This study examined and compared static, countermovement, and rebound-type drop jumps from the upper and lower extremities among USA Junior National Team male gymnasts. Twenty-one gymnasts performed two repetitions each of upper (UE) and lower extremity (LE) static (SJ), countermovement (CMJ), and drop (DJ) jumps on a force platform. Average measures of maximum jump height (MXHT), peak force (PF), rate of force development (RFD), and peak power (PP) were calculated for analysis. In addition, sample-specific allometric scaling was used to scale PF and PP. Four 2x3 repeated measures ANOVAs were calculated for analyses. Statistically significant main effects were observed for UE vs LE for MXHT, PF, RFD, and PP (all p < 0.001). Statistically significant main effects for jump-type were also observed: MXHT, PF, RFD, and PP (all p < 0.001). Finally, statistically significant extremities x jump-type interaction effects were obtained for MXHT, PF, RFD, and PP (all p < 0.001). These gymnasts showed better performances in CJs relative to SJs, but performances were unexpectedly poorer in the DJs. Despite using rebound-type jumps in tumbling and vaulting with UE and LE, the DJs did not appear to capture the athletes’ stretch-shortening cycle skill or may reflect poor stretch-shortening cycle skill.

Background: Jump height, utilization of the stretch-shortening cycle (SSC) and knee stability is key qualifications and important factors for athletic performance. This is usually practiced with the help of plyometric training. However, plyometric training is considered as an exercise with high-impact that adds stress on the body. Trampoline training is an activity with a growing number of adolescent’s performers, and with the ability to train the same qualities that plyometric training. However, few studies have investigated trampoline trainings effect on jump height, utilization of the SSC and the knee stability in comparison to ordinary plyometric exercises. Aim: The aim of the study was to investigate whether the jump height in a countermovement jump (CMJ) and a squat jump (SJ), the use of SSC and knee stability at landing is different in adolescents who are training using a trampoline and adolescents training using plyometric exercises. Methods: Thirty (n=30) participants, 19 handball players and 11 trampoline practitioners, aged 14-18 years, completed this cross-sectional study. This study involved three tests, a CMJ and a SJ for measuring the jump height and SSCand a double leg drop jump test for measuring the knee stability. Results: The result showed a significant difference in relative jump value between the groups, were the handball group showed a higher value in the CMJ and the SJ compared to the trampoline group. In the utilization of the SSC there were no significant difference between the groups. The result showed that there was a significant difference between the groups knee stability, were the handball group showed a greater knee degrees of varus compared to the trampoline group. Conclusion: Findings from this study suggests that adolescents might benefit from performing plyometric training to achieve a greater jump height and trampoline training to achieve a greater knee stability. Both activities had the same effect on the utilization of theSSC. More studies are needed, including a more homogenous group with larger sample sizes, to support the present results and investigate whether the results are reliable.

Plyometric training has always been a topic of interest in terms of sport perfor-mance enhancement and development. The most relevant and up-to-date data has been reviewed to try to answer the question “what kind of plyometric training to use” to improve ones’ performance. The present study demonstrates the use of re-active strength index (RSI) and force-velocity profiling. In the text there is also a presentations of common jumping tests that help practitioners to establish a profile of an athlete. Main findings of this study are: general strength should be developed alongside reactive strength qualities, plyometric training optimized and guided by RSI is highly effective in improving reactive strength ability, demands of a sport determine the manner in which plyometric exercises should be performed, RSI can be used as a representation of neuromuscular fatigue, force-velocity (F-v) approach may help improve the training practice for performance in explosive push-off ac-tions like jumping, through a more efficient monitoring and understanding of the individual determinants of athletic performance, showing the sensitivity of the F-v profile to specific training programs can result in either maximal force or velocity capabilities improvements (determination of F-v imbalances or FVimb) – which is termed “optimized training” and it has been found that an optimized and individu-alized training program specifically addressing the FVimb is more efficient for im-proving jumping performance than traditional resistance training.

