Excerpt:The power position is an integral position for a variety of power lifting movements. Athletes can develop their power position via an integrated approach involving sound exercise selection and purposeful instruction leading to enhanced strength and technique...

O desenvolvimento da potência muscular e das habilidades motoras como salto vertical, velocidade de corrida e agilidade é fundamental para um bom desempenho nas modalidades esportivas coletivas, dentre elas o handebol. Os exercícios do levantamento de peso olímpico (LPO), dentre eles o hang power clean (HPC), têm sido comumente utilizados para esta finalidade; porém, pouco se sabe a respeito do efeito de diferentes intensidades de treinamento com o HPC sobre o desempenho motor de atletas. Desta forma, o objetivo do estudo foi investigar o efeito de dois protocolos de treinamento com 50% e 90% 1RM no exercício HPC nos ganhos de potência muscular dos membros inferiores, na altura do salto vertical, na velocidade de corrida, na mudança de direção e na força dinâmica máxima de jogadoras de handebol. Dezesseis atletas das categorias júnior e adulto foram divididas em dois grupos (LPO50 e LPO90; 50% e 90% 1RM, respectivamente) e submetidas a 15 sessões de treinamento durante sete semanas. Testes de potência muscular dos membros inferiores, altura do salto vertical sem e com contra-movimento (SJ e CMJ, respectivamente), velocidade de corrida, mudança de direção e força dinâmica máxima (1RM) nos exercícios meio-agachamento e HPC foram realizados pré- e pós-treinamento. Após o período de treinamento foi observado aumento significante da potência de membros inferiores no CMJ com 40% da massa corporal (MC) somente para o grupo LPO90, enquanto nenhuma alteração significante ocorreu no CMJ 60% e 80% MC para ambos os grupos. Não foram observadas alterações significantes na altura dos saltos verticais (SJ, CMJ e CMJ com diferentes sobrecargas externas) para os dois grupos; porém, a velocidade de corrida nas distâncias 0-5, 0-20 e 0-30m aumentou de forma significante e semelhante entre LPO50 e LPO90. Houve diminuição significante no desempenho da mudança de direção no teste T-40 para ambos os grupos. A 1RM no exercício HPC aumentou para os dois grupos enquanto nenhuma alteração significante foi observada para o exercício meio-agachamento. Assim, após 15 sessões de treinamento com HPC em diferentes intensidades (50% vs. 90% 1RM), pode-se afirmar que a utilização de menores intensidades promoveu adaptações positivas muito similares à utilização de maiores intensidades na velocidade de corrida e na força dinâmica máxima no exercício HPC, em jogadoras de handebol / The development of muscle power and motor skills such as vertical jump, running speed and agility is fundamental for a good performance in several team sports, among them handball. Olympic weightlifting (OWL) exercises such as the hang power clean (HPC) have been commonly used for this purpose; however, little is known about the effect of different training intensities with HPC on athletes\' motor performance. Thus, the objective of the study was to investigate the effect of two training protocols with 50% and 90% 1RM of the HPC exercise on lower limbs muscle power, vertical jump height, running speed, agility, and maximum dynamic strength of female handball players. Sixteen junior and adult athletes were divided into two groups (OWL50 and OWL90, 50% and 90% 1RM, respectively) and underwent 15 training sessions for seven weeks. Test for lower limbs muscle power, squat jump and countermovement jump height (SJ and CMJ, respectively), running velocity, agility, and maximal dynamic strength (1RM) in half-squat and HPC exercises were performed pre- and post-training. After the training period, a significant increase in lower limbs power in the CMJ was observed with 40% of body mass (BM) only for the OWL90 group, while no significant alteration occurred in the CMJ 60% and 80% BM for both groups. No significant changes were observed in vertical jumps height (SJ, CMJ and CMJ with different external loads) for both groups; however, running speed at 0-5, 0-20 and 0-30m increased significantly and similarly between OWL50 and OWL90. There was a significant decrease in agility performance for both groups. The 1RM in the HPC exercise increased for both groups while no significant change was observed for the half-squat exercise. Thus, after 15 training sessions with HPC at different intensities (50% vs. 90% 1RM), it can be stated that the use of lower intensities promoted positive adaptations in running speed and maximum dynamic strength in the HPC exercise similar to the use of higher intensities, in handball players

