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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Estudo de diferentes protocolos para a determinação do lactato mínimo em eqüinos em exercício: comparação com a máxima fase estável de lactato

Miranda, Maria Cristiane Pestana Chaves [UNESP] 09 February 2010 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:31:11Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-02-09Bitstream added on 2014-06-13T19:25:57Z : No. of bitstreams: 1 miranda_mcpc_dr_jabo.pdf: 867069 bytes, checksum: ab8ce7d5342cc255565a24babaf8554c (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Testes que avaliam o desempenho e direcionam a intensidade de treinamento de cavalos, como a aferição do limiar de lactato (LL), são muito úteis na medicina esportiva equina. O presente estudo visa determinar se a velocidade correspondente à concentração de lactato mínimo (VLACMIN) é dependente do protocolo utilizado. A VLACMIN determinada por meio de 5 protocolos (P1 – P5) foram comparados com a velocidade obtida no Teste da Máxima Fase Estável de Lactato (VMAFEL). Oito cavalos árabes treinados foram submetidos a várias sessões para determinação da VMAFEL e comparados com 5 protocolos diferentes. Estes protocolos incluíram um período de aquecimento, seguido de um galope de alta intensidade. Após a corrida, a velocidade foi reduzida para 4 m.s-1. Em P1, P2 e P3 o incremento de velocidade foi fixado em 0,5 m.s -1 e as durações das etapas foram de 3, 5 e 7 min, respectivamente. Em P2, P4 e P5, a duração das etapas foi fixada em 5 min, e o incremento de velocidade foi de 0,5; 1,0; e 1,5 m.s-1, respectivamente. A VLACMIN foi determinada pela aplicação de uma função polinomial de segundo grau. A média e desvio-padrão da VLACMIN dos valores de P1, P2 e P3 e do VMAFEL foram respectivamente: 5,61 ± 0,12 m.s-1; 5,26 ± 0,17 m.s-1; 4,96 ± 0,36 m.s-1; 5,48 ± 0,18 m.s-1 e houve diferença significativa quando comparamos VMAFEL e P3 . A média e desvio-padrão da VLACMIN dos valores de P2 , P4 e P5 e do VMAFEL foram respectivamente: 5,26 ± 0,17 m.s-1; 5,84 ± 0,45 m.s-1; 5,99 ± 0,43 m.s-1; 5,48 ± 0,18 m.s-1, e houve diferença significativa quando comparamos VMAFEL e P5. É possível concluir que a capacidade aeróbia mensurada por meio do método VLACMIN é dependente da duração da etapa, e do incremento da velocidade, nas condições analisadas. / Tests to evaluate the performance and direct the intensity of the horses´ training, such as the determination of the lactate threshold (LT), hold a great importance in the equestrian sports medicine. The present study aims at determining whether the speed corresponding to the minimum lactate concentration (VLACMIN) is dependent on the protocol used. The VLACMIN determined through 5 protocols (P1 – P5) were compared with the speed obtained in the Lactate Maximum Stable Phase Test (VMFEL). Eight trained Arabian horses underwent several sessions for the VMFEL determination and compared with 5 different protocols. These protocols included a warm-up period, followed by a high-intensity galloping. After the run, the speed was reduced to 4 m.s-1. In P1, P2 and P3 the speed increment was established at 0.5 m.s -1 and the phase durations were of 3, 5 and 7 min, respectively. In P2, P4 and P5, the phases duration was established at 5 min, and the speed increment was of 0.5; 1.0; and 1.5 m.s-1, respectively. The VLACMIN was determined through the application of a second-degree polynomial function. The mean and standard deviation of the VLACMIN of the P1, P2 and P3 values, as well as of the VMFEL, were respectively: 5.61 ± 0.12 m.s-1; 5.26 ± 0.17 m.s-1; 4.96 ± 0.36 m.s-1; 5.48 ± 0.18 m.s-1 and there was significant difference when we compared VMFEL and P3 . The mean and standard deviation of the VLACMIN of the P2 , P4 and P5 values, as well as of the VMFEL, were respectively: 5.26 ± 0.17 m.s-1; 5.84 ± 0.45 m.s-1; 5.99 ± 0.43 m.s-1; 5.48 ± 0.18 m.s-1, and there was significant difference when we compared VMFEL and P5. It is possible to conclude that the aerobic capacity measured through the VLACMIN method is dependent on both the phase duration and the speed increment, in the conditions analyzed.
12