Suchomel, TJ, Bailey, CA, Sole, CJ, Grazer, JL, and Beckham, GK. Using reactive strength index-modified as an explosive performance measurement tool in Division I athletes. J Strength Cond Res 29(4): 899-904, 2015 - The purposes of this study included examining the reliability of reactive strength index-modified (RSImod), the relationships between RSImod and force-time variables, and the differences in RSImod between male and female collegiate athletes. One hundred six Division I collegiate athletes performed unloaded and loaded countermovement jumps (CMJs). Intraclass correlation coefficients and typical error expressed as a coefficient of variation were used to establish the relative and absolute reliability of RSImod, respectively. Pearson zero-order product-moment correlation coefficients were used to examine the relationships between RSImod and rate of force development, peak force (PF), and peak power (PP) during unloaded and loaded jumping conditions. Finally, independent samples t-tests were used to examine the sex differences in RSImod between male and female athletes. Intraclass correlation coefficient values for RSImod ranged from 0.96 to 0.98, and typical error values ranged from 7.5 to 9.3% during all jumping conditions. Statistically significant correlations existed between RSImod and all force-time variables examined for male and female athletes during both jumping conditions (p ≤ 0.05). Statistically significant differences in RSImod existed between male and female athletes during both unloaded and loaded CMJs (p < 0.001). Reactive strength index-modified seems to be a reliable performance measurement in male and female athletes. Reactive strength index-modified may be described and used as a measure of explosiveness. Stronger relationships between RSImod, PF, and PP existed in female athletes as compared with that in male athletes; however, further evidence investigating these relationships is needed before conclusive statements can be made. Male athletes produced greater RSImod values as compared with that produced by female athletes.

The purpose of this study was to examine the differences in reactive strength index-modified (RSImod), jump height (JH), and time to takeoff (TTT) between 6 U.S. collegiate sport teams. One hundred six male and female Division I collegiate athletes performed unloaded (<1 kg) and loaded (20 kg) countermovement jumps as part of an ongoing athlete monitoring program. Reactive strength index-modified, JH, and TTT values for each team were compared using 1-way analysis of variance. Statistically significant differences in RSImod (p < 0.001), JH (p < 0.001), and TTT (p 0.003) existed between teams during the unloaded jumping condition. Similarly, statistically significant differences in RSImod (p < 0.001), JH (p < 0.001), and TTT (p 0.028) existed between teams during the loaded jumping condition. Men's soccer and baseball produced the greatest RSImod values during both the unloaded and loaded jumping conditions followed by women's volleyball, men's tennis, women's soccer, and women's tennis. The greatest JH during unloaded and loaded jumping conditions was produced by men's baseball followed by men's soccer, women's volleyball, men's tennis, women's soccer, and women's tennis. Men's soccer produced shorter TTT compared with men's baseball (12.7%) and women's soccer (13.3%) during the unloaded and loaded jumping conditions, respectively. Collegiate sport teams exhibit varying reactive strength characteristics during unloaded and loaded jumping conditions. Understanding the differences in RSImod between sports may help direct the creation of training and monitoring programs more effectively for various sports.

Orientador: Gil Lucio Almeida / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-06T21:23:30Z (GMT). No. of bitstreams: 1 Santos_MarcusViniciusRezendedos_M.pdf: 2514721 bytes, checksum: a7b1ab66caadf0d4fb9a3367038033d5 (MD5) Previous issue date: 2005 / Resumo: Neste trabalho, foram investigados efeitos de condições especiais como o envelhecimento e a Doença de Parkinson no controle de movimentos reversos do cotovelo, realizados com um atraso variável entre a ida (Ml) e a volta (M2) do mesmo. Outro objetivo foi verificar se o ciclo de alongamento-encurtamento (CAE) age como potencializador da contração muscular nessa população. Foram recrutados 12 voluntários, sendo seis sujeitos saudáveis (três homens e três mulheres) com