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.

Ergogenic L-citrulline and malate are amino acids used in specific combination to effect muscular endurance during athletic performances. Purpose: The study aimed to investigate the ergogenic properties of citrulline-malate (CM) during a resistance training protocol. Methods: Utilizing a randomized, counterbalanced, double blind study, fifteen trained males completed a resistance training protocol once using placebo (PL) and once with CM (8.0g). Results: CM supplementation increased repetitions in chin-ups, reverse chin-ups, push-ups, and total trial repetitions. Blood lactate was significantly increased post-exercise compared to pre-exercise, but was not significantly different between CM and placebo. Further, a significant interaction effect was revealed for systolic blood pressure, a significant condition effect for diastolic blood pressure, and a significant time effect for HR. Post-hoc analysis revealed that SBP responses were more elevated in the placebo condition during recovery. Conclusion: Collectively, these novel findings suggest CM increases muscular endurance during upper body resistance exercise.

The purpose of the study was to determine the accuracy of 11 prediction equations in estimating the 1 repetition maximum (1RM) bench press from repetitions completed by collegiate football players (N = 69) using 225 lb. The demographic variables race, age, height, weight, fat-free weight, and percent body fat were measured to determine whether these variables increased the accuracy of the prediction equations; race was the most frequently selected variable in the regression analyses. The validity of the prediction equations was dependent upon the number of repetitions performed, i.e., validity was higher when fewer repetitions were completed. Explained variability of 1RM was slightly higher for all 11 equations when demographic variables were included. A new prediction equation was also developed using the number of repetitions performed and the demographic variables height and fat-free weight.

Pre-workout(PWO) är idag ett välkänt fenomen som med ökat användande varje år. I denna studie testas preworkout-preparatet Rampage™ som är ett av Sveriges mest använda preparat. Det finns för få studier som testar preworkout-preparat i samband med muskulär uthållighet och vår hypotes är att det är där pre-workout har som störst effekt. Syftet med den här studien är att undersöka hur Rampage™ påverkar muskulär uthållighet hos män i åldern 18 och uppåt. För att undersöka detta har ett experiment med dubbelblind crossover-design skapats, där 13 deltagare efter behandling av antingen placebo eller Rampage™, blivit utsatta för tre set knäböj, tre set armhävningar och tre set sit-ups var. Antalet repetitioner som utfördes användes sedan till statistisk analys och resultatet visade ingen signifikant skillnad mellan grupperna(p=0,858). Det finns några orsaker till varför det kan vara såhär och det finns anledning att fortsätta forska om det här specifikt. Vår hypotes att pre-workout påverkar muskulär uthållighet är fortfarande under prövning. / Pre-workout supplementation is today a well-known phenomenon ever increasing in popularity every year. In this study, we investigate Rampage™; a popular product in Sweden. There’s too few studies that investigate the link between pre-workout and strength training to failure and we believe that is where pre-workout is most effective. The aim of this study is to research Rampage’s™ effects on muscular endurance in male participants above the age group of 18. To do this a double-blind cross-over design has been applied to 13 participants who, unknowingly, either ingest a placebo or the actual pre-workout in order to do three sets of squats, three sets of push-ups and three sets of sit-ups. When they couldn’t perform one more repetition the set was concluded. The number of repetitions was later used for statistical analysis and we found no significance between the groups (p=0,858). There are some reasons this might be the case, and we believe this could be investigated further, although our hypothesis remains unproven.

The delayed occurrence of fatigue while maintaining submaximal force output is a function that could be driven by the central nervous system (CNS). It has been found previously that mean EMG amplitude increases with fatigue. Endurance time has also been found to increase over repeated testing. The purpose of this study was to compare the muscle activation patterns and endurance times after training of the AdP muscle. This study analyzed surface EMG of the adductor pollicis (AdP) muscle in young, healthy adults during a sustained submaximal isometric fatiguing contraction before and after 4 weeks of muscular endurance task training. Eight participants (training group: n = 4 and control group: n = 4) carried out maximal voluntary contractions (MVCs) while sustaining isometric force of 20% MVC of thumb adduction before and after the four weeks of endurance training. EMG, recorded through surface electrodes, was measured before and after training in an effort to detect a possible CNS training effect. The endurance training group trained the AdP muscle at 20% MVC every other day for 4 weeks. Average force was calculated over 5 second time bins every 5% of endurance time (20 time bins total). A significant increase in endurance time was seen in the training group of this study. A significant effect of change for pre and post-training mean EMG amplitude across the two groups was found (p < .001). A significant interaction effect between pre and post training and control groups was also found (p = .016). There was also a significant deficit in increases of mean amplitude between the first and last time bins of the endurance task (pre and post) after training. This indicates that there is an effect of training on increasing endurance time which can be exhibited through changes in mean EMG amplitude. / text

