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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

The effects of glycine-arginine-alpha-ketoisocaporic acid calcium on maximum strength and muscular endurance

Harris, Mareio Cortez 06 August 2011 (has links)
Glycine-arginine-alpha-ketoisocaporic acid calcium (GAKIC) is a product advertised to increase muscular endurance during exercise via metabolic intervention. Purpose: The purpose of this study was to determine the effect of GAKIC ingestion on maximum strength and muscular endurance. Methods: Utilizing a double-blinded, crossover design, participants completed an upper and lower body resistance exercise protocol once using 11.2gs GAKIC, and the other with a placebo. Results: An increase in maximum strength was observed in the 1RM portion of the lower body protocol phase with statistical trends in the lower body TLV portion of testing. No significant differences were found in upper body 1RM, upper body TLV, HR, BLa, and Glucose between conditions. Conclusion: We concluded that in this protocol, GAKIC increased maximum strength in the 1RM leg press exercise. Further research is encouraged in resistance exercise.
2

Hodnocení metodických postupů u shybu jako testu maximální síly vojáků AČR / The evaluation of methodology on pull up test as a test of maximum strength of Czech soldiars

Kouřil, František January 2013 (has links)
Titel: The evaluation of different test protocol of pull up exercise as a maximum strenth test in Czech Republic soldiers Goals: The aim of this study is to compare different methodological ways during pull up exercise as a test of uper externities and back maximum strenght. And to assesed which load to use in case of test reason. Ant find out, what influence has the soldiers equipment on strenght test. Method: The study is based on an experiment consisting in the performance of different testing protocols, the same group of probands and subsequent comparison probands ordinal position in selected test methodologies. Selected tests, the maximum number of pull-ups with their own weight, the maximum number of pull-ups with essential military equipment (15 kg), the maximum number of pull-ups with 40% of your own body weight, the maximum load lifted in pull up excercise and the absolute pull up, which was calculated on the maximum load lifted . Use was basic statistics and serial correlation by Kendall correlation coefficient. Results: Test with military equipment (load weighing 15 kg) correlated with the test pull up with its own body weight value τr = 0.83 for statistical significance level α = 0.05. Test the pull up with 40% correlated with test pull up with their own body weight value τr = 0.72, for...
3

Efeito agudo do exercício aeróbio com diferentes volumes no desempenho de força em indivíduos fisicamente ativos / Acute effect of aerobic exercise with different volumes on strength performance in physically active individuals

