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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.
1

Efeito de diferentes frequências de treinamento no desempenho de força máxima e hipertrofia muscular em indivíduos treinados / Effect of different training frequencies on maximal strength performance and muscle hypertrophy in trained individuals

Neves, Ricardo Pereira 06 March 2018 (has links)
Introdução: O estado de treinamento é um dos fatores que podem influenciar na frequência de treinamento, e de fato, evidências têm sugerido que sujeitos previamente treinados tenham necessidade de realizar o treinamento de força (TF) em maiores frequências semanais, com intuito de aumentar o desempenho de força e a massa muscular. Objetivo: Comparar as alterações no desempenho de força dinâmica máxima (1RM) dos membros inferiores e na área de secção transversa (AST) do músculo quadríceps femoral, após a realização de um programa de treinamento de força distribuído em diferentes frequências semanais, em um grupo de indivíduos previamente treinados em força. Materiais e Métodos: A amostra foi composta por 24 sujeitos do sexo masculino, com idade entre 18 e 35 anos, que participaram de um programa de TF de nove semanas. Os sujeitos foram distribuídos em duas condições: TFVE - treinamento de força com volumes equalizados e, TFVN - treinamento de força com volumes não equalizados. O protocolo de TF utilizou o exercício leg press 45º (unilateral) como único exercício, e deste modo, cada um dos membros inferiores (MMII) foi submetido a uma das frequências semanais de treinamento propostas (i.e., uma e três vezes). O teste de 1RM no exercício leg press 45º (unilateral) e as medidas de AST do músculo quadríceps femoral foram realizados nos momentos pré e pós-treinamento. Resultados: Os aumentos nos valores de 1RM foram significantes (p<0,001) e similares, nas diferentes frequências de TF tanto da condição TFVE (16,0 ± 10,0% e 17,2 ± 12,2% para uma e três vezes por semana, respectivamente) quanto da condição TFVN (19,4 ± 13,1% e 24,6 ± 14,2% para uma e três vezes por semana, respectivamente). Para AST, também houve aumentos significantes (p<0,001) e similares, nas diferentes frequências de TF tanto da condição TFVE (2,1 ± 2,1% e 2,0 ± 2,8% para uma e três vezes por semana, respectivamente) quanto da condição TFVN (1,5 ± 2,6% e 4,1 ± 5,0% para uma e três vezes por semana, respectivamente). Quando o effect size (ES) e o intervalo de confiança (IC) foram calculados, pôde-se observar que a maior frequência de treinamento apresentou melhores resultados nos valores de 1RM e AST, somente quando foi permitida a realização de um maior volume de treinamento (i.e., TFVN). Conclusão: O TF realizado três vezes por semana demonstrou aumentos de 1RM e AST similares àquele realizado somente uma vez, independentemente ou não da equalização do volume de treinamento. Quando a maior frequência de TF pôde proporcionar um maior volume total de treinamento, valores significantes do IC do ES foram observados para ambas as adaptações. Portanto, se indivíduos treinados necessitam de maiores volumes de treinamento para que sejam observados aumentos tanto na força quanto na massa muscular, alternativas como o aumento da frequência do TF podem ser consideradas / Introduction: Training status is one of the factors that may influence training frequency, and in fact, evidence has suggested that previously trained subjects need to perform strength training (ST) at higher weekly frequencies, in order to increase strength and muscle mass. Objective: To compare the changes in lower limbs maximal dynamic strength (1RM) and in the cross-sectional area (CSA) of the quadriceps femoris muscle, after performing a strength training program distributed at different weekly frequencies in a group of previously strength trained individuals. Materials and Methods: The sample was composed of 24 male subjects, aged between 18-35 years, who participated in a 9-week ST program. The subjects were divided into two conditions: STEV - strength training with equalized volumes and, STUV - strength training with unequalized volumes. The ST protocol used the leg press 45º exercise (unilateral) as the only exercise, and thus, each lower limb was submitted to one of the proposed weekly training frequencies (i.e., one and three times). The 1RM test in the leg press 45º exercise (unilateral) and the CSA measurements of the quadriceps femoris muscle were performed at the pre and post training moments. Results: The increases in the 1RM values were significant (p<0.001) and similar, in the different ST frequencies of the STEV condition (16.0 ± 10.0% and 17.2 ± 12.2% for one and three times a week, respectively) and STUV condition (19.4 ± 13.1% and 24.6 ± 14.2% for one and three times a week, respectively). For CSA, there were also similar and significant increases (p<0.001), in the different ST frequencies of the STEV condition (2.1 ± 2.1% and 2.0 ± 2.8% for one and three times a week, respectively) and STUV condition (1.5 ± 2.6% and 4.1 ± 5.0% for one and three times a week, respectively). When the effect size (ES) and the confidence interval (CI) were calculated, it was observed that the higher training frequency presented better results in the 1RM and CSA values, only when it was allowed to perform a higher training volume (i.e., STUV). Conclusion: The ST performed three times a week, showed 1RM and CSA increases similar the one performed only once, regardless of training volume equalization. When the higher frequency of ST allowed a greater total volume of training, significant values of the CI of the ES were observed for both adaptations. Therefore, if trained individuals require higher training volumes to increase strength and muscle mass, alternatives such as increased ST frequency can be considered
2