No description available.

This study investigated the assessment of muscular endurance using the Universal Gym. Subjects included 19 women and 151 men (18-30 years). Measures of muscular endurance were evaluated at various percentages of 1 RM on twelve exercise stations and it appears that a percentage of 1 RM ranging from .7 for the arms, .5 to .9 for the legs, and ,5 to .8 for the trunk is required to produce fatigue state in the necessary repetition range.

The present investigation was designed to examine the effects of the positive manipulation of information on self-efficacy and subsequent performance of 180 female subjects. High, moderate, and low self-efficacy subjects were randomly assigned to a treatment condition in a 3 x 4 x 3 (preexisting self-efficacy x efficacy information source x trials) factorial design. Information from the three efficacy sources of performance accomplishments, verbal persuasion, and vicarious experience was manipulated towards success after subjects completed a muscular leg endurance task. The results supported self-efficacy theory with high self-efficacy subjects extending their legs significantly longer than moderate and low self-efficacy subjects. However, subjects did not differentially [sic] respond to the manipulation of the efficacy information. Results are discussed in terms of efficacy as a mediator of performance on an endurance task as well as the lack of differential changes in efficacy based on the source from which that information is derived.

Submitted by leonardo Perinotto abdalla (leoabdalla@live.com) on 2018-03-16T15:22:43Z No. of bitstreams: 1 Dissertação .pdf: 4793508 bytes, checksum: 9e8ed8362972b0fe05f4c6d100e03979 (MD5) / Approved for entry into archive by Ana Paula Santulo Custódio de Medeiros null (asantulo@rc.unesp.br) on 2018-03-16T16:39:16Z (GMT) No. of bitstreams: 1 abdalla_lhp_me_rcla.pdf: 4789566 bytes, checksum: 85a14005b703aa3dd03acc7d79a891de (MD5) / Made available in DSpace on 2018-03-16T16:39:16Z (GMT). No. of bitstreams: 1 abdalla_lhp_me_rcla.pdf: 4789566 bytes, checksum: 85a14005b703aa3dd03acc7d79a891de (MD5) Previous issue date: 2018-02-28 / O objetivo deste estudo foi testar as hipóteses de que o torque critico (TC) (expresso como % de uma contração voluntária máxima, CVM) é maior para os flexores plantares (FP) com relação aos músculos extensores do joelho (EJ), enquanto o impulso acima do TC (W’) é maior para EJ do que FP. Assim, esperamos que a tolerância ao exercício seja maior para EJ do que FP somente durante o exercício realizado acima de TC. Após a determinação da CVM, 11 homens realizaram dois testes All-Out de 5 min para determinar TC e W’. Os onze sujeitos realizaram mais 5 testes isométricos intermitentes até a falha da tarefa, durante 5 visitas, + 5% TC e - 5% TC para ambos os músculos, e 1 teste para EJ na mesma intensidade de exercício em (% CVM) correspondente a + 5% TC do FP. Os onze participantes realizaram mais 4 testes isométricos intermitentes, até a exaustão, + 5% e - 5% do TC e 1 teste para EJ na intensidade do exercício (% CVM) correspondente a + 5% do TC do FP, para o EJ. O W '(7243,2 ± 1942,9 vs. 3357,4 ± 1132,3 N · m · s) e CT (84,4 ± 24,8 vs. 73,9 ± 19,5 N · m) foram significativamente menores para FP em comparação com EJ. A tolerância ao exercício foi significativamente mais longa para FP (300,7 ± 156,7 s) do que EJ (156,7 ± 104,3 s) em CVM semelhante (~60%) e significativamente menor para FP (300,7 ± 156,7 s) do que EJ (697,0 ± 243,7 s) na condição de + 5% do TC. No entanto, nenhuma diferença significativa foi observada para condição de - 5% do TC (EJ = 1030,2 ± 495,4 s vs. FP = 1028,3 ± 514,4 s). Assim, o limite de tolerância durante as contrações isométricas submáximas é influenciado pela CVM absoluta apenas durante o exercício realizado em intensidade acima do TC, o que parece ser explicado por diferenças nos valores de TC (expressos em % CVM) e o W’. / The objective of this study was to test the hypotheses that critical torque (CT) (expressed as % maximal voluntary contraction; MVC) is higher for plantar flexors (PF) than knee extensors (KE) muscles, whereas impulse above ET (W’) is higher for KE than PF. Thus, we expected that exercise tolerance would be longer for KE than PF only during the exercise performed above ET. After the determination of MVC, 11 men performed two 5-min all-out tests to determine ET and IET. Eleven participants performed a further 4 intermittent isometric tests, to exhaustion, at ET + 5% and ET – 5%, and 1 test for KE at the exercise intensity (%MVC) corresponding to ET + 5% of PF. The W’ (7243.2 ± 1942.9 vs. 3357.4 ± 1132.3 N·m·s) and CT (84.4 ± 24.8 vs. 73.9 ± 19.5 N·m) were significantly lower in PF compared with KE. The exercise tolerance was significantly longer for PF (300.7 ± 156.7 s) than KE (156.7 ± 104.3 s) at similar %MVC (�����60%), and significantly shorter for PF (300.7 ± 156.7 s) than KE (697.0 ± 243.7 s) at ET + 5% condition. However, no significant difference was observed for ET – 5% condition (KE = 1030.2 ± 495.4 s vs. PF = 1028.3 ± 514.4 s). Thus, the limit of tolerance during submaximal isometric contractions is influenced by absolute MVC only during exercise performed above ET, which seems to be explained by differences on both CT (expressed as %MVC) and W’ values.