Plasma Lactate Accumulation During Running with Body Weight Unloading by LBPP

Rasmussen, Nicole Nevitt 09 July 2013 (has links) (PDF)
At any given running speed, weight support with a lower body positive pressure (LBPP) device (i.e. Alter-G treadmill) reduces V̇O2. However, it is unknown how application of LBPP during running impacts lactate metabolism, specifically lactate threshold. Purpose: To determine if body weight unloading with the Alter-G treadmill alters lactate threshold. Methods. Maximal aerobic capacity (V̇O2max) and lactate threshold (LT) was determined in 8 male subjects on an Alter-G treadmill at 100% and 80% body weight loading at 0% grade in a randomized crossover design. V̇O2max tests started at 7 mile h-1 and increase speed by 1 mile h-1 every 2 min till voluntary exhaustion and were separated by a minimum of 7 days. LT tests started at 5 mile h-1 and increased speed to 6, 7, 7.5, 8.0, 8.5, 9.0 (additional stages increase speed by 0.5 mile h-1) every 3 min until the subject reached ¡Ö85% of V̇O2max. LT tests were separated by a minimum 3 days. V̇O2, heart rate (HR), mean arterial blood pressure (MAP) and changes in Hct, [Hb], and total protein ([TP]) were determined on separate days in a randomized crossover design. Plasma lactate concentrations were determined from venous blood samples (4 ml) obtained at rest and during the last minute of each exercise stage. Lactate threshold was determined from a log-log plot of lactate concentration (mM) and relative V̇O2 (ml O2 min-1 kg-1 BM). Results. V̇O2max determined during running at 100% and 80% loading were similar (52.3 ± 0.9 and 52.7 ± 0.7 ml O2 min-1 kg-1 BM, respectively). The energy cost of running at 9 mile h-1 (all subjects completed stages between 5 and 9 mile h-1) was reduced by 12% at 80% body weight (37.2 ± 2.9 ml O2 min-1 kg-1 BM) compared to running at 100% body weight (42.3 ± 1.7 ml O2 min-1 kg-1 BM, <0.05). However, plasma lactate at 9 mile h-1 was similar during 80% and 100% body weight running (3.4 ± 0.4 and 3.1 ± 0.7 mM, respectively). Plasma lactate at a given V̇O2 was higher (p < 0.05) while running at 80% body weight compared to 100% body weight running. Calculated LT at 100% BW loading (36.3 ± 1.3 ml O2 min-1 kg-1 BM) was higher than 80% BW loading (32.2 ± 1.8 ml O2 min-1 kg-1 BM, p<0.05). During running at 80% BW HR was reduced compared to 100% BW running (p<0.05) however the MAP response was similar. During exercise the reduction in PV, at any given V̇O2 was larger at 80% BW compared to 100% BW running (p<0.001). Conclusion. During running, BW unloading with LBPP decreased the energy cost of exercise but not lactate levels. Body weight unloading caused a lowering of the LT. The reduction in whole body energy cost was not associated with a reduction in the lactate production since plasma lactate accumulation at a given speed was similar with and without LBPP.
13

The importance of body-mass exponent optimization for evaluation of performance capability in cross-country skiing

Carlsson, Tomas January 2015 (has links)
Introduction Performance in cross-country skiing is influenced by the skier’s ability to continuously produce propelling forces and force magnitude in relation to the net external forces. A surrogate indicator of the “power supply” in cross-country skiing would be a physiological variable that reflects an important performance-related capability, whereas the body mass itself is an indicator of the “power demand” experienced by the skier. To adequately evaluate an elite skier’s performance capability, it is essential to establish the optimal ratio between the physiological variable and body mass. The overall aim of this doctoral thesis was to investigate the importance of body-mass exponent optimization for the evaluation of performance capability in cross-country skiing. Methods In total, 83 elite cross-country skiers (56 men and 27 women) volunteered to participate in the four studies. The physiological variables of maximal oxygen uptake (V̇O2max) and oxygen uptake corresponding to a blood-lactate concentration of 4 mmol∙l-1 (V̇O2obla) were determined while treadmill roller skiing using the diagonal-stride technique; mean oxygen uptake (V̇O2dp) and upper-body power output (Ẇ) were determined during double-poling tests using a ski-ergometer. Competitive performance data for elite male skiers were collected from two 15-km classical-technique skiing competitions and a 1.25-km sprint prologue; additionally, a 2-km double-poling roller-skiing time trial using the double-poling technique was used as an indicator of upper-body performance capability among elite male and female junior skiers. Power-function modelling was used to explain the race and time-trial speeds based on the physiological variables and body mass. Results The optimal V̇O2max-to-mass ratios to explain 15-km race speed were V̇O2max divided by body mass raised to the 0.48 and 0.53 power, and these models explained 68% and 69% of the variance in mean skiing speed, respectively; moreover, the 95% confidence intervals (CI) for the body-mass exponents did not include either 0 or 1. For the modelling of race speed in the sprint prologue, body mass failed to contribute to the models based on V̇O2max, V̇O2obla, and V̇O2dp. The upper-body power output-to-body mass ratio that optimally explained time-trial speed was Ẇ ∙ m-0.57 and the model explained 63% of the variance in speed. Conclusions The results in this thesis suggest that V̇O2max divided by the square root of body mass should be used as an indicator of performance in 15-km classical-technique races among elite male skiers rather than the absolute or simple ratio-standard scaled expression. To optimally explain an elite male skier’s performance capability in sprint prologues, power-function models based on oxygen-uptake variables expressed absolutely are recommended. Moreover, to evaluate elite junior skiers’ performance capabilities in 2-km double-poling roller-skiing time trials, it is recommended that Ẇ divided by the square root of body mass should be used rather than absolute or simple ratio-standard scaled expression of power output. / <p>Incorrect ISBN in printed thesis: 973-91-7601-270-3</p>
14

Efeitos do treinamento pliométrico em variáveis fisiológicas e neuromusculares de corredores de longa distância / Effects of plyometric training on physiologic and neuromuscular variables of long distance runners