idades entre 51 e 71 anos (Média = 62.33 e DP = 8.95) e seis portadores da doença de Parkinson (três homens e três mulheres) com idades entre 59 e 77 anos (Média = 68.66 e DP = 7.47). Eles realizaram movimentos uni-articulares rápidos de reversão com o cotovelo, que se movia em direção à um alvo (Ml) e depois retomava à posição inicial (M2). Esses movimentos foram realizados em três diferentes distâncias (20°, 40° e 60°) e entre os dois componentes (Ml e M2) foi realizado um atraso variável (Os, 0.2s, 0.5s e ls). O deslocamento angular do cotovelo foi registrado por um sistema óptico de análise do movimento (OPTOTRAK@ 3020) e a atividade elétrica dos músculos braquiorradial (BRR) e cabeça lateral do tríceps braquial (TR) foi registrada através de um eletromiógrafo EMG DelSYS (modelo DE2.2L) com eletrodos de superficie. O envelhecimento saudável não influenciou os padrões EMG utilizados por esses indivíduos para ativar os músculos agonista e antagonista na realização de movimentos uni-articulares com reversão com diferentes atrasos. A velocidade dos movimentos executados por esses indivíduos foi mais baixa devido ao uso de um padrão semelhante aos sujeitos jovens, porém com uma menor quantidade de ativação. Os parkinsonianos moveram mais lentamente que os idosos saudáveis e indivíduos saudáveis devido a algumas alterações na modulação da atividade EMG. Apesar de apresentarem a manutenção do padrão trifásico, a atividade elétrica dos músculos ocorreu na forma de vários bursts altemantes durante toda a realização da tarefa, o que provocou uma redução na quantidade de ativida elétrica dos músculos. Os parkinsonianos não reduziram a magnitude do segundo burst agoninos movimentos sem atraso, o que trouxe uma dificuldade maior para reverter os moviment< Por fim, notou-se que os indivíduos portadores da doença de Parkinson relaxavam menos a SI musculatura e iniciavam o retomo à posição inicial necessitando de uma atividade maior do 1 para gerar uma velocidade igual à dos indivíduos saudáveis, o que não aconteceu. ( movimentos que reverteram sem atraso apresentaram um valor maior da velocidade movimento de retomo à posição inicial, mesmo nos portadores da doença de Parkinso confirmando a ação potencializadora do ciclo de alongamento-encurtamento (CAE) sobre músculo tríceps. Isso suporta a influência, tanto dos reflexos (gerados pelo estiramento muscula quanto da energia potencial armazenada pelo músculo e tendão, que têm suas origens na fa: excêntrica do CAE e são liberados no movimento de volta (fase concêntrica). Palavras-chave: Movimentos reversos, doença de Parkinson, ciclo de alongamento encurtamento, eletromiografia e cinemática / Abstract: Within this study were investigated the effects of special conditions like aging and the Parkinson's disease on the control ofreversal movements ofthe elbow joint performed with a variable delay between the two components (Ml and M2) ofreversal. Another aim was to verify if the stretch-shortening cycle exerts his potentiating effects on muscular contraction in this population. To perform these observations, 12 volunteers were recruited. Six of them (3 males and 3 females) were normal at their neurological assessment and were between 51 and 71 years of age (Mean = 62.33 e S.D.= 8.95), and the other six (3 males and 3 females) had been diagnosised with Parkinson disease and were between 59 and 77 years old (Mean = 68.66 e S.D. = 7.47). They executed fast single-joint movements with a reversal, moving towards a target (Ml) and getting back to the initial position (M2). These movements were accomplished in three different distances (20°, 40° and 60°) and between the two components ofreversal (Ml e M2) there were variable delays (Os, 0.2s, 0.5s eIs). The elbow angle was recorded using a optoelectric system of motion analysis (OPTOTRAK@ 3020) and the electrical activity of braquioradialis (BRR) and lateral head of triceps brachi (TR) muscles were recorded by a electromyograph EMG DelSYS (model DE2.2L) with surface electrodes placed over the muscles bellies. The aging did not affect the EMG patterns used by these persons in activating the agonist and antagonist muscles to accomplish single-joint movements with a delay between the movements toward the target and the return to the initial position. The velocity of movements executed by the elder1y volunteers was lower due to the fact that the same strategy applied to young hea1thy persons was