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Albertas Skurvydas and Marius Brazaitis

The aim of the study was to evaluate the effect of plyometric training (PT) on central and peripheral (muscle) fatigue in prepubertal girls and boys. The boys (n = 13, age 10.3 ± 0.3 years) and girls (n = 13, age, 10.2 ± 0.3 years) performed continuous 2-min maximal voluntary contractions (MVCs) before and after 16 high-intensity PT sessions. PT comprised two training sessions per week of 30 jumps in each session with 20 s between jumps. The greatest effect of PT was on excitation–contraction coupling, (twitch force increased by 323% in boys and 21% in girls) and height of a counter–movement jump (increased by 37% in boys and 38% in girls). In contrast, the quadriceps voluntary activation index, central activation ratio, and MVC did not change significantly after PT. The thickness of the quadriceps muscle increased by 9% in boys and 14% in girls after PT. In conclusion, boys and girls demonstrated similar changes in indicators of central fatigue (50–60% decrease) and peripheral fatigue (45–55% decrease) after MVC before and after PT.

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Michael J. Saunders

Endurance athletes commonly consume carbohydrate-electrolyte sports beverages during prolonged events. The benefits of this strategy are numerous—sports-beverage consumption during exercise can delay dehydration, maintain blood glucose levels, and potentially attenuate muscle glycogen depletion and central fatigue. Thus, it is generally agreed that carbohydrate-electrolyte beverages can improve endurance performance. A controversy has recently emerged regarding the potential role of protein in sports beverages. At least 3 recent studies have reported that carbohydrate-protein ingestion improves endurance performance to a greater extent than carbohydrate alone. In addition, carbohydrate-protein ingestion has been associated with reductions in markers of muscle damage and improved post exercise recovery. Although many of these muscle damage and recovery studies examined post exercise nutritional intake, recent evidence suggests that these benefits may be elicited with carbohydrate-protein consumption during exercise. These findings are intriguing and suggest that the importance of protein for endurance athletes has been underappreciated. However, 2 studies recently reported no differences in endurance performance between carbohydrate and carbohydrate-protein beverages. The varied outcomes may have been influenced by a number of methodological differences, including the amounts and types of carbohydrate or protein in the beverages, the exercise protocols, and the relative statistical power of the studies. In addition, although there are plausible mechanisms that could explain the ergogenic effects of carbohydrate-protein beverages, they remain relatively untested. This review examines the existing research regarding the efficacy of carbohydrate-protein consumption during endurance exercise. Limitations of the existing research are addressed, as well as potential areas for future study.

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Takeshi Kokubo, Yuta Komano, Ryohei Tsuji, Daisuke Fujiwara, Toshio Fujii and Osamu Kanauchi

(muscle exhaustion) and modification to the central nerve system (central fatigue; Clark & Mach, 2016 ). Several probiotics improve immune function and decrease URTI symptoms in healthy adults ( Berggren et al., 2011 ; de Vrese et al., 2005 ); however, their potency, although promising in athletes

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Romain Meeusen and Lieselot Decroix

, coordination, reaction time, and other cognitive tasks can be essential during several sports, including team sports. However, fatigue does not only occur at the peripheral level, but “centralfatigue or “mental” fatigue exist, involving brain mechanisms. Cognitive function plays an important role in athletic

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Sabrina Skorski, Iñigo Mujika, Laurent Bosquet, Romain Meeusen, Aaron J. Coutts and Tim Meyer

underlying mechanisms are not yet understood, it has been suggested that central fatigue might be related to a change in the synthesis and metabolism of brain monoamines, such as serotonin, dopamine, and noradrenaline. 25 These neurotransmitters play a key role in the modulation of various brain functions

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Alice M. Wallett, Amy L. Woods, Nathan Versey, Laura A. Garvican-Lewis, Marijke Welvaert and Kevin G. Thompson

fatigue. Stoter 29 has observed a modest reduction (∼2%) in voluntary activation (indicative of central fatigue) in quadriceps following 1500-m cycling TTs, whereas force developed following a 5-second potentiated twitch (indicating peripheral fatigue) was reduced appreciably (∼25%). It is plausible that

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Joseph B. Lesnak, Dillon T. Anderson, Brooke E. Farmer, Dimitrios Katsavelis and Terry L. Grindstaff

within 3 to 5 trials 19 and providing 2 minutes of rest between sets. Although the average number of trials was 5.5, the range was between 3 and 9 trials. Higher numbers of attempts (>6) may not allow accurate determination of a 1RM 19 and may also contribute to central fatigue. This variability in

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Stephen P. Bailey, Julie Hibbard, Darrin La Forge, Madison Mitchell, Bart Roelands, G. Keith Harris and Stephen Folger

described the role of altered corticomotor activity in the precipitation of central fatigue during cycling exercise. The relationship between corticomotor excitability and quadriceps muscle function has been previously described in various clinical populations including individuals recovering from anterior

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Guillaume P. Ducrocq, Thomas J. Hureau, Olivier Meste and Grégory M. Blain

mechanisms associated with exercise-induced neuromuscular fatigue involve the alterations of processes within the muscle (ie, peripheral fatigue) 24 and/or the central nervous system (ie, central fatigue). 25 Little is known on the time course of neuromuscular fatigue recovery following a high volume of

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Katherine Elizabeth Black, Alistair David Black and Dane Frances Baker

is a large cognitive aspect to rugby ( Roberts et al., 2008 ). For optimal decision making and skill execution, it is important that blood glucose levels are maintained ( Karelis et al., 2010 ). Therefore, carbohydrate ingestion may also attenuate central fatigue, that is, central drive for