Manechini, João Paulo Vieira 27 April 2017 (has links)
Com o objetivo de comparar os efeitos do treinamento de força rápida em parâmetros fisiológicos, mecânicos e neuromusculares de corredores de fundo, o presente trabalho contou com uma amostra de 18 atletas amadores do sexo masculino, praticantes de corrida de rua e com experiência em provas de longa distância (21km ou acima). A amostra foi selecionada para o grupo \"treinamento de força rápida\", (RPG - grupo experimental) ou \"exercícios educativos técnicos de corrida\" (RTG - grupo controle), que realizaram seis semanas de exercícios distintos. No intuito de avaliar o desempenho em variáveis-chave para o rendimento de fundistas, os sujeitos foram submetidos a uma série de testes em dois momentos distintos: após a semana de aprendizagem e adaptação aos exercícios (pré) e ao final das seis semanas dos protocolos propostos (pós). A bateria de testes foi composta por: testes de saltos verticais (Altura [H], Potência Pico [PP] e Potência Relativa [PR] do salto para as técnicas Squat Jump [SJ], Counter Movement Jump [CMJ] e Drop Jump 40cm [DJ40]); salto horizontal [SH] e salto sêxtuplo alternado [S6A] (distância saltada); uma repetição máxima no agachamento guiado (carga absoluta [1RM Abs.] e relativa à massa corporal [1RM Rel.]); teste de contração isométrica voluntária máxima (CIVM - força pico [Fpico], força pico relativa à massa corporal [Fpico R.], tempo da força pico [TFPICO] e taxa de desenvolvimento de força [TDF]); teste incremental de esteira (Velocidade Pico em Esteira [VPE] e Velocidade do Limiar de Lactato [vLL]); e tempo limite em esteira na VPE (Tlim). O tratamento estatístico foi realizado por meio do Software IBM® SPSS® Statistics v. 20.0, para Windows (IBM Corporation, Chicago, USA). A ANOVA Modelo Misto foi utilizada para as comparações das variáveis de desempenho entre momentos e entre grupos, com teste post-hoc de Bonferroni quando necessário, e o teste t de Student para amostras independentes foi realizado para comparar as variáveis relativas ao treinamento entre os grupos. Todas as variáveis foram submetidas aos testes estatísticos Cohen\'s \"d\" de Magnitude de Efeito (ES) e Probabilidade Quantitativa de Chances (QC). Foram encontradas diferenças estatisticamente significantes para as variáveis Altura de Salto e Potência Relativa para a técnica de salto vertical Squat Jump entre os momentos pré e pós treinamento para o grupo RPG (HSJ: F = 6,973; p = 0,018; PRSJ: F = 8,421; p = 0,01) e Altura de Salto e Potência Relativa para a técnica de salto vertical Counter Movement Jump entre os grupos RPG e RTG, após as seis semanas de exercícios (HCMJ: F = 6,163; p = 0,025; PRCMJ: F = 4,667; p = 0,046). Foi identificada diferença significativa para a variável \'tempo da Fpico\' (F = 7,731; p = 0,013) durante o teste de CIVM para o grupo RPG entre os momentos. O grupo Controle, ainda, apresentou queda na variável VPE após as seis semanas do protocolo (F = 5,493; p = 0,032), o que não foi observado no grupo Pliometria. Ademais, o grupo experimental apresentou redução nos valores de lactato sanguíneo nos minutos 1, 3 e 5 após o teste de Tlim (F = 16,858; p = 0,001; F = 8,406; p = 0,01; F = 12,092; p = 0,003, respectivamente). É possível concluir que o treinamento pliométrico foi superior ao protocolo de exercícios educativos no intuito de melhorar o desempenho da força rápida de membros inferiores, contribuindo, ainda, para a manutenção dos níveis iniciais de desempenho em corrida e a melhora da remoção do lactato sanguíneo, o que não pode ser observado no grupo RTG. / With the purpose to compare the effects of explosive-strength training in physiologic and neuromuscular variables of endurance runners, the present study accounted with 18 male amateur athletes experienced in long distance races (21km and above). The sample was divided between explosive-strength training - RPG (running plyometrics group) and technique exercises protocol - RTG (running techniques group), which performed six weeks of distinct exercise protocols. With the aim to evaluate key-variables for endurance running performance the subjects were submitted to batteries of assessments in two different moments: after the exercises adaptation week and right before the beginning of the protocols, and at the end of the exercise protocols. The assessments battery contained vertical jump tests (Jump Height [H], Peak Power [PP] and Relative Power [RP] for the techniques Squat Jump [SJ], Counter Movement Jump [CMJ] and Drop Jump 40cm [DJ40])/ horizontal long jump (SH) and sextuple jump alternating legs (S6A), one maximum repetition for squat at Smith Machine (absolute [1RM Abs.] and relative to body mass loads [1RM Rel.]), maximum voluntary isometric contraction test (MVIC - peak force [Fpico], peak force relative to body mass [Fpico R.], time to peak force [TFPICO] and rate of force development [TDF]); maximum incremental treadmill test (treadmill peak velocity [VPE] and lactate threshold velocity [vLL]), and time limit test at treadmill peak velocity (Tlim). The statistical procedures were performed at IBM® SPSS® Statistics Software v. 20.0, para Windows (IBM Corporation, Chicago, USA) The Mixed Model ANOVA was performed with dependent variables to identify time and group interactions, using the Bonferroni post-hoc test when necessary, while the training variables were analyzed by the Student\'s t test for independent samples. All data were also analyzed with Cohen\'s \"d\" Effect Size test (ES) and Probability of Quantitative Chances (QC). There were found in RPG significant differences for H and PR for Squat Jump technique between moments pre- and post-protocol (HSJ: F = 6,973; p = 0,018; PRSJ: F = 8,421; p = 0,01), and for the same variables for Counter Movement Jump technique between RPG and RTG (HCMJ: F = 6,163; p = 0,025; PRCMJ: F = 4,667; p = 0,046) after the exercise protocols. Also, significant difference was found for \'time to peak force\' variable (F = 7,731; p = 0,013) during the MVIC test for the group RPG between moments. Yet, the control group presented significant decrease of peak treadmill velocity in the moment post- compared to the pre-training (F = 5,493; p = 0,032), which was not observed in the experimental group. Still, the experimental group presented lower values for lactate concentrations 1, 3 and 5 minutes after Tlim test (F = 16,858; p = 0,001; F = 8,406; p = 0,01; F = 12,092; p = 0,003, respectively). It is possible to conclude that the plyometric training performed by the RPG was superior to the technique exercises protocol in the objective of increasing lower-limbs explosive-strength parameters, contributing to the maintenance of running performance and a better lactate clearance capacity, which did not happen in the RTG.
15