used, however with less EMG activity. The volunteers with Parkinson's disease moved slower than the heaIthy elderly and young subjects due to aIterations in the modulation of EMG activity. Altough they kept the triphasic pattern, the EMG showed multiple bursts that aItemated during the task accomplishmen~ which decreased the amount of ellectricaI activity. Besides, they did not reduce the magnitude of second agonist burst in the reversaI movements without delay, what made the reversion harder. FinaIly, it was noticed that the parkinsonians showed less relaxation of his muscles during the intervaI between TI-T4, and started the return movement needing more TR activity to produce the same velocity, when compared to heaIthy persons, which was not the case. Those movements that reverted with no delay showed higher values concerning the second peak ofvelocity, even within the volunteers with Parkinson disease, sustaining the potentianting action of SSC over the triceps muscle. This effect comes from the influence of reflexes (generated by the muscle stretching), as well as the storage of elastic energy in the muscle and tendon in the eccentric phase of SSC, which are released at the movement of returning (concentric phase) / Mestrado / Fisiologia / Mestre em Biologia Funcional e Molecular

Introduktion: Plyometrisk träning är en högintensiv träningsform för att förbättra atletisk prestation som exempelvis explosiv styrka och effektutveckling. Plyometrisk träning i vatten är däremot mindre undersökt men tidigare forskning tyder på att det verkar ha liknande effekter som landbaserad plyometrisk träning. Syfte: Litteraturundersökningens syfte är att undersöka om det finns en effekt av plyometrisk träning i vatten på hopphöjd, muskelstyrka och muskelömhet. Ytterligare ett syfte är att jämföra effekterna mellan plyometrisk träning i vatten med landbaserad plyometrisk träning på hopphöjd, muskelstyrka och muskelömhet. Metod: En systematisk sökning genomfördes i de vetenskapliga databaserna Pubmed och Web of Science. Utöver detta genomsöktes samtliga referenser på de artiklar som uppfyllde inklusionskriterierna. Resultat: Litteraturundersökningen visade att plyometrisk träning i vatten verkar ha en effekt på hopphöjd. Muskelstyrka och muskelömhet visade inget tydligt utfall. Plyometrisk träning i vatten verkar ha samma effekt på hopphöjd och muskelstyrka som landbaserad plyometrisk träning. Vattenbaserad plyometrisk träning verkar ge mindre muskelömhet jämfört med landbaserad plyometrisk träning. Konklusion: Det behövs mer forskning i området för att fastställa vilka faktorer som gör att vattenbaserad plyometrisk träning är lika effektiv som landbaserad träning för att förbättra hopphöjd. Det behövs mer forskning på plyometrisk träning i vatten associerad till muskelstyrka och muskelömhet för att få en tydligare bild av effekterna / Introduction: Effects of plyometric training to improve athletic performance such as explosive strength and power development are well-documented. However, less is known about the effects of aquatic plyometric training. Previous research suggests that it appears to have similar effects as land-based plyometric training. Purpose: The purpose of the literature review was to investigate if there is an effect of aquatic plyometric training on jump height, muscle strength and muscle soreness. Another aim was to compare the effects of plyometric training in water with land-based plyometric training on jump height, muscle strength and muscle soreness. Method: A systematic literature search was conducted in the scientific databases Pubmed and Web of Science. In addition, all references were manually searched on the articles that met the inclusion criteria. Results: The literature review shows that aquatic plyometric training seems to have an effect on jump height. Muscle strength and muscle soreness showed no clear outcome. Aquatic plyometric training seems to have the same effect on jump height and muscle strength as land-based plyometric training. Aquatic plyometric training seems to give less muscle soreness compared to land-based plyometric training. Conclusion: More research is necessary to determine which factors make aquatic plyometric training as effective as land-based plyometric training to improve jump height. More research is needed on aquatic plyometric training associated with muscle strength and muscle soreness to get a better understanding of the effects.