Work-related musculoskeletal disorders (WMSDs) are prevalent in the workplace, and epidemiology studies show that these problems do not tend to diminish. While the use of new and advanced technology has substantially reduced the amount of physical workload, repetitive manual activities are still typically observed in various work settings. Despite their fairly low workload intensity, prolonged repetitive tasks have been associated with the development of musculoskeletal complaints and problems. Research on localized muscle fatigue (LMF) has been viewed as a viable endeavor toward understanding the processes and mechanisms associated with WMSDs. A mounting of evidence on local fatigue during sustained static work has been presented, but much less is known with respect to muscle fatigue during more complex activities. A study was conducted with the primary objectives of determining the repeatability of several commonly used fatigue measures, and to evaluate the presence of long-lasting effects of fatigue from different recovery periods. Based on low-level intermittent arm abductions, findings from this study demonstrated that the use of perceptions of muscular discomfort and muscle strength as fatigue measures was satisfactory. In contrast, electromyography (EMG)-based measures were characterized by a fairly low repeatability. The study also suggested that, whenever practical, two days of recovery should be allotted in studies involving multiple exposures to fatiguing protocols. Long lasting effects of fatigue could be present when shorter amounts of recovery period were assigned. A second study was also carried out to investigate the effects of work parameters (force-level, work-rest ratio, and work cycle) on muscular fatigue during intermittent static efforts. It was suggested that work conditions with muscular contraction level less than 12% MVE was non-fatiguing, irrespective of the values of the work parameters selected. Intermittent work with higher levels of muscle contraction might be acceptable, but it was dependent upon interactions of the other two parameters. The effects of dynamic work conditions on muscle fatigue were investigated in another study. Findings from this third study suggested that muscles responded differently under dynamic conditions and the use of typical EMG measures (dynamic EMG) could be less sensitive. This study further demonstrated that fatigue evaluations during such conditions were difficult, and only a limited number of EMG-based measures could be potentially employed. / Ph. D.