Silva, Natalia Ribeiro da 17 December 2015 (has links)
O treinamento concorrente (TC) é frequentemente utilizado por praticantes de atividades físicas e atletas com o intuito de desenvolver a força muscular e o condicionamento aeróbio. No entanto, essa estratégia de treinamento pode atenuar os ganhos de força e hipertrofia muscular em longo prazo, efeito este conhecido como fenômeno da interferência. Há indícios na literatura de que a magnitude da interferência pode ser dependente do volume em que o exercício aeróbio é realizado. Assim, o objetivo do presente estudo foi verificar o efeito do exercício aeróbio realizado com diferentes volumes no desempenho agudo de força máxima e de resistência de força dos membros inferiores. Homens fisicamente ativos (n=21) foram submetidos a seis condições experimentais realizadas em ordem aleatória, sendo três sessões de exercício aeróbio com volumes distintos (3km, 5km e 7km) seguidas pelo teste de força dinâmica máxima (1RM) e outras três sessões de exercício aeróbio com os volumes distintos seguidas pelo teste de resistência de força (4 séries de repetições máximas a 80% 1RM). Para o exercício aeróbio foi realizada a corrida contínua em esteira rolante a 90% do limiar anaeróbio (Lan) e os testes de força foram realizados no exercício leg press 45o. Para a comparação dos valores de 1RM, volume total (VT) e número de repetições máximas (NRM) da sessão de treinamento de força (TF) foi realizada uma análise de modelo misto tendo os volumes do exercício aeróbio como fator fixo e sujeitos como fator aleatório. Testes post-hoc com ajustamento de Tukey foram utilizados para comparações múltiplas. O nível de significância adotado foi de 5%. Não foram observadas diferenças nos valores de 1RM entre as condições. O VT e NRM das condições de 5km e 7km foram menores quando comparados com a condição controle. Ao passo que, o VT da condição de 7km foi menor em relação ao VT das condições de 3km e 5km; e o NRM da condição de 7km foi menor em relação ao NRM da condição de 3km. Não foram observadas diferenças no VT e NRM entre as condições de 3km e controle e entre as condições de 3km e 5km. Em conclusão, o desempenho da resistência de força foi prejudicado após a realização do exercício aeróbio e a ocorrência e a magnitude desta interferência dependeram do volume em que o exercício aeróbio foi realizado. Adicionalmente, o desempenho da força dinâmica máxima não foi prejudicado pela realização prévia do exercício aeróbio / Concurrent training (CT) is frequently utilized by physically active individuals and athletes in order to develop muscle strength and aerobic fitness. However, this training strategy may result in attenuation of the gains on strength and muscle hypertrophy in long term. This effect has been referred to as the interference phenomenon. There are indications that the magnitude of this interference may be dependent on the volume that aerobic exercise is performed. Thus, the aim of the present study was to verify the effect of aerobic exercise performed with different volumes on the acute performance of lower limbs maximum strength and strength endurance. Physically active men (n=21) were submitted to six experimental conditions performed in random order, three aerobic exercise sessions with different volumes (3km, 5km and 7km) followed by the maximum dynamic strength (1RM) test and three aerobic exercise sessions with different volumes followed by strength endurance test (4 sets of maximum repetitions at 80% 1RM). The aerobic exercise was a continuous treadmill run at 90% of the anaerobic threshold (AT) and all strength tests were performed in the leg press 45o. A mixed-model analysis with the volumes of aerobic exercise as a fixed factor and subject as a random factor was performed to compare 1RM values, total volume (TV) and maximum number of repetitions (MNR) of the strength training (ST) session. Post-hoc tests with Tukey adjustments were used for multiple comparisons. The significance level adopted was 5%. No differences were observed in 1RM values among conditions. The TV and MNR of the 5km and 7km conditions were lower when compared to the control condition. The TV of the 7km condition was lower than the 3km and 5km conditions; and the MNR of the 7km condition was lower than the 3km condition. No differences were observed in TV and MNR between the 3km and control conditions and between the 3km and 5km conditions. In conclusion, strength endurance performance was impaired when performed after aerobic exercise and the magnitude of this interference depended on the volume of the aerobic exercise. In addition, maximum dynamic strength performance was not affected by prior execution of aerobic exercise
4

Power Outputs among Explosive Athletes: Relationships to Maximum Strength, and Strategies for Improvement

Stone, Michael H., Stone, Margaret E. 01 May 2008 (has links)
No description available.
5

Peak Force and Rate of Force Development During Isometric Mid-Thigh Clean Pulls and Dynamic Mid-Thigh Clean Pulls Performed at Various Intensities

