprint performance.

CONCLUSIONS

Between-groups differences peaked at low-velocity exercises (eg, ∼32% in the half-squat) and decreased as movement velocity and specificity increased (eg, ∼8% at 60-m sprint). Thus, the greatest differences between Olympic and Paralympic sprinters seem to be related to their ability to apply force at low movement velocities. Coaches are encouraged to work on all sprinting phases and across the entire force-velocity spectrum, bearing in mind that improvements in strength capacity will possibly lead to increased sprint performance in Paralympic sprinters with visual impairment, especially in the acceleration phase of sprinting.

Kinetic and Kinematic Analyses of Countermovement Jump in a Small Sample of Individuals with Congenital Vision Loss

In the present study, we aimed to explore whether countermovement jumps (CMJs) performed by young adults with and without visual impairment (VI) differ. We compared three participants with congenital VI to 10 participants without congenital VI when both groups performed CMJs with maximum effort. Although the maximum jump height did not differ between groups, all three participants with VI showed such reduced maximum downward velocity of the center of body mass and a relative net negative vertical impulse that, on these measures, they fell beyond two standard deviations from the mean scores of participants without VI. The range of motion for the leg joints and countermovement depth did not differ between groups. Although findings from our small sample should be cross-validated and trainers should take care to protect athletes from falls, it appears from our preliminary data that a path to improved CMJ performance for athletes with VI is to increase their movement velocity in the countermovement phase of the jump.

The Optimum Power Load: A Simple and Powerful Tool for Testing and Training

PURPOSE

The optimal power load is defined as the load that maximizes power output in a given exercise. This load can be determined through the use of various instruments, under different testing protocols. Specifically, the "optimum power load" (OPL) is derived from the load-velocity relationship, using only bar force and bar velocity in the power computation. The OPL is easily assessed using a simple incremental testing protocol, based on relative percentages of body mass. To date, several studies have examined the associations between the OPL and different sport-specific measures, as well as its acute and chronic effects on athletic performance. The aim of this brief review is to present and summarize the current evidence regarding the OPL, highlighting the main lines of research on this topic and discussing the potential applications of this novel approach for testing and training.

CONCLUSIONS

The validity and simplicity of OPL-based schemes provide strong support for their use as an alternative to more traditional strength-power training strategies. The OPL method can be effectively used by coaches and sport scientists in different sports and populations, with different purposes and configurations.

Influence of Physical Fitness on Special Judo Fitness Test Performance: A Multiple Linear Regression Analysis

ABSTRACT

Lopes-Silva, JP, Panissa, VLG, Julio, UF, and Franchini, E. Influence of physical fitness on Special Judo Fitness Test performance: a multiple linear regression analysis. J Strength Cond Res 35(6): 1732-1738, 2021-The purpose of this study was to identify the physical fitness variables that best predict Special Judo Fitness Test (SJFT) performance. Thirty-five male experienced judo athletes took part in this study. All athletes performed 5 tests: upper- and lower-body cycle ergometer graded exercise tests; upper- and lower-body Wingate tests; and SJFT. The peak oxygen consumption (V̇o2peak), maximum heart rate (HRmax), maximum aerobic power, and the variables corresponding to onset blood lactate accumulation (OBLA) were determined during the graded exercise tests. For the Wingate tests, peak power (PP) and mean power were used. Furthermore, the total number of throws, heart rate (HR) immediately and 1 minute after, and SJFT index were calculated. Four separated forward multiple linear regressions (forward model) were used to identify the physical fitness variables that best explained the SJFT variables. Upper-body V̇o2peak (ml·min-1·kg-1) explained 27% of variance in the total number of throws, whereas an additional 7% was explained by upper-body PP. Upper-body HRmax explained 46% of the variance in the HR immediately after the SJFT, whereas lower-body HR at OBLA accounted for an additional 8%. Lower-body HRmax explained 21% of the variance in the HR 1 minute after the SJFT, whereas peak lactate ([La-]peak) after the lower-body graded exercise test accounted for an additional 12%. Upper-body V̇o2peak (ml·min-1·kg-1) alone accounted for 15% of the variance in the SJFT index. Based on these results, the data suggest that physical fitness variables, derived from upper- and lower-body aerobic and anaerobic tests, have a small ability to predict the SJFT variables.