Frequency of in-season strength and power training for rugby league

Masters, Haydn, res.cand@acu.edu.au January 2001 (has links)
The purpose of this study was to determine the contribution of different in-season strength and power training frequencies to strength and power performance over the course of a 22 week rugby league competition period. Twenty-eight male (n=28) participants, with both high and low strength pre-training status, were divided into three groups following a 15 week pre-season strength and power training programme. A four week periodised in-season strength and power training programme, with intensities ranging from 75-100%, was cycled for the 22 week competition season. Strength and power training was conducted one day.week(-1) by the first high pre-training status group (HTFL, n=11), and two day.week(-1) by the second high pre-training status group (HTF2, n=9). The low pre-training status group (LTF1, n=8) performed the same strength and power training frequency and programme as HTF1. Training intensity (% 1RM) and volume (sets x repetitions) of in-season strength and power training sessions were standardised for both groups during each training week. Strength, power, and speed data were collected pre-season, and four times during the in-season period. No differences were found between HTF1 and HTF2 in performance variables throughout the 22-week in-season period. Both HTF1 and HTF2 displayed similar significant detraining effects in strength, power, and speed, regardless of in-season training frequency (p<0.05). LTF1 showed no change from pre-season strength and power performance following 22 weeks of the competition period (p<0.05). It was concluded that in-season strength and power training frequency may have a limited role in determining the success of the in-season strength and power training programme in highly trained footballers. The results of the present study suggest a number of factors other than in-season strength and power training frequency may affect in-season strength and power performance and detraining in high strength pre-training status athletes. The effect the start of a competition period has on dynamic athletic performance needs further investigation.
3

Efeito de diferentes frequências de treinamento no desempenho de força máxima e hipertrofia muscular em indivíduos treinados / Effect of different training frequencies on maximal strength performance and muscle hypertrophy in trained individuals