O desempenho geral de um atleta está diretamente relacionado com o desenvolvimento da potência muscular, sendo esta a maior característica dos praticantes do Levantamento de peso olímpico (LPO), daí a sua utilização em diferentes planejamentos esportivos em procura do melhoramento do desempenho e potência muscular. Os movimentos do LPO recrutam os maiores grupos musculares e requerem intensos esforços físicos realizados com ênfase na velocidade e técnica. Velocidade, coordenação, níveis de coativação muscular são características dos movimentos próprios do Levantamento de Peso Olímpico e que são adquiridos e aperfeiçoados no tempo. O Power Snatch (PS) é um movimento derivado do Arranco, considerado como um dos movimentos mais difíceis de executar pela sua complexidade técnica. O PS é utilizado em diferentes modalidades esportivas em procura de elevar o desempenho atlético. Estudos prévios registraram dados cinemáticos e/ou medições eletromiográficas, mas sempre foram com atletas de alto rendimento. O presente estudo investigou os padrões cinemáticos e atividades musculares que representariam a execução técnica do PS e comportada por uma trajetória ótima observada desde o plano sagital do executante. Dezenove voluntários participaram do estudo, 11 sujeitos foram treinados (GT) durante 6 semanas e a cada duas semanas as variáveis cinemáticas e de atividade muscular foram registradas. 8 especialistas (GE) em levantamento participaram para registrar suas execuções técnicas. O PS foi dividido em 6 fases, representadas por 48 variáveis que comportam a análise cinemática por cada sujeito divididos em 3 sessões. 16 variáveis representaram dados da trajetória do GE. 8 músculos, correspondentes ao lado dominante de cada sujeitos foram registrados. Os dados cinemáticos e de atividade muscular foram analisados e comparados. Foram identificados parâmetros que comportam a trajetória óptima da barra e das atividades musculares nas diferentes fases da execução técnica do PS. O GT mostrou mudanças na sua execução, sendo que algumas delas se aproximaram aos do GE. Os coeficientes de ativação muscular foram maiores no GT que no GE. Os resultados do presente estudo levantam a questão da possibilidade de que a trajetória ótima no PS existe, mas varia entre os diferentes executantes / The performance of an athlete is directly related to the development of muscular power, this being the main characteristic of the Olympic Weightlifting (OW) practitioners. Hence their use in different training plans in order to improve performance and muscular power. The OW movements recruit the largest muscle groups and require intense physical effort performed with emphasis on speed and technique. Speed, coordination, levels of muscular coactivation are characteristic of the movements of the Olympic Weightlifting themselves and are acquired and improved over time. Power Snatch (PS) is a movement derived from the Snatch, considered as one of the most difficult movements to perform due to its technical complexity. The PS is used in different sports modalities in order to increase athletic performance. Previous studies have recorded kinematic data and/or electromyographic measurements, but these studies were limited to elite athletes. The present study investigated the kinematic patterns and muscular activities that represent the technical execution of the PS, referred by an optimal trajectory observed from the sagittal plane of the performer. Nineteen volunteers participated in the study, 11 subjects were trained (GT) for 6 weeks and every two weeks the kinematic and muscle activity variables were recorded. 8 specialists in ow training (GE) participated to register their technical executions. The PS was divided into 6 phases, represented by 48 variables that involve the kinematic analysis for each subject divided into 3 sessions. 16 variables represented GE trajectory data. 8 muscles, corresponding to the dominant side of each subject were recorded. Kinematic and muscle activity data were analyzed and compared. Parameters were identified that include the optimal trajectory of the bar and muscular activities in the different phases of the PS technical execution. The GT showed changes in its execution, with some of them approaching those of GE. The muscle activation coefficients were higher in the GT than in the EG. The results of the present study raise the question of the possibility that the optimal trajectory in PS exists, but varies among the different performers

The purpose of this study was to determine if there was a significant relationship between the academic achievement as measured by ACT English, math, and composite scores of students who took 6 or more credits of weightlifting, 6 or more credits of performing arts, or no elective focus in an East Tennessee high school serving grades 9-12 from the graduating classes of 2010 through 2014. The independent variables were the elective focus groups students took during high school and race and ethnicity. The dependent variables were ACT English, math, and composite scores. A series of one-way analyses of variances (ANOVAs) were performed to examine the differences in the mean ACT scores for the students taking 6 or more credits of weightlifting, 6 or more credits of performing arts, or no elective focus. Significant differences were found between the ACT English, math, and composite scores for students taking 6 or more credits of performing arts and no elective focus and students taking 6 or more credits or weightlifting and no elective focus. There was not a significant difference between the students taking 6 or more credits of weightlifting and 6 or more credits of performing arts. Based upon the findings of the study students taking 6 or more credits of performing arts had significantly higher ACT English, math, and composite scores than students with a weightlifting focus or no elective focus. Two-way analyses of variance were also performed to study the relationships between the academic performance as measured by ACT English, math, and composite scores of White and non-White students. White students performed significantly higher than non-White students on ACT English, math, and composite scores. There was no significant interaction between race and ethnicity and elective focus groups; however, there were significant main effects in race and ethnicity and elective focus groups. There were significant differences in the ACT math and composite scores between the weightlifting and performing arts groups as well as performing arts and no elective focus area. There was not a significant difference between the weightlifting and no elective focus. There were significant differences between all pairs of groups for ACT English. The performing arts focus group scored significantly higher than the other groups on all 3 ACT subtests.