Comparação de diferentes métodos lactacidêmicos e glicêmicos de determinação do limiar anaeróbio em eqüinos

Soares, Otávio Augusto Brioschi [UNESP] 16 May 2008 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:23:46Z (GMT). No. of bitstreams: 0 Previous issue date: 2008-05-16Bitstream added on 2014-06-13T19:50:57Z : No. of bitstreams: 1 soares_oab_me_jabo_prot.pdf: 1519067 bytes, checksum: 98437b3bc201f8ee82ba7715b0f41aed (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O esporte eqüestre vem exigindo um grau crescente de profissionalismo no mundo todo. Testes de desempenho, como a aferição do Limiar anaeróbio (LA), inserem-se neste contexto. Este trabalho comparou sete protocolos de mensuração do LA, cinco lactacidêmicos (V2, V4, LAI, LAI0,5, Lacmin) e dois glicêmicos (LGI e Glicmin). Todos foram comparados a Máxima fase estável do lactato (MFEL), protocolo padrão de aferição do LA. Catorze eqüinos Puro Sangue Árabe foram utilizados, entre machos e fêmeas. As médias e desvios-padrão das velocidades associadas aos testes foram: V2 = 9,49 ± 0,83 m/s, V4 = 10,83 ± 0,71 m/s, VLAI = 9,62 ± 0,91 m/s, VLAI0,5 = 10,21 ± 0,80 m/s, VLacmin = 7,49 ± 0,55 m/s, VLGI = 7,69 ± 1,68 m/s, VGlicmin = 8,31 ± 1,64 m/s e VMFEL = 6,06 ± 0,51 m/s. Somente a VLacmin não diferiu da VMFEL, além de obter correlação significativa com a mesma de ρ = 0,76 (Correlação de Spearman). A Tendência e os Limites de Concordância entre a VLacmin e a VMFEL foram de 1,43; 0,79 e 2,05. Além de predizer velocidades diferentes da VMFEL, os limiares LAI, LGI e Glicmin apresentaram dificuldades operacionais. As diferenças entre as velocidades preditas pelos protocolos V2, V4, LAI e LAI0,5, LGI e Glicmin a VMFEL podem ser parcialmente explicadas por variações de composição de protocolo e dificuldades operacionais. Apesar de não diferirem estatisticamente, as VLacmin e as VMFEL apresentaram baixa concordância, o que provavelmente pode ser melhorado com ajustes finos no protocolo do Lacmin. / Equestrian sports are demanding a growing degree of professionalism all over the world. Performance tests, as Anaerobic threshold (AT) assessment, are inserted in that context. The present study compared seven protocols for anaerobic threshold assessment: five of them using the lactacidemia (V2, V4, IAT, IAT0.5 and Lacmin) and two glicemia (IGT and Glicmin). All of them were compared to the Maximal Lactate Steady State (MLSS), the gold standard for AT assessment. Fourteen Arabian horses, males and females were submitted to the protocols. Velocity means and standard deviation associated to each protocol were: V2 = 9.49 ± 0.83; V4 = 10.83 ± 0.71; VIAT = 9.62 ± 0.91; VIAT0,5 = 10.21 ± 0.80; VLacmin = 7.49 ± 0.55; VIGT = 7.69 ± 1.68; VGlicmin = 8.31 ± 1.64 e VMLSS = 6.06 ±0.51. Only VLacmin did not differ from VMLSS, moreover, they correlate significantly with ρ = 0.76 (Spearman correlation). Bias ant Limits of Agreement of the two methods were 1.43; 0.79 and 2.05. Besides they predicted different velocities when compared to VMLSS, IAT, IGT and Glicmin showed operational difficulties. The differences between the velocities associated with the several protocols and the VMLSS could be partially attributed to protocol components variations and some operational difficulties. Regardless the statistical equality, VLacmin and VMLSS revealed poor agreement, what could probably be improved with adjustments in the Lacmin protocol.
16

Limiar de variabilidade da freqüência cardíaca em diferentes protocolos ergométricos / Heart rate variability threshold in different ergometric protocols