Ricardo Pereira Neves 06 March 2018 (has links)
Introdução: O estado de treinamento é um dos fatores que podem influenciar na frequência de treinamento, e de fato, evidências têm sugerido que sujeitos previamente treinados tenham necessidade de realizar o treinamento de força (TF) em maiores frequências semanais, com intuito de aumentar o desempenho de força e a massa muscular. Objetivo: Comparar as alterações no desempenho de força dinâmica máxima (1RM) dos membros inferiores e na área de secção transversa (AST) do músculo quadríceps femoral, após a realização de um programa de treinamento de força distribuído em diferentes frequências semanais, em um grupo de indivíduos previamente treinados em força. Materiais e Métodos: A amostra foi composta por 24 sujeitos do sexo masculino, com idade entre 18 e 35 anos, que participaram de um programa de TF de nove semanas. Os sujeitos foram distribuídos em duas condições: TFVE - treinamento de força com volumes equalizados e, TFVN - treinamento de força com volumes não equalizados. O protocolo de TF utilizou o exercício leg press 45º (unilateral) como único exercício, e deste modo, cada um dos membros inferiores (MMII) foi submetido a uma das frequências semanais de treinamento propostas (i.e., uma e três vezes). O teste de 1RM no exercício leg press 45º (unilateral) e as medidas de AST do músculo quadríceps femoral foram realizados nos momentos pré e pós-treinamento. Resultados: Os aumentos nos valores de 1RM foram significantes (p<0,001) e similares, nas diferentes frequências de TF tanto da condição TFVE (16,0 ± 10,0% e 17,2 ± 12,2% para uma e três vezes por semana, respectivamente) quanto da condição TFVN (19,4 ± 13,1% e 24,6 ± 14,2% para uma e três vezes por semana, respectivamente). Para AST, também houve aumentos significantes (p<0,001) e similares, nas diferentes frequências de TF tanto da condição TFVE (2,1 ± 2,1% e 2,0 ± 2,8% para uma e três vezes por semana, respectivamente) quanto da condição TFVN (1,5 ± 2,6% e 4,1 ± 5,0% para uma e três vezes por semana, respectivamente). Quando o effect size (ES) e o intervalo de confiança (IC) foram calculados, pôde-se observar que a maior frequência de treinamento apresentou melhores resultados nos valores de 1RM e AST, somente quando foi permitida a realização de um maior volume de treinamento (i.e., TFVN). Conclusão: O TF realizado três vezes por semana demonstrou aumentos de 1RM e AST similares àquele realizado somente uma vez, independentemente ou não da equalização do volume de treinamento. Quando a maior frequência de TF pôde proporcionar um maior volume total de treinamento, valores significantes do IC do ES foram observados para ambas as adaptações. Portanto, se indivíduos treinados necessitam de maiores volumes de treinamento para que sejam observados aumentos tanto na força quanto na massa muscular, alternativas como o aumento da frequência do TF podem ser consideradas / Introduction: Training status is one of the factors that may influence training frequency, and in fact, evidence has suggested that previously trained subjects need to perform strength training (ST) at higher weekly frequencies, in order to increase strength and muscle mass. Objective: To compare the changes in lower limbs maximal dynamic strength (1RM) and in the cross-sectional area (CSA) of the quadriceps femoris muscle, after performing a strength training program distributed at different weekly frequencies in a group of previously strength trained individuals. Materials and Methods: The sample was composed of 24 male subjects, aged between 18-35 years, who participated in a 9-week ST program. The subjects were divided into two conditions: STEV - strength training with equalized volumes and, STUV - strength training with unequalized volumes. The ST protocol used the leg press 45º exercise (unilateral) as the only exercise, and thus, each lower limb was submitted to one of the proposed weekly training frequencies (i.e., one and three times). The 1RM test in the leg press 45º exercise (unilateral) and the CSA measurements of the quadriceps femoris muscle were performed at the pre and post training moments. Results: The increases in the 1RM values were significant (p<0.001) and similar, in the different ST frequencies of the STEV condition (16.0 ± 10.0% and 17.2 ± 12.2% for one and three times a week, respectively) and STUV condition (19.4 ± 13.1% and 24.6 ± 14.2% for one and three times a week, respectively). For CSA, there were also similar and significant increases (p<0.001), in the different ST frequencies of the STEV condition (2.1 ± 2.1% and 2.0 ± 2.8% for one and three times a week, respectively) and STUV condition (1.5 ± 2.6% and 4.1 ± 5.0% for one and three times a week, respectively). When the effect size (ES) and the confidence interval (CI) were calculated, it was observed that the higher training frequency presented better results in the 1RM and CSA values, only when it was allowed to perform a higher training volume (i.e., STUV). Conclusion: The ST performed three times a week, showed 1RM and CSA increases similar the one performed only once, regardless of training volume equalization. When the higher frequency of ST allowed a greater total volume of training, significant values of the CI of the ES were observed for both adaptations. Therefore, if trained individuals require higher training volumes to increase strength and muscle mass, alternatives such as increased ST frequency can be considered
4