Kawamori, Naoki, Rossi, Steven J., Justice, Blake D., Haff, Erin E., Pistilli, Emido E., O'Bryant, Harold S., Stone, Michael H., Haff, G. Gregory 01 August 2006 (has links)
Eight male collegiate weightlifters (age: 21.2 ± 0.9 years; height: 177.6 ± 2.3 cm; and body mass: 85.1 ± 3.3 kg) participated in this study to compare isometric to dynamic force-time dependent variables. Subjects performed the isometric and dynamic mid-thigh clean pulls at 30–120% of their one repetition maximum (1RM) power clean (118.4 ± 5.5 kg) on a 61 X 121.9–cm AMTI forceplate. Variables such as peak force (PF) and peak rate of force development (PRFD) were calculated and were compared between isometric and dynamic conditions. The relationships between force-time dependent variables and vertical jump performances also were examined. The data indicate that the isometric PF had no significant correlations with the dynamic PF against light loads. On the one hand, there was a general trend toward stronger relationships between the isometric and dynamic PF as the external load increased for dynamic muscle actions. On the other hand, the isometric and dynamic PRFD had no significant correlations regardless of the external load used for dynamic testing. In addition, the isometric PF and dynamic PRFD were shown to be strongly correlated with vertical jump performances, whereas the isometric PRFD and dynamic PF had no significant correlations with vertical jump performances. In conclusion, it appears that the isometric and dynamic measures of force-time curve characteristics represent relatively specific qualities, especially when dynamic testing involves small external loads. Additionally, the results suggest that athletes who possess greater isometric maximum strength and dynamic explosive strength tend to be able to jump higher. Eight male collegiate weightlifters (age: 21.2 ± 0.9 years; height: 177.6 ± 2.3 cm; and body mass: 85.1 ± 3.3 kg) participated in this study to compare isometric to dynamic force-time dependent variables. Subjects performed the isometric and dynamic mid-thigh clean pulls at 30–120% of their one repetition maximum (1RM) power clean (118.4 ± 5.5 kg) on a 61 X 121.9–cm AMTI forceplate. Variables such as peak force (PF) and peak rate of force development (PRFD) were calculated and were compared between isometric and dynamic conditions. The relationships between force-time dependent variables and vertical jump performances also were examined. The data indicate that the isometric PF had no significant correlations with the dynamic PF against light loads. On the one hand, there was a general trend toward stronger relationships between the isometric and dynamic PF as the external load increased for dynamic muscle actions. On the other hand, the isometric and dynamic PRFD had no significant correlations regardless of the external load used for dynamic testing. In addition, the isometric PF and dynamic PRFD were shown to be strongly correlated with vertical jump performances, whereas the isometric PRFD and dynamic PF had no significant correlations with vertical jump performances. In conclusion, it appears that the isometric and dynamic measures of force-time curve characteristics represent relatively specific qualities, especially when dynamic testing involves small external loads. Additionally, the results suggest that athletes who possess greater isometric maximum strength and dynamic explosive strength tend to be able to jump higher.
6

Effect of Body Position on Force Production During the Isometric Midthigh Pull

Beckham, George K., Sato, Kimitake, Santana, Hugo A. P., Mizuguchi, Satoshi, Haff, G. Gregory, Stone, Michael H. 01 January 2018 (has links)
Various body positions have been used in the scientific literature when performing the isometric midthigh pull resulting in divergent results. We evaluated force production in the isometric midthigh pull in bent (125° knee and 125° hip angles) and upright (125° knee, 145° hip angle) positions in subjects with (>6 months) and without (<6 months) substantial experience using weightlifting derivatives. A mixed-design ANOVA was used to evaluate the effect of pull position and weightlifting experience on peak force, force at 50, 90, 200, and 250 ms. There were statistically significant main effects for weightlifting experience and pull position for all variables tested, and statistically significant interaction effects for peak force, allometrically scaled peak force, force at 200 ms, and force at 250 ms. Calculated effect sizes were small to large for all variables in subjects with weightlifting experience, and were small to moderate between positions for all variables in subjects without weightlifting experience. A central finding of the study is that the upright body position (125° knee and 145° hip) should be used given that forces generated are highest in that position. Actual joint angles during maximum effort pulling should be measured to ensure body position is close to the position intended.
7

Mechanical behavior of a bio-based composite : influences of production conditions

Hosseini Moghadam, Seyed Mazdak, Alshihabi, Mohamed January 2016 (has links)
Some mechanical properties of DuraPulp, a bio-based, bio-degradable composite made from polylactic acid (PLA) and pulp fibers, were determined. Focus was put on the conditions during productions whereby three different press times were studied. Additionally, two different material compositions (PLA to fiber ratios) were used. Uniaxial tensile tests with two different load rates, one and 50 mm/min, were performed. An increase in maximum strength and E-modulus of DuraPulp was observed by increasing the press time, while PLA content decreased the maximum strength and E modulus.
8