Fronchetti, Lenise 22 February 2008 (has links)
Made available in DSpace on 2016-12-06T17:07:16Z (GMT). No. of bitstreams: 1 Lenise.pdf: 896604 bytes, checksum: ed6dc8456789694dd0332aad347e316a (MD5) Previous issue date: 2008-02-22 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The heart rate variability (VFC) decreases gradually during progressive exercise, which tends to stabilization in intermediate loads. Initially, the possibility of identification of a threshold of this variable (LiVFC1), assumed as demarcating of the transition of the vagal withdrawal for the predominance of the sympathetic activity in the control of the FC was demonstrated. Later, a possibility of a second point of transition was presented (LiVFC2). The objective of this research was to obtein more evidences of validity of the determination of this LiVFC, verifying the influence of the protocol of test in the diverse employed methods. Twenty one healthy subjects (24,8 ± 5,2 years; 76,7 ± 11,4 kg; 178,8 ± 7,8 cm) were submitted randomly to three experimental tests in an ergometer cycle: PAi5w/i ; PB30w/1 and PC45w/3 . The VFC - SD1 index of the Poincaré plots - (Polar® S810i) and blood lactate concentrations was measured (YSI@1500 Sport). Determination of LiVFC1 was considered by these methods: 1°) LiVFCLIM - SD1 minor the 3 ms; 2°) LiVFCTUL - difference between the SD1 of two consecutive stages < 1 ms; of LiVFC2: 1°) LiVFC2LIM - subdivision of curve of VFC in two straight lines, from the LiVFCLIM. The lactate thresholds was identified from the following method for LL1 : 1°) LLINADIR - smaller value equivalent of [La] /load; 2°) LL1FIXO - 2 mmol.1-1 for LL2: 1°) LL2THO - previous load to two consecutive increases, higher or equal the1 mmol.1-¹ ; 2°) LL2FIXO - 4 mmol-1-1. In analysis intra-protocol for the first threshold of transition (LT1), it was verified that the referring load to the LiVFCLIM method was similar between the protocols; whereas, in the LiVFCTUL the values of PC45w/3 was greater and different of the PA15w/1 (p&#8804; 0,05). Moreover, it was verified, that as much under effect of the increment and/or duration of stage, the LiVFC1 followed the alterations in the LL1. The distinct methods of LT1, it was observed that are in comparable levels in the PA15w/&#305; (r = 0,45 - 0,47; p&#8804; 0,05) and in the PB30w/1. On the other hand, the second threshold of transition (LT2), the load in the LjVFC2LIM presented higher values in the PB30w/1 compared with PA15w/&#305; (p &#8804; 0,05). To testing it influences the distinct protocols, the LiVFC2 LIM varied contrary direction the alterations in the LL2. The diverse methods of the LT2 differ in the three protocols, but they present moderate degree of association (r = 0,43 - 0,72). These data show that, the spite of the evidences of that the LiVFCLIM is not dependent protocol, is necessary caution in the use of this as an indicator of aerobic fitness, which had low the association to the LL1 . On the other hand, the LiVFC2LIM suffers modifications because the alteration in the amplitude and duration of the protocols, however, shows enough discriminatory power of the aerobic fitness, that exactly situated in distinct intensity of the LL2. / A variabilidade da freqüência cardíaca (VFC) diminui gradativamente durante exercício progressivo, com tendência a uma estabilização em cargas intermediárias. Inicialmente, foi demonstrada a possibilidade de identificação de um primeiro limiar desta variável (LiVFC1), assumido como demarcador da transição da retirada vagal para a predominância da atividade simpática no controle da FC. Posteriormente, foi apresentada a possibilidade de um segundo ponto de transição (LiVFC2). O objetivo deste estudo foi obter evidências adicionais de validade na determinação destes LiVFC, verificando a influência do protocolo de teste nos diversos critérios empregados. Vinte e um sujeitos saudáveis (24,8 ± 5,2 anos; 76,7 ± 11,4 kg; 178,8 + 7,8 cm) foram submetidos aleatoriamente a três testes experimentais em cicloergômetro: PA15w/1 ; PB30w/1 ; e PC45w/3 . Foram medidas a VFC índice SD1 da plotagem de Poincaré (Polar® S810i) e concentrações sangüíneas de lactato (YSI@1500 Sport). Para determinação do LiVFC1 considerou-se os métodos: 1°) LiVFCLIM SD 1 inferior a 3 ms; 2°) LiVFCTUL diferença entre o SD1 de dois estágios consecutivos for menor que 1 ms; e para o LiVFC2: 1°) LiVFC2LIM subdivisão da curva de VFC em duas retas, a partir do LiVFCLIM . Os limiares de lactato foram identificados a partir dos seguintes critérios para LL1: 1°) LLINADIR - menor valor equivalente de [La]/carga; 2°) LL1FIXO - 2 mmol.1-¹; e para LL: 1°) LL2THO carga que precede dois aumentos consecutivos, superiores ou iguais a 1 mmol.1-¹ ; 2°) LL2FIXO 4 mmol.1-¹. Na análise intra-protocolo para o primeiro limiar de transição (LT1), verificou-se que a carga referente ao método LiVFCLIM foi similar entre os protocolos; enquanto que, no LiVFCTUL os valores do PC45w/3 foram superiores e diferentes do PA15w/1 (p&#8804; 0,05). Além disso, verificou-se, que tanto sob efeito da amplitude quanto da duração do estágio, os LiVFC1 acompanharam as alterações nos LL1. Para os distintos critérios de LT1, observou-se que estão em intensidades semelhantes no PA15w/&#305; (r = 0,45 0,47; p&#8804; 0,05) e no PB30w/1 . Por outro lado, para o segundo limiar de transição (LT2), a carga no LiVFC2LIM apresentou valores maiores no PB30w/1 comparada aos do PA15w/1 (p&#8804; 0,05). Ao se testar a influência dos distintos protocolos, o LiVFC2 LIM variou em magnitude e direção contrária as alterações no LL2. Os diversos métodos do LT2 diferem nos três protocolos, mas apresentam moderado grau de associação (r = 0,43 a 0,72). Desse modo, pode-se concluir que a despeito das evidências de que o LiVFCLIM não é protocolo-dependente, é necessário cautela na utilização deste como variável indicadora da aptidão aeróbia devido à baixa associação aos LL1. Contudo, o LiVFC2 LIM sofre modificações com as alterações na amplitude e duração dos protocolos, no entanto, apresenta razoável poder discriminatório da aptidão aeróbia, mesmo que situado em intensidade distinta dos LL2.
17