Bakgrund: Idrott kan utföras i många olika former och av en bred population. I flera idrotter är det fördelaktigt att ha god spänst och/eller snabbhet. Flera olika fysiska faktorer har påverkan på snabbhet och spänst, däribland explosivitet och muskelstyrka. Plyometrisk träning (PT) är en träningsform där Stretch-shortening-cycle (SSC) utnyttjas. SSC beskrivs som en muskulärt förlängande (excentrisk) rörelse följt av en muskulärt förkortande (koncentrisk) rörelse som syftar till att träna explosivitet.  Syfte: Analysera vilken effekt plyometrisk träning har på spänst och snabbhet hos idrottare, jämfört med ordinarie idrottsträning samt förekomst av skador Metod: En systematisk litteraturstudie som utgår från databaserna PubMed, PEDro, Cochrane Library och Cinahl. Studiernas kvalitet granskades med TESTEX och tillförlitligheten enligt GRADEstud.  Resultat: Nio randomiserade kontrollerade studier inkluderades i litteraturöversikten. Studiekvalitén var mellan 8-12 poäng enligt TESTEX. Studiernas tillförlitlighet enligt GRADEstud var mycket låg (+). Studiernas resultat var varierande gällande signifikans för PT och dess effekt för spänst och snabbhet hos idrottare jämfört med kontrollgrupp. Ingen studie rapporterade skada i samband med PT. Konklusion: De studier som analyserades bedömdes ha, på grund av olikheter i intervention och resultat, en låg evidensgrad. PT har viss effekt på spänst och snabbhet hos idrottare jämfört med kontrollgrupp som utför ordinarie idrottsträning. Inga skador rapporterades i de inkluderade studierna. Fler homogena studier krävs för att klargöra PT´s effekt på spänst och snabbhet hos idrottare. / Background: Sports can be performed in many forms and is being performed by a wide population. In different sports it’s beneficial to have good jumping ability and to be fast. Many physical factors affect the ability to jump and sprint, where muscle strength and explosiveness are two of them. Plyometric training (PT) is a training form that utilizes the stretch-shortening-cycle (SSC). SSC is an eccentric muscle contraction followed by concentric contraction of the same muscle that aims to train muscle explosiveness.    Objective: Evaluate the effect of plyometric training on jumping ability and sprinting within athletes compared with athletes only performing ordinary sport training.  Method: A systematic review. The search was performed on the databases PubMed, PEDro, Cochrane Library and Cinahl. The included studies quality was examined with TESTEX and the reliability with GRADEstud.  Results: Nine randomized controlled trials were included. The quality of the studies varied between 8 to 12 points. The reliability, examined with GRADEstud, was deemed very low (+). The effect of PT on jumping and sprinting for athletes compared with the control groups varied. None of the studies reported injuries associated with PT. Conclusion: The studies included had, due to differences in intervention and results, a low level of evidence. PT has a certain effect on jumping ability and sprinting for athletes compared with athletes only performing ordinary sport training. No injuries were reported by the studies included. More homogeneous studies are required to clarify the effect of PT on jump ability and sprint in athletes.

Introdução: o processo fisiológico de envelhecimento traduz-se em diversas alterações estruturais do sistema musculoesquelético. Estas, por sua vez, acarretam em modificações funcionais que se repercutem na dependência do senescente, determinando a diminuição da sua qualidade de vida. Das estratégias existentes para atenuar os efeitos da senescência o treinamento de potência tem sido apontado como preferido. Existem, contudo, indícios de que um treinamento baseado na potencialização da ação do ciclo alongamento-encurtamento seja uma melhor escolha. Hipóteses do estudo: pelos resultados obtidos em intervenções similares, hipotetiza-se que as participantes do protocolo de intervenção proposto apresentarão um aumento da densidade mineral óssea, do volume muscular, da capacidade funcional e melhora de alguns parâmetros biomecânicos da marcha, bem como da sua qualidade de vida. Objetivos: o objetivo geral do presente trabalho é, portanto, propor um modelo de treinamento fundamentado na potencialização da ação do ciclo alongamento-encurtamento e averiguar os seus efeitos em parâmetros selecionados da morfologia osteomuscular, capacidade funcional e qualidade de vida de idosas. Materiais e Métodos: 21 idosas sedentárias (66,9±4,2 anos) executaram o protocolo proposto durante 20 semanas, tendo os efeitos na densidade mineral óssea de fêmur, coluna, tíbia e rádio; efeitos na