Relationship Between Power Output and Speed-Related Performance in Brazilian Wheelchair Basketball Players

This study aimed to investigate the association between the optimum power load in the bench press (BP), shoulder press (SP), and prone bench pull (PBP) exercises and acceleration (ACC) and speed performances in 11 National Team wheelchair basketball (WB) players with similar levels of disability. All athletes were previously familiarized with the testing procedures that were performed on the same day during the competitive period of the season. First, athletes performed a wheelchair 20-m sprint assessment and, subsequently, a maximum power load test to determine the mean propulsive power (MPP) in the BP, SP, and PBP. A Pearson product-moment correlation was used to examine the relationships between sprint velocity (VEL), ACC, and the MPP in the three exercises. The significance level was set as p < .05. Large to very large significant associations were observed between VEL and ACC and the MPP in the BP, SP, and PBP exercises (r varying from .60 to .77; p < .05). The results reveal that WB players who produce more power in these three exercises are also able to accelerate faster and achieve higher speeds over short distances. Given the key importance of high and successive ACCs during wheelchair game-related maneuvers, it is recommended that coaches frequently assess the optimum power load in BP, SP, and PBP in WB players, even during their regular training sessions.

Neuromuscular and postural control in visually and nonvisually impaired judo athletes: case study

This study aimed to analyze neuromuscular and postural control in visually and nonvisually impaired judo athletes. Two judo athletes, one visually impaired and the other nonvisually impaired, participated in the study. The athletes presented similar demographic, anthropometric, and judo-technical characteristics. They performed maximal isometric handgrip strength (dominant and nondominant hand), vertical jumps (countermovement jump [CMJ] and squat jump [SJ]), and center of pressure assessment in three positions: neutral, anteroposterior, and judo combat base (Migi-shizentai). The main findings showed that the visually impaired athlete presented higher standing balance in the neutral and anteroposterior positions than non-visually impaired athlete (effect size [ES]>2.0). In the Migi-shizentai position, the disparity between both athletes was reduced, particularly in the displacement area (ES=0.52). The visually impaired athlete showed higher performance in the SJ but lesser performance in CMJ and handgrip strength tests than nonimpaired athlete (ES>2.0). We concluded that the postural stability was higher in the visually impaired athlete in the neutral and anteroposterior position, but similar to the nonvisually impaired athlete in Migi-shizentai position, possible due to the influence of judo practice. Moreover, the visually impaired athlete showed higher performance in the SJ than nonvisually impaired.

Performance Changes of Elite Paralympic Judo Athletes During a Paralympic Games Cycle: A Case Study with the Brazilian National Team

The aim of this study was to describe the variations in power performance of elite Paralympic judo athletes across three consecutive training cycles of preparation for the ParaPan American Games, the World Championship and the Paralympic Games. Eleven Paralympic judokas from the Brazilian National team participated in this study. They were repeatedly assessed using squat and countermovement jumps, mean propulsive power (MPP) in the jump-squat (JS), the bench press and prone bench pull at several moments of the preparation. Training supervision based on the optimum power zone (range of loads where power production is maximized) was provided in the final cycle, prior to the Paralympic Games. Magnitude-based inference was used to compare the repeated measurements of power performance. Lower and upper limb muscle power gradually increased throughout the cycles; however, the best results in all exercises were observed prior to the Paralympic Games, during which the team won four silver medals. As an illustration, prior to participation in the Paralympic Games the MPP in the JS was likely to very likely higher than prior to the World Championship (effect size [ES] = 0.77) and ParaPan American Games (ES = 0.53), and in January and March 2016 (ES = 0.98 and 0.92, respectively; months preceding the Paralympic Games). Power performance assessments can provide information about the evolution of Paralympic judokas, and training at the optimum power zone seems to constitute an effective method to improve lower and upper limb power in these athletes.

Authors' response to letter to the editor: "Bar velocities capable of optimising the muscle power in strength-power exercises" by Loturco, Pereira, Abad, Tabares, Moraes, Kobal, Kitamura & Nakamura (2017)

Our study in the Journal of Sports Sciences was originally designed to test whether the bar-velocity is a precise indicator of the power training intensity (i.e., optimum loads) in different exercises commonly included in athletes' training programs. Furthermore, we presented secondary findings, related to the actual results obtained in our assessments. As a cross-sectional study with clear objectives, we focused on discussing issues and applications pertaining to neuromuscular training interventions, such as: (1) describing the advantages of using bar-velocities to control the power training intensity, (2) defining a range of loads capable of maximizing the power production in certain ballistic and traditional exercises, and (3) revealing the differences between these exercises and the respective implications for training. Fundamentally, we did not produce a mechanistic investigation and were very accurate and consistent in reporting our data, collected under rigorous and well-established experimental conditions. Here we provide our point-by-point comments to the concerns raised in the "Letter to the Editor", along with some theoretical explanations about the secondary findings reported by the authors of the Letter. To better understand the nature and purposes of our experiment, we also present a series of practical examples and review previous investigations involving the "bar-power" approach.