Comparação de diferentes métodos lactacidêmicos e glicêmicos de determinação do limiar anaeróbio em eqüinos /

Soares, Otávio Augusto Brioschi. January 2008 (has links)
Orientador: Antonio de Queiroz Neto / Banca: José Corrêa de Lacerda Neto / Banca: Benedito Sérgio Denadai / Resumo: O esporte eqüestre vem exigindo um grau crescente de profissionalismo no mundo todo. Testes de desempenho, como a aferição do Limiar anaeróbio (LA), inserem-se neste contexto. Este trabalho comparou sete protocolos de mensuração do LA, cinco lactacidêmicos (V2, V4, LAI, LAI0,5, Lacmin) e dois glicêmicos (LGI e Glicmin). Todos foram comparados a Máxima fase estável do lactato (MFEL), protocolo padrão de aferição do LA. Catorze eqüinos Puro Sangue Árabe foram utilizados, entre machos e fêmeas. As médias e desvios-padrão das velocidades associadas aos testes foram: V2 = 9,49 ± 0,83 m/s, V4 = 10,83 ± 0,71 m/s, VLAI = 9,62 ± 0,91 m/s, VLAI0,5 = 10,21 ± 0,80 m/s, VLacmin = 7,49 ± 0,55 m/s, VLGI = 7,69 ± 1,68 m/s, VGlicmin = 8,31 ± 1,64 m/s e VMFEL = 6,06 ± 0,51 m/s. Somente a VLacmin não diferiu da VMFEL, além de obter correlação significativa com a mesma de ρ = 0,76 (Correlação de Spearman). A Tendência e os Limites de Concordância entre a VLacmin e a VMFEL foram de 1,43; 0,79 e 2,05. Além de predizer velocidades diferentes da VMFEL, os limiares LAI, LGI e Glicmin apresentaram dificuldades operacionais. As diferenças entre as velocidades preditas pelos protocolos V2, V4, LAI e LAI0,5, LGI e Glicmin a VMFEL podem ser parcialmente explicadas por variações de composição de protocolo e dificuldades operacionais. Apesar de não diferirem estatisticamente, as VLacmin e as VMFEL apresentaram baixa concordância, o que provavelmente pode ser melhorado com ajustes finos no protocolo do Lacmin. / Abstract: Equestrian sports are demanding a growing degree of professionalism all over the world. Performance tests, as Anaerobic threshold (AT) assessment, are inserted in that context. The present study compared seven protocols for anaerobic threshold assessment: five of them using the lactacidemia (V2, V4, IAT, IAT0.5 and Lacmin) and two glicemia (IGT and Glicmin). All of them were compared to the Maximal Lactate Steady State (MLSS), the gold standard for AT assessment. Fourteen Arabian horses, males and females were submitted to the protocols. Velocity means and standard deviation associated to each protocol were: V2 = 9.49 ± 0.83; V4 = 10.83 ± 0.71; VIAT = 9.62 ± 0.91; VIAT0,5 = 10.21 ± 0.80; VLacmin = 7.49 ± 0.55; VIGT = 7.69 ± 1.68; VGlicmin = 8.31 ± 1.64 e VMLSS = 6.06 ±0.51. Only VLacmin did not differ from VMLSS, moreover, they correlate significantly with ρ = 0.76 (Spearman correlation). Bias ant Limits of Agreement of the two methods were 1.43; 0.79 and 2.05. Besides they predicted different velocities when compared to VMLSS, IAT, IGT and Glicmin showed operational difficulties. The differences between the velocities associated with the several protocols and the VMLSS could be partially attributed to protocol components variations and some operational difficulties. Regardless the statistical equality, VLacmin and VMLSS revealed poor agreement, what could probably be improved with adjustments in the Lacmin protocol. / Mestre
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Efeitos do treinamento pliométrico em variáveis fisiológicas e neuromusculares de corredores de longa distância / Effects of plyometric training on physiologic and neuromuscular variables of long distance runners