Efeito agudo do exercício aeróbio com diferentes volumes no desempenho de força em indivíduos fisicamente ativos / Acute effect of aerobic exercise with different volumes on strength performance in physically active individuals

Natalia Ribeiro da Silva 17 December 2015 (has links)
O treinamento concorrente (TC) é frequentemente utilizado por praticantes de atividades físicas e atletas com o intuito de desenvolver a força muscular e o condicionamento aeróbio. No entanto, essa estratégia de treinamento pode atenuar os ganhos de força e hipertrofia muscular em longo prazo, efeito este conhecido como fenômeno da interferência. Há indícios na literatura de que a magnitude da interferência pode ser dependente do volume em que o exercício aeróbio é realizado. Assim, o objetivo do presente estudo foi verificar o efeito do exercício aeróbio realizado com diferentes volumes no desempenho agudo de força máxima e de resistência de força dos membros inferiores. Homens fisicamente ativos (n=21) foram submetidos a seis condições experimentais realizadas em ordem aleatória, sendo três sessões de exercício aeróbio com volumes distintos (3km, 5km e 7km) seguidas pelo teste de força dinâmica máxima (1RM) e outras três sessões de exercício aeróbio com os volumes distintos seguidas pelo teste de resistência de força (4 séries de repetições máximas a 80% 1RM). Para o exercício aeróbio foi realizada a corrida contínua em esteira rolante a 90% do limiar anaeróbio (Lan) e os testes de força foram realizados no exercício leg press 45o. Para a comparação dos valores de 1RM, volume total (VT) e número de repetições máximas (NRM) da sessão de treinamento de força (TF) foi realizada uma análise de modelo misto tendo os volumes do exercício aeróbio como fator fixo e sujeitos como fator aleatório. Testes post-hoc com ajustamento de Tukey foram utilizados para comparações múltiplas. O nível de significância adotado foi de 5%. Não foram observadas diferenças nos valores de 1RM entre as condições. O VT e NRM das condições de 5km e 7km foram menores quando comparados com a condição controle. Ao passo que, o VT da condição de 7km foi menor em relação ao VT das condições de 3km e 5km; e o NRM da condição de 7km foi menor em relação ao NRM da condição de 3km. Não foram observadas diferenças no VT e NRM entre as condições de 3km e controle e entre as condições de 3km e 5km. Em conclusão, o desempenho da resistência de força foi prejudicado após a realização do exercício aeróbio e a ocorrência e a magnitude desta interferência dependeram do volume em que o exercício aeróbio foi realizado. Adicionalmente, o desempenho da força dinâmica máxima não foi prejudicado pela realização prévia do exercício aeróbio / Concurrent training (CT) is frequently utilized by physically active individuals and athletes in order to develop muscle strength and aerobic fitness. However, this training strategy may result in attenuation of the gains on strength and muscle hypertrophy in long term. This effect has been referred to as the interference phenomenon. There are indications that the magnitude of this interference may be dependent on the volume that aerobic exercise is performed. Thus, the aim of the present study was to verify the effect of aerobic exercise performed with different volumes on the acute performance of lower limbs maximum strength and strength endurance. Physically active men (n=21) were submitted to six experimental conditions performed in random order, three aerobic exercise sessions with different volumes (3km, 5km and 7km) followed by the maximum dynamic strength (1RM) test and three aerobic exercise sessions with different volumes followed by strength endurance test (4 sets of maximum repetitions at 80% 1RM). The aerobic exercise was a continuous treadmill run at 90% of the anaerobic threshold (AT) and all strength tests were performed in the leg press 45o. A mixed-model analysis with the volumes of aerobic exercise as a fixed factor and subject as a random factor was performed to compare 1RM values, total volume (TV) and maximum number of repetitions (MNR) of the strength training (ST) session. Post-hoc tests with Tukey adjustments were used for multiple comparisons. The significance level adopted was 5%. No differences were observed in 1RM values among conditions. The TV and MNR of the 5km and 7km conditions were lower when compared to the control condition. The TV of the 7km condition was lower than the 3km and 5km conditions; and the MNR of the 7km condition was lower than the 3km condition. No differences were observed in TV and MNR between the 3km and control conditions and between the 3km and 5km conditions. In conclusion, strength endurance performance was impaired when performed after aerobic exercise and the magnitude of this interference depended on the volume of the aerobic exercise. In addition, maximum dynamic strength performance was not affected by prior execution of aerobic exercise
9