The influence of sex, training status, and fatty acid supplementation on T-lymphocyte populations at rest and in response to acute exercise

Brown, Frankie F. January 2014 (has links)
This series of studies began with an examination of the effects of training status (Tr vs UTr) and sex on the resting levels and redistribution of senescent (CD28-CD57+) and naïve (CD28+CD57-) T-lymphocytes (CD4+, CD8+) following a treadmill test to volitional exhaustion. In this first study exercise elicited a redistribution of senescent CD4+, CD8+ and naïve CD4+,CD8+ T-lymphocytes. UTr had a higher proportion of senescent and a lower proportion of naïve CD8+ T-lymphocytes than Tr. Males had a higher proportion of senescent and lower proportion of naïve T-lymphocytes than females with the highest percentage of senescent and lowest percentage of naïve T-lymphocytes observed in UTr males. CMV was a covariate in the senescent and naïve CD8+ T-lymphocytes. This study highlighted important sex and training status differences in the senescent and naïve T-lymphocyte redistribution in response to exercise. These findings led on to an investigation of the T-lymphocyte (CD4+, CD8+, γδ+) response to a period of 2 weeks increased volume training (39% increase in volume) in trained females (Tr, n=13) compared to a period of 2 weeks habitual activity in female controls (UTr, n=13). This second study observed no difference in the resting T-lymphocyte profile from the pre to post increased volume training period. The resting number of CD3+ and proportion of γδ+ T-lymphocytes was greater in the Tr compared to the UTr. The resting proportion of CD4+T-lymphocytes and the CD4+:CD8+ ratio was greater in the UTr compared to the Tr. CMV was a covariate in the analysis of CD8+, CD28+ CD8+, and naïve CD8+ T-lymphocyte cell numbers but not in the analysis of T-lymphocyte proportions. The increased volume training period had no effect on resting T-lymphocyte populations in Tr females, and T-lymphocyte populations also did not change with 2 weeks of habitual exercise in UTr. The total energy, carbohydrate and protein intake was greater in Tr compared to the UTr during the increased volume training period and was greater than normal in the Tr group. These dietary influences may partly explain the absence of any change in T-lymphocyte proportions pre to post training period in Tr. Differences in the proportions of γδ+, CD4+ and the ratio of CD4+:CD8+ T-lymphocytes at rest between the Tr and UTr warrants further investigation. The final study of this series is presented in two parts. The first part focused on the influence of 4 weeks supplementation at 0.1g/kg body mass/day with n-3 polyunsaturated fatty acids (PUFA) as fish oil (FO, n=10), or short-chain saturated fatty acids (SFA) as coconut oil (CO, n=10) on T-lymphocyte (CD4+,CD8+, γδ+) differentiated populations at rest and in response to exercise in trained males. Changes were examined by Day (Baseline to pre supplementation, Pre Sup (4 week control period), and pre supplementation to post supplementation, Post Sup (4 week supplementation period)). During a 4 week baseline control period no changes were observed in the blood lipid profile in both FO and CO groups. During the control period a main effect of exercise was observed in all the CD3+ and γδ+ T-lymphocytes subsets. During the control period an interaction of group-by-day was observed in the senescent CD8+ T-lymphocytes from BL to Pre Sup the proportion and number decreased in the FO group and increased in the CO group. Inclusion of CMV as a covariate introduced a main effect of group on the CD4+ naïve proportions and cell counts and the group-by-day interaction observed on the CD8+ senescent T-lymphocyte proportions and cell counts disappeared. During the 4 week supplementation period this study observed an increase in the n-3 PUFAs, EPA (20:5n-3), DHA (22:6n-3) and DPA (22:5n-3) in the FO group but not in the CO group (with no changes in blood lipid profile on CO). During the