João Paulo Vieira Manechini 27 April 2017 (has links)
Com o objetivo de comparar os efeitos do treinamento de força rápida em parâmetros fisiológicos, mecânicos e neuromusculares de corredores de fundo, o presente trabalho contou com uma amostra de 18 atletas amadores do sexo masculino, praticantes de corrida de rua e com experiência em provas de longa distância (21km ou acima). A amostra foi selecionada para o grupo \"treinamento de força rápida\", (RPG - grupo experimental) ou \"exercícios educativos técnicos de corrida\" (RTG - grupo controle), que realizaram seis semanas de exercícios distintos. No intuito de avaliar o desempenho em variáveis-chave para o rendimento de fundistas, os sujeitos foram submetidos a uma série de testes em dois momentos distintos: após a semana de aprendizagem e adaptação aos exercícios (pré) e ao final das seis semanas dos protocolos propostos (pós). A bateria de testes foi composta por: testes de saltos verticais (Altura [H], Potência Pico [PP] e Potência Relativa [PR] do salto para as técnicas Squat Jump [SJ], Counter Movement Jump [CMJ] e Drop Jump 40cm [DJ40]); salto horizontal [SH] e salto sêxtuplo alternado [S6A] (distância saltada); uma repetição máxima no agachamento guiado (carga absoluta [1RM Abs.] e relativa à massa corporal [1RM Rel.]); teste de contração isométrica voluntária máxima (CIVM - força pico [Fpico], força pico relativa à massa corporal [Fpico R.], tempo da força pico [TFPICO] e taxa de desenvolvimento de força [TDF]); teste incremental de esteira (Velocidade Pico em Esteira [VPE] e Velocidade do Limiar de Lactato [vLL]); e tempo limite em esteira na VPE (Tlim). O tratamento estatístico foi realizado por meio do Software IBM® SPSS® Statistics v. 20.0, para Windows (IBM Corporation, Chicago, USA). A ANOVA Modelo Misto foi utilizada para as comparações das variáveis de desempenho entre momentos e entre grupos, com teste post-hoc de Bonferroni quando necessário, e o teste t de Student para amostras independentes foi realizado para comparar as variáveis relativas ao treinamento entre os grupos. Todas as variáveis foram submetidas aos testes estatísticos Cohen\'s \"d\" de Magnitude de Efeito (ES) e Probabilidade Quantitativa de Chances (QC). Foram encontradas diferenças estatisticamente significantes para as variáveis Altura de Salto e Potência Relativa para a técnica de salto vertical Squat Jump entre os momentos pré e pós treinamento para o grupo RPG (HSJ: F = 6,973; p = 0,018; PRSJ: F = 8,421; p = 0,01) e Altura de Salto e Potência Relativa para a técnica de salto vertical Counter Movement Jump entre os grupos RPG e RTG, após as seis semanas de exercícios (HCMJ: F = 6,163; p = 0,025; PRCMJ: F = 4,667; p = 0,046). Foi identificada diferença significativa para a variável \'tempo da Fpico\' (F = 7,731; p = 0,013) durante o teste de CIVM para o grupo RPG entre os momentos. O grupo Controle, ainda, apresentou queda na variável VPE após as seis semanas do protocolo (F = 5,493; p = 0,032), o que não foi observado no grupo Pliometria. Ademais, o grupo experimental apresentou redução nos valores de lactato sanguíneo nos minutos 1, 3 e 5 após o teste de Tlim (F = 16,858; p = 0,001; F = 8,406; p = 0,01; F = 12,092; p = 0,003, respectivamente). É possível concluir que o treinamento pliométrico foi superior ao protocolo de exercícios educativos no intuito de melhorar o desempenho da força rápida de membros inferiores, contribuindo, ainda, para a manutenção dos níveis iniciais de desempenho em corrida e a melhora da remoção do lactato sanguíneo, o que não pode ser observado no grupo RTG. / With the purpose to compare the effects of explosive-strength training in physiologic and neuromuscular variables of endurance runners, the present study accounted with 18 male amateur athletes experienced in long distance races (21km and above). The sample was divided between explosive-strength training - RPG (running plyometrics group) and technique exercises protocol - RTG (running techniques group), which performed six weeks of distinct exercise protocols. With the aim to evaluate key-variables for endurance running performance the subjects were submitted to batteries of assessments in two different moments: after the exercises adaptation week and right before the beginning of the protocols, and at the end of the exercise protocols. The assessments battery contained vertical jump tests (Jump Height [H], Peak Power [PP] and Relative Power [RP] for the techniques Squat Jump [SJ], Counter Movement Jump [CMJ] and Drop Jump 40cm [DJ40])/ horizontal long jump (SH) and sextuple jump alternating legs (S6A), one maximum repetition for squat at Smith Machine (absolute [1RM Abs.] and relative to body mass loads [1RM Rel.]), maximum voluntary isometric contraction test (MVIC - peak force [Fpico], peak force relative to body mass [Fpico R.], time to peak force [TFPICO] and rate of force development [TDF]); maximum incremental treadmill test (treadmill peak velocity [VPE] and lactate threshold velocity [vLL]), and time limit test at treadmill peak velocity (Tlim). The statistical procedures were performed at IBM® SPSS® Statistics Software v. 20.0, para Windows (IBM Corporation, Chicago, USA) The Mixed Model ANOVA was performed with dependent variables to identify time and group interactions, using the Bonferroni post-hoc test when necessary, while the training variables were analyzed by the Student\'s t test for independent samples. All data were also analyzed with Cohen\'s \"d\" Effect Size test (ES) and Probability of Quantitative Chances (QC). There were found in RPG significant differences for H and PR for Squat Jump technique between moments pre- and post-protocol (HSJ: F = 6,973; p = 0,018; PRSJ: F = 8,421; p = 0,01), and for the same variables for Counter Movement Jump technique between RPG and RTG (HCMJ: F = 6,163; p = 0,025; PRCMJ: F = 4,667; p = 0,046) after the exercise protocols. Also, significant difference was found for \'time to peak force\' variable (F = 7,731; p = 0,013) during the MVIC test for the group RPG between moments. Yet, the control group presented significant decrease of peak treadmill velocity in the moment post- compared to the pre-training (F = 5,493; p = 0,032), which was not observed in the experimental group. Still, the experimental group presented lower values for lactate concentrations 1, 3 and 5 minutes after Tlim test (F = 16,858; p = 0,001; F = 8,406; p = 0,01; F = 12,092; p = 0,003, respectively). It is possible to conclude that the plyometric training performed by the RPG was superior to the technique exercises protocol in the objective of increasing lower-limbs explosive-strength parameters, contributing to the maintenance of running performance and a better lactate clearance capacity, which did not happen in the RTG.
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Physiological demands of competitive elite cross-country skiing