Kvinnliga elitinnebandyspelares fysiska profil : En beskrivning av utespelare / The physiological profile of elite female floorballplayers : A study of field players

Sandlund, Stefan January 2018 (has links)
Bakgrund: Innebandy är en intensiv sport där snabba upprepade accelerationer och riktningsförändringar är viktiga ingredienser för framgång. Även om både förflyttningssnabbhet och uthållighet är viktiga för prestationen i innebandy, finns inga studier som undersöker hur de relaterar till varandra och andra viktiga fysiska kvaliteter. Syfte: Att beskriva kvinnliga elitinnebandyspelares fysiska egenskaper och undersöka korrelationen mellan snabbhet i förflyttningar, aerob uthållighet, maximal styrka och explosivitet. Metod:19 kvinnliga elitinnebandyspelare i åldern (medel (SD)) 21,8år (±2,15), längd 168,8cm (±5,8) långa och vikt 65,9 kg (±6,3), rekryterades till studien. Ett testbatteri genomfördes över två dagar och bestod av snabbhetstester (Acc10, Acc20m, Pro-agility), explosivstyrketester (SLH, SJ, CMJ, CMJ:A), maximalstyrketest (IPU) och aerob uthållighet (Beeptest). Korrelationen mellan testresultaten analyserades. Resultat: Det fanns starka korrelationer mellan förflyttningssnabbhet och prestationen explosiv styrka, utom mellan vertikalhopp med armsving (CMJ:A) och snabbhet i riktningsförändringar (Pro- agility). Isometrisk styrka (IPU) relaterade endast signifikant till snabbhet i riktningsförändringar (Pro-agility), vilket också aerob uthållighet (Beeptest) gjorde. Slutsats: För kvinnliga elitinnebandyspelare finns ett samband mellan explosiv styrka och snabbhet i alla förflyttningar, medan maximalstyrka endast verkar relatera till snabbhet i riktningsförändringar. Arbetsförmågan i aerob uthållighetsarbeten verkar inte påverka prestationen i snabbhet negativt, utan på den här prestationsnivån kan båda utvecklas till tillräcklig nivå. / Background: Floorball is an intense sport where rapid repeated accelerations and changes of direction are important ingredients for success. Although both the locomotion speed and endurance are essential for achievement in floorball, there are no studies examining how they relate to each other and other important physical qualities. Objective: To describe female elite Floorball player's physical properties and examine the correlation between locomotion speed, aerobic endurance, maximum strength and explosiveness. Method: 19 female elite Floorball players age (mean (±SD)) 21, 8 years (±2.15), height 168, 8 cm (±5.8) and weight (65.9 kg±6.3), were recruited to the study. A test battery was conducted over the span of two days and consisted of tests of locomotion speed (Acc10, Acc20, Pro-agility), explosive strength (SLH, SJ, CMJ, CMJ:A), maximum strength (IPU) and aerobic endurance (Beep test). The correlation between the test results were analyzed. Results: There were strong correlations between locomotion speed performance and explosive strength, except between vertical jump with arm swing (CMJ) and speed in changes of direction (the Pro agility). Isometric strength (IPU) significantly related to the speed in changes of direction (the Pro agility), as did aerobic endurance (Beeptest). Conclusion: For female elite Floorball players there seems to be a correlation between explosive strength and quickness in all types of locomotion, while the maximum strength only seems to relate to the speed in changes of directions. Work ability in aerobic endurance tasks does not seem to affect performance in locomotion speed, and at this performance level both can be developed to a sufficient level.
10