composição corporal, na força, no equilíbrio, na marcha, na flexibilidade e na qualidade de vida comparados aos efeitos obtidos pelo grupo controle (N=17, 65,0±3,4 anos), que não alterou o seu nível de atividade física. O protocolo de intervenção, composto por onze exercícios de força realizados com o intuito de potencializar a ação do ciclo alongamento-encurtamento, que apresentava duas modalidades de salto (salto vertical com contramovimento e drop jump), exigia a realização da fase concêntrica na maior velocidade possível. Resultados: quando comparado com o grupo controle, o grupo experimental apresentou alterações significantes (p<0,05) na densidade mineral óssea de coluna (g=1,06) e sua microarquitetura (g=0,80), na microarquitetura da tíbia (g=0,82), na força máxima (g=2,39) e potência (g=1,38) de extensores de joelho, na velocidade máxima de marcha (g=0,96), na flexibilidade de membros inferiores (g=1,05) e superiores (g=0,86) e no domínio Atividades passadas, presentes e futuras da qualidade de vida (g=1,08). Conclusão: os resultados apontam para a eficácia da proposta de intervenção, apresentando-se como uma nova estratégia para atenuar e até mesmo reverter algumas perdas estruturais e funcionais impostas pelo processo de envelhecimento / Introduction: the physiological aging process induces several structural changes in the musculoskeletal system. These, in turn, result in functional changes that are reflected in the senescent dependency, determining the reduction in their quality of life. Power training has been identified as ideal to mitigate the effects of aging. However, there are indications that an intervention based on the potentiation of the stretch-shortening cycle action is a better choice. Study hypotheses: the participants of the proposed intervention will increase their bone mineral density, muscle volume, functional capacity and will show some improvement in their gait, as well as in their quality of life. Purposes: the main objective of this study was to propose a training model based in the potentiation of the stretch-shortening cycle action and assess its effects on selected parameters of musculoskeletal morphology, functional capacity and quality of life of elderly women. Methods: 21 sendentary elderly women (66.9 ± 4.2 years) performed the proposed intervention protocol for 20 weeks and the effects on bone mineral density of the femur, spine, tibia and radio; effects on body composition, strength, balance, gait, flexibility and quality of life were compared to the effects obtained by the control group (N = 17, 65.0 ± 3.4 years) that did not change their level of physical activity. The program was composed by eleven strength exercises performed in order to enhance stretch-shortening cycle action, had two jump exercises (vertical jump with countermovement and drop jump) and had the concentric phase of the movements performed as fast as possible. Results: when compared to the control group the experimental group showed significant changes (p <0.05) in bone mineral density of the spine (g = 1.06) and its microarchitecture (g = 0.80), the microarchitecture of the tibia (g = 0.82), the knee extensors maximum force (g = 2.39) and power (g = 1.38), the maximum walking speed (g = 0.96), the lower (g = 1.05) and upper (g = 0.86) limbs flexibility and in the domain past, present and future activities of the quality of life (g = 1.08). Conclusion: the results point to the effectiveness of the proposed intervention, suggesting it as a new strategy to slow down and even reverse some structural and functional losses imposed by the aging process

A estratégia de corrida utilizada durante uma prova de média e longa duração é dependente de fatores fisiológicos e psicológicos, sendo esses expressos de maneira integrada e consciente pela percepção subjetiva de esforço (PSE) e pelas sensações afetivas. A economia de corrida (EC) tem sido apontada por ter uma importante participação nos ajustes da estratégia de prova. Nesse sentido, a melhora na EC poderia alterar a PSE e o afeto durante a corrida e consequentemente a estratégia utilizada pelo atleta. Uma vez que o treinamento pliométrico tem sido demonstrado por melhorar a EC em corredores, o presente estudo teve como objetivo verificar se as mudanças na EC induzidas pelo treinamento pliométrico poderiam alterar a estratégia de prova em corrida de 10km contrarrelógio. Concluíram o estudo 28 corredores divididos em dois grupos, controle (C, n = 13) e treinamento pliométrico (TP, n=15). Ambos os grupos mantiveram suas rotinas de treinamento, porém o grupo TP realizou duas sessões semanais de treinamento pliométrico, durante oito