Carlsson, Magnus January 2015 (has links)
Introduction Researchers have, for decades, contributed to an increased collective understanding of the physiological demands in cross-country skiing; however, almost all of these studies have used either non-elite subjects and/or performances that emulate cross-country skiing. To establish the physiological demands of cross-country skiing, it is important to relate the investigated physiological variables to the competitive performance of elite skiers. The overall aim of this doctoral thesis was, therefore, to investigate the external validity of physiological test variables to determine the physiological demands in competitive elite cross-country skiing. Methods The subjects in Study I – IV were elite male (I – III) and female (III – IV) cross-country skiers. In all studies, the relationship between test variables (general and ski-specific) and competitive performances (i.e. the results from competitions or the overall ski-ranking points of the International Ski Federation (FIS) for sprint (FISsprint) and distance (FISdist) races) were analysed. Test variables reflecting the subject’s general strength, upper-body and whole-body oxygen uptake, oxygen uptake and work intensity at the lactate threshold, mean upper-body power, lean mass, and maximal double-poling speed were investigated. Results The ability to maintain a high work rate without accumulating lactate is an indicator of distance performance, independent of sex (I, IV). Independent of sex, high oxygen uptake in whole-body and upper-body exercise was important for both sprint (II, IV) and distance (I, IV) performance. The maximal double-poling speed and 60-s double-poling mean power output were indicators of sprint (IV) and distance performance (I), respectively. Lean mass was correlated with distance performance for women (III), whereas correlations were found between lean mass and sprint performance among both male and female skiers (III). Moreover, no correlations between distance performance and test variables were derived from tests of knee-extension peak torque, vertical jumps, or double poling on a ski-ergometer with 20-s and 360-s durations (I), whereas gross efficiency while treadmill roller skiing showed no correlation with either distance or sprint performance in cross-country skiing (IV). Conclusion The results in this thesis show that, depending on discipline and sex, maximal and peak oxygen uptake, work intensity at the lactate threshold, lean mass, double-poling mean power output, and double-poling maximal speed are all externally valid physiological test variables for evaluation of performance capability among elite cross-country skiers; however, to optimally indicate performance capability different test-variable expressions should be used; in general, the absolute expression appears to be a better indicator of competitive sprint performance whereas the influence of body mass should be considered when evaluating competitive distance performance capability of elite cross-country skiers.
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The importance of body-mass exponent optimization for evaluation of performance capability in cross-country skiing

Carlsson, Tomas January 2015 (has links)
Introduction Performance in cross-country skiing is influenced by the skier’s ability to continuously produce propelling forces and force magnitude in relation to the net external forces. A surrogate indicator of the “power supply” in cross-country skiing would be a physiological variable that reflects an important performance-related capability, whereas the body mass itself is an indicator of the “power demand” experienced by the skier. To adequately evaluate an elite skier’s performance capability, it is essential to establish the optimal ratio between the physiological variable and body mass. The overall aim of this doctoral thesis was to investigate the importance of body-mass exponent optimization for the evaluation of performance capability in cross-country skiing. Methods In total, 83 elite cross-country skiers (56 men and 27 women) volunteered to participate in the four studies. The physiological variables of maximal oxygen uptake (V̇O2max) and oxygen uptake corresponding to a blood-lactate concentration of 4 mmol∙l-1 (V̇O2obla) were determined while treadmill roller skiing using the diagonal-stride technique; mean oxygen uptake (V̇O2dp) and upper-body power output (Ẇ) were determined during double-poling tests using a ski-ergometer. Competitive performance data for elite male skiers were collected from two 15-km classical-technique skiing competitions and a 1.25-km sprint prologue; additionally, a 2-km double-poling roller-skiing time trial using the double-poling technique was used as an indicator of upper-body performance capability among elite male and female junior skiers. Power-function modelling was used to explain the race and time-trial speeds based on the physiological variables and body mass. Results The optimal V̇O2max-to-mass ratios to explain 15-km race speed were V̇O2max divided by body mass raised to the 0.48 and 0.53 power, and these models explained 68% and 69% of the variance in mean skiing speed, respectively; moreover, the 95% confidence intervals (CI) for the body-mass exponents did not include either 0 or 1. For the modelling of race speed in the sprint prologue, body mass failed to contribute to the models based on V̇O2max, V̇O2obla, and V̇O2dp. The upper-body power output-to-body mass ratio that optimally explained time-trial speed was Ẇ ∙ m-0.57 and the model explained 63% of the variance in speed. Conclusions The results in this thesis suggest that V̇O2max divided by the square root of body mass should be used as an indicator of performance in 15-km classical-technique races among elite male skiers rather than the absolute or simple ratio-standard scaled expression. To optimally explain an elite male skier’s performance capability in sprint prologues, power-function models based on oxygen-uptake variables expressed absolutely are recommended. Moreover, to evaluate elite junior skiers’ performance capabilities in 2-km double-poling roller-skiing time trials, it is recommended that Ẇ divided by the square root of body mass should be used rather than absolute or simple ratio-standard scaled expression of power output. / <p>Incorrect ISBN in printed thesis: 973-91-7601-270-3</p>

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