Styrkeförluster vid åldrande? : En tvärsnittsstudie om eventuella skillnader i styrkeförluster hos äldre seniorer / Loss of strength with ageing? : A cross-sectional study on possible differences in strength losses in older seniors

Hallgren, Hampus, Brostedt, Carl-Mikael January 2023 (has links)
Bakgrund: Äldre personer, 65 år och uppåt, bör vara fysiskt aktiva för ett hälsosammare och längre liv. Forskning har visat att muskelmassa och styrka minskar exponentiellt snabbare efter år 60 och muskelatrofi sker främst av typ 2 muskelfibrer. En minskad mängd muskelmassa är hos äldre starkt korrelerat med funktionsnedsättning, vilket resulterar i att regelbunden styrketräning därmed är en effektiv metod för att motverka sarkopeni hos äldre individer. Syfte: Syftet med studien var att studera kraftskillnader mellan olika åldersgrupper hos seniorer uppmätt på prestations-anpassat utomhusgym. Metod: Studien var en kvantitativ tvärsnittsstudie. Totalt deltog 35 personer, 21 kvinnor och 14 män, som fick utföra fysiska maxtester på labb och utomhusgym. Resultat: Mann Whitney U-testet visade skillnader i maxstyrka mellan män och kvinnor 65+ i alla statiska maxtester, på 0.001-nivån. Vid könsuppdelning av åldersgrupperna var det en skillnad mellan männen på 0.05-nivån i roddrag, p=0.039, och bänkpress, p=0.028. Spearmans korrelationstest visade ett negativt samband på 0.01-nivån, p=0.005 mellan ålder och STS r = -0,466. Slutsats: Konklusionen av vår studie är att det inte fanns någon betydande skillnad i maxstyrka mellan åldersgrupperna 65-75 och 75+. Det fanns en skillnad i maxstyrka mellan män och kvinnor över 65 år. Vid könsuppdelning av åldersgrupperna fanns det en skillnad i maxstyrka mellan män 65-75 och män 75+ i roddrag och bänkpress, men hos kvinnor fanns det ingen skillnad i maxstyrka mellan åldersgrupperna 65-75 och 75+. Utifrån resultaten i vår studie kan därmed slutsatsen dras att både äldre män och kvinnor behöver styrketräna för att behålla styrka vid åldrande. / Background: Older people, aged 65 and over, should be physically active for a healthier and longer life. Research has shown that muscle mass and strength decrease exponentially faster after the age of 60 and muscle atrophy occurs mainly in type 2 muscle fibres. A reduced amount of muscle mass in older people is strongly correlated with disability, resulting in regular strength training being an effective method to counteract sarcopenia in older individuals. Purpose: The purpose of the study was to study strength differences between different age groups in seniors measured in a performance-adapted outdoor gym. Method: The study was a quantitative cross-sectional study. A total of 35 participants, 21 women and 14 men, were asked to perform physical max tests in the lab and outdoor gym. Results: The Mann Whitney U test showed differences in maximum strength between men and women 65+ in all static max tests, at the 0.001 level. When splitting the age groups by gender, there was a difference between men at the 0.05 level in the rowingpull, p=0.039, and benchpress, p=0.028. Spearman's correlation test showed a negative correlation at the 0.01 level, p=0.005 between age and STS r = -0.466. Conclusion: The conclusion of our study is that there was no significant difference in maximum strength between the 65-75 and 75+ age groups. There was a difference in maximum strength between men and women over 65 years of age. When dividing the age groups by gender, there was a difference in maximum strength between men 65-75 and men 75+ in the rowing pull and bench press, but in women there was no difference in maximum strength between the age groups 65-75 and 75+. Based on the results of our study, it can therefore be concluded that both older men and women need strength training to maintain strength during aging.

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