semanas. Foram avaliados antes e após o tratamento experimental: o desempenho, a estratégia de prova, a PSE e o afeto durante uma corrida de 10km contrarrelógio; a altura, o tempo de contato com o solo e o índice de força reativa durante o salto em profundidade (SP) e a distância nos cinco saltos horizontais; a economia de corrida a 10km/h (EC10) e 12km/h (EC12) e o VO2 na velocidade média da prova (VM10); o VO2máx, o pico de velocidade na esteira (PV) e a velocidade do VO2max (vVO2máx) em um teste máximo; a força dinâmica máxima no teste de 1RM no leg-press 45º e a contração voluntária isométrica máxima no dinamômetro isocinético; o stiffness do tendão patelar, a espessura dos tendões patelar e calcâneo e a arquitetura muscular do vasto lateral e do gastrocnêmico. Os principais resultados mostram que o treinamento pliométrico melhorou a EC10 em 3,6% (p = 0,05) e a EC12 em 4,9% (p = 0,01). No entanto, não alterou a PSE, o afeto ou o padrão estratégia de prova utilizada durante a corrida. Entretanto, quando apenas os atletas responsivos ao TP (EC >3,5%, n = 11) foram avaliados, observamos maior velocidade média durante a segunda metade da corrida e melhor desempenho (1,6%, p = 0,01). O treinamento pliométrico melhorou a altura do SP (7,2%, p = 0,004), o VO2máx (3,4%, p = 0,03) e o PV (1,6%, p = 0,02). Foi observada maior espessura do tendão patelar na região distal (10,1%, p = 0,05) e menor ângulo de penação no músculo gastrocnêmio (-11,1%, p = 0,04). Em conclusão, a melhora na EC induzida pelo treinamento pliométrico não alterou o padrão de estratégia de prova utilizada durante uma corrida de 10km contrarrelógio. No entanto, permitiu que o atleta mantivesse maiores velocidades durante a segunda metade da prova. Os efeitos do treinamento pliométrico sobre a EC podem ter sido induzidos pela melhora na utilização do ciclo alongamento-encurtamento decorrente da redução no ângulo de penação dos fascículos no músculo gastrocnêmio / During middle and long distance races the pacing strategy is dependent on physiological and psychological factors which are expressed in a conscious way by the RPE and the affective feelings. The running economy (RE) has been suggested to be an important factor in the pacing strategy control. Improvements in RE may change the RPE and affective feeling during running which could change the pattern of the pacing strategy. Since the plyometric training has been shown to be an effective method to improve the RE, the aim of this study was to verify if the improvement of RE after a plyometric training program could change the pacing strategy during 10-km time-trial running. Twenty eight runners were divided into two groups, control (C, n=13) and plyometric training (TP, n=15). All of the athletes maintained their running training routines; however, the PT performed two sessions/week of plyometric training during eight weeks. Performance, pacing strategy, RPE and affective feelings during the 10-km time-trial running; the jump high, time of ground contact and reactive strength index in drop-jump and the distance of horizontal five bounds; RE to 10km/h (RE10) and 12km/h (RE12) and the VO2 to 10-km running average speed (VM10); VO2max, peak of velocity (PV) and velocity of VO2max (vVO2max) in a treadmill progressive maximal test; one repetition maximum strength in a 45º leg-press and the maximum voluntary isometric contraction (CVIM) in a isokinetic dynamometry; patellar tendon stiffness, patellar and calcaneus tendon thickness and muscle architecture of vastus lateralis and gastrocnemius muscles were analyzed pre and post experimental treatment. The main results showed that the plyometric training improved the RE10 (3.6%; p = 0.05) and RE12 (4.9%; p = 0.01). Nevertheless, it did not change the RPE, affective feelings or pacing strategy during the 10-km running. When just the responsive athletes (EC >3.5%, n = 11) were analyzed we observed higher average speed during the second part of the running and better performance (1.6%, p = 0.01). Drop-jump performance (7.2%, p = 0.004), VO2max (3.4%, p=0.03) and PV (1.6%, p=0.02) were also improved. It was observed increased of distal patellar tendon thickness (10.1%, p = 0.05) and a lower pennation angle in the gastrocnemius muscle (-11,1%, p = 0,04). In conclusion, the RE improvement did not change the pacing strategy during a 10-km time-trial running. However, the athletes were able to maintain higher speeds during the second part of the running and improve their performance. The effects of plyometric training on RE seems to be associated to stretch-shortening cycle improvement induced by changes in pennation angle of the gastrocnemius muscle