The purpose of this dissertation was to determine the effects of several loads and multiple inter-repetition rest (IRR) intervals on peak power, peak velocity, and peak force in multiple sets of hang power cleans. Additionally, this dissertation investigates the load at which power and barbell velocity are maximized in a hang power clean, which is an area of the literature that requires greater clarity. From a practical perspective it is exceedingly difficult to make training recommendations to maximize power development or prescribe load and IRR intervals in cluster loading based on the current literature. The primary findings of this dissertation are 1) 70% 1RM maximizes power and velocity as compared to 80% 1RM in multiple sets of the hang power clean, 2) 45 seconds IRR improved peak velocity and peak power relative to a traditional set configuration, and 3) peak power output at 80% 1RM with 45 seconds IRR is equivalent to power output at 70% 1RM using a traditional set configuration. To the authors’ knowledge this is only the second study to examine the effect of IRR on multiple sets of power cleans in trained participants, and the insights from this dissertation help to build a foundation for future investigations in cluster loading with weightlifting movements. The findings from this dissertation provide further evidence for the efficacy of cluster loading as a training tool to develop power in trained individuals.

Various body positions have been used in the scientific literature when performing the isometric midthigh pull resulting in divergent results. We evaluated force production in the isometric midthigh pull in bent (125° knee and 125° hip angles) and upright (125° knee, 145° hip angle) positions in subjects with (>6 months) and without (<6 months) substantial experience using weightlifting derivatives. A mixed-design ANOVA was used to evaluate the effect of pull position and weightlifting experience on peak force, force at 50, 90, 200, and 250 ms. There were statistically significant main effects for weightlifting experience and pull position for all variables tested, and statistically significant interaction effects for peak force, allometrically scaled peak force, force at 200 ms, and force at 250 ms. Calculated effect sizes were small to large for all variables in subjects with weightlifting experience, and were small to moderate between positions for all variables in subjects without weightlifting experience. A central finding of the study is that the upright body position (125° knee and 145° hip) should be used given that forces generated are highest in that position. Actual joint angles during maximum effort pulling should be measured to ensure body position is close to the position intended.

Peak barbell velocity is an important determinant of weightlifting performance 2 . However, direct comparisons of this measure between elite men and women weightlifters is limited 7,8 . Therefore, the present study sought to establish a reference of the current status and trajectory of sexbased peak barbell velocity differences among elite weightlifters. This study examined performances of men and women in the 69 kg weight class in order to obviate the influence of body mass on performance. The purpose of this investigation was to help practitioners identify training needs of elite men and women weightlifters to improve weightlifting performance based upon between-group differences in peak barbell velocity.

This study analyzed the top 3 successful snatch attempts by individual lifters in each weight class at a U.S. National Championship weightlifting meet. Two-dimensional (2-D) body position and characteristics of the lifts were compared via 2D video analysis in groups of lifters who displaced forward, showed no displacement, or displaced backward to receive the bar. No significant group differences (p > 0.05) were noted for body mass, bar mass, or hip angle. The rearward displacement group had a significantly greater horizontal distance between the shoulder and heel at the end of the pull (determined as the point where the bar ceases to accelerate vertically). Hip angles for the no displacement group had a small-to-moderate effect size (0.50) in comparison to the forward displacement group, but they only showed a small effect size (0.17) when compared with the rearward displacement group. The forward displacement group showed a small-to-moderate effect size compared with both the no displacement group (0.51) and the rearward displacement group (0.55) concerning the horizontal distance from the shoulder to the heel. These data seem to suggest that rearward displacement in the drop-under phase in the snatch is not detrimental to performance and actually seems to be a preferred technique in U.S. national level lifters. In addition to evidence that rearward displacement is exhibited in elite lifters and is coached globally, it seems this is the preferred technique in international competitions. This technique may be considered a viable variation of the snatch by coaches and athletes of all levels.