supplementation period a main effect of exercise was observed in all the CD3+ and γδ+ T-lymphocyte subsets except for the proportion of CD8+ naïve T-lymphocytes. The proportion of CD8+ naïve T-lymphocytes was lower at rest and in response to exercise in FO and CO groups after supplementation. CMV was a significant covariate in senescent CD4+ T-lymphocyte cell counts. At the post exercise time point the γδ+ T-lymphocyte count increased in the FO group but decreased in the CO group, following the supplementation period. However, this observation did not quite reach statistical significance. Although a difference between the groups was evident for γδ+ T-lymphocyte count and proportion there was insufficient evidence to conclude whether the difference was supplement related. It would appear that dose, duration and type of fatty acids ingested could all be important in the overall response but these require further study. The second part of this final study investigated the influence of 4 week supplementation at 0.1g/kg body mass/day with n-3 polyunsaturated fatty acids (PUFA) as fish oil (FO, n=10) or short-chain saturated fatty acids (SFA) as coconut oil (CO, n=10) on plasma Th1 cytokine: IL-2, TNF- α and IFN-γ, and Th2 cytokine IL-4, IL-6 and IL-10 concentrations, and expression of the T-lymphocyte activation marker CD69 at rest and in response to exercise in trained males. Changes were examined by Day (Baseline to pre supplementation (4 week control period), and pre supplementation to post supplementation (4 week supplementation period)). This study observed an increase in n-3 PUFAs, EPA (20:5n-3), DHA (22:6n-3) and DPA (22:5n-3) in the FO group but not in the CO group. There was a significant mobilisation of activated CD4+ CD69+ and CD8+ CD69+ (P<0.05) T-lymphocyte numbers in response to exercise in both FO and CO groups. CMV infection was a significant covariate on the number and proportion of CD4+CD69+ T-lymphocytes (P<0.05) but not on the number or proportion of CD8+CD69+ T-lymphocytes. During the supplementation period there was a significant effect of Day on TNF-α, IL-6, IL-4 and IL-2 with IFN-γ and IL-10 trending towards a difference. The plasma cytokine concentration was greater at post supplementation compared to pre supplementation for both FO and CO groups. Latent CMV infection was a significant covariate for TNF-α, IL-6, IL-4, IL-2, IFN-γ and IL-10. In the current study we observed no evidence of a difference between the CO and FO groups for early T-lymphocyte activation marker or plasma cytokine concentrations despite the membrane lipid composition change over the 4 week supplementation period. It would appear that the plasma Th1 and Th2 cytokine concentration increased from pre supplementation to post supplementation on both PUFA and SFA, highlighting a potential link between fatty acid incorporation and cytokine expression that needs closer examination. The results of this series of studies highlight that sex and training status impact upon the T-lymphocyte pool at rest and in response to exercise. Increasing the volume of training for 2 weeks without dietary restriction does not alter the resting T-lymphocyte pool in trained females. Alterations to the T-lymphocyte pool at rest and in response to exercise are not related to FO or CO supplementation. Furthermore, the response of Th1, Th2 plasma cytokines, and the early activation marker CD69 at rest and in response to exercise does not differ between a group supplemented with FO compared to a group supplemented with CO it would appear that Th1 and Th2 plasma cytokines increase post supplementation in both groups. Particular avenues of interest for future research would be, to explore the sex differences in T-lymphocyte subsets at rest and in response to exercise, to determine whether these sex differences are key in susceptibility to disease/infection and to determine the tissue targets of lymphocytes mobilised during exercise.

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