The principal aim of the present thesis was to prospectively follow (clinical status and ultrasound + Doppler findings) the patellar tendons in the young elite volleyball players at the Swedish National Centre for high school volleyball in Falköping. In an Olympic weightlifter with chronic painful jumper´s knee, the effects of treatment with sclerosing injections followed by early instituted very heavy weightlifting training, was also evaluated. First, in a prevalence study, we demonstrated that the clinical diagnosis patellar tendinopathy-jumper’s knee, together with structural tendon changes and vascularisation in the painful area of the tendon, was demonstrated in 12/114 tendons in Swedish junior elite volleyball players, but not in any tendons of individually matched (age, height and weight) not regularly sports active controls. Structural tendon changes alone was demonstrated among the volleyball players but also among the controls. In a 7 months prospective study of a total of 120 tendons, we demonstrated that the clinical diagnosis patellar tendinopathy-jumper’s knee was associated with neovessels/vascularity in the area with structural tendon changes in 17/19 tendons. Seventy tendons that at start were clinically normal, and had normal ultrasound + Doppler findings, remained clinically normal after 7 months with intensive training and playing volleyball. In a 3-year prospective study it was demonstrated that normal clinical tests and normal ultrasound + Doppler findings at school start, indicated a low risk (8%) for these players to sustain patellar tendinopathy-jumper’s knee during the 3 school years with intensive training and playing. In a case study, involving an Olympic elite weightlifter with chronic painful patellar tendinopathy-jumper’s knee, successful treatment with ultrasound and Doppler-guided injection of the sclerosing agent polidocanol, allowed for pain-free very heavy weight training two weeks after treatment. Further heavy weightlifting training on a daily basis, preparing for European Championships, was done without causing tendon rupture and/or pain. Key words: Jumper’s knee, Patellar tendinopathy, Chronic pain, Ultrasonography, Doppler, Neovascularisation, Volleyball, Weightlifting

INTRODUCTION: Monitoring an athlete’s psychological, physiological, and performance level is important when preparing for a major competition. No study to date has tracked a high-level weightlifter peaking for a major competition all the way up to the day of competition. Assessing performance at a competition is vital to ascertain if the athlete has reached a peaked and if peak performance will actually be expressed during the competition. PURPOSE: Therefore, the purpose of this study was to determine when peak jumping performance was achieved and whether psychological or physiological variables explained any jump performance changes in a high-level female weightlifter preparing for a national competition. We hypothesized that jumping performance would peak on competition day corresponding with improved recovery and stress states and preserved muscle cross-sectional area (CSA) relative to baseline values. METHODS: A USA national-level female weightlifter (23.5y; 54.0±0.6kg; 155.4cm) participated in this investigation. Laboratory testing was carried out over a 7-month period as part of an ongoing long-term athlete monitoring program. At 11-weeks out, testing was administered twice a week for each week leading up to competition, at the competition, and returning from the competition. Each testing session evaluated body mass, recovery-stress inventories using the short recovery and stress scale (SRSS), and vastus lateralis CSA via ultrasonography followed by a standardized warm-up preceding unloaded squat jumps (SJ) performed on dual force plates sampling at 1kHz. Hopkin’s effects size (ES) classifications for each data point was used to determine the potential magnitude of change observed for each test relative to baseline values. The smallest worthwhile change was used to determine a meaningful change relative to baseline values. This typical error and smallest worthwhile change were used to quantify the probability (i.e., precision) of performance change that took place. Values greater or less than baseline values with precision >95% signified a very likely change for each testing session relative to the competition. RESULTS: Weightlifting performance goals were met for the national championship (snatch=67kg, clean and jerk=92kg, total=159kg). Jumping performance (precision=99%,ES=2.7) was almost certainly peaked on competition day with increased recovery (ES=0.7) and decreased stress scores (ES=0.5). However, the athlete possibly exhibited a small decrease in muscle CSA (precision=64.8%;ES=0.4) the week of competition that corresponded with very large changes in body mass (precision=99%;ES=2.8). CONCLUSIONS: The training program was effective in ensuring the athlete was peaked the day of competition based on jumping performance and recovery-stress scores despite small decreases in CSA. Thus, weightlifting coaches and sport scientists working with high-level athletes should monitor jumping performance and recovery-stress state to ensure athletes peak at an appropriate time. PRACTICAL APPLICATIONS: SRSS and SJ testing can be used as monitoring tools for high-level weightlifters preparing for important competitions.