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ABSTRACT: Matlák, J, Fridvalszki, M, Kóródi, V, Szamosszegi, G, Pólyán, E, Kovács, B, Kolozs, B, Langmár, G, and Rácz, L. Relationship between cognitive functions and agility performance in elite, young, male soccer players. J Strength Cond Res 38(1): 116-122, 2024-The aim of this study was to assess the relationship between agility performance and cognitive functions measured under laboratory conditions among elite young soccer players. Twenty-five, elite, young, male soccer players (12.3 ± 0.4 years, 155.4 ± 7.6 cm, 42.6 ± 6.9 kg) completed a battery of field tests, including 5-, 10-, 20-m sprints, change of direction speed (CODS), standing long jump, and an agility test based on a human stimulus. Subjects also completed choice reaction (RT, S3) and reactive stress tolerance (DT, S1) tests on the Vienna Test System. There was a moderate significant relationship (p < 0.05) found between mean reaction time and mean motor time during the choice reaction task and decision time in the agility test. Decision time also showed a large significant correlation (p < 0.05) with total time in the agility test. No significant correlation was found between total time in the agility test and variables measured during RT and DT tests. No significant correlations were found between agility test results and results from straight line sprints, CODS, and standing long jump tests. The results of this study suggest that choice reaction time is related to decision-making speed during the agility task used in this study and can have an indirect effect on agility performance in elite young soccer players. Further studies assessing the relationship between different cognitive functions and agility performance in different sports and age categories could help in the identification of determinant cognitive functions in perceptual and decision-making factors of agility.
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Rendimiento Atlético , Carrera , Fútbol , Humanos , Masculino , Cognición , Tiempo de ReacciónRESUMEN
Neurocognitive assessment tools have been proposed to optimize, maintain, and improve perceptual-cognitive performance. Here, we investigated the feasibility and efficacy of a novel neurofeedback system, neuroMoon (nM), on cognitive abilities compared with one of the most popular perceptual-cognitive training (PCT) tools both in sports and rehabilitation called NeuroTracker (NT). Thirty-one young athletes performed a comprehensive battery of cognitive tests from the Vienna Test System before and after a 12-session computer-based cognitive training program using nM (n = 11, age 22.6 ± 3.8 years), nM sham (CON, n = 10, age 20.3 ± 1.2 years) or NT (n = 10, age 20.5 ± 1.7 years) device. A series of repeated-measures ANOVA was performed to detect changes in cognitive abilities in response to the training. Participants had faster median reaction time in both the color-naming and word-reading conditions of the Stroop test (all p < 0.005), regardless of group. Regarding the task switching test, statistical analysis indicated faster working time and mean reaction time of the incongruent stimuli, repetition task, and shifting task (all p < 0.005), nevertheless, these changes were also regardless of group. In addition, we found fewer omitted (pre: 17.5 ± 8.3, post: 6.4 ± 1.5, d = 1.311) and more correct (pre: 261.6 ± 36.1, post: 278.6 ± 38.7, d = - 1.020) post-intervention answers in the determination test, regardless of group. Finally, participants in each group performed the digit span backward test with larger post (6.42 ± 1.54) vs. pre (5.55 ± 1.43) scores following the PCT (d = - 0.801). Overall, PCT with nM as compared with NT induced similar results in cognitive abilities suggesting its potential to be used to achieve and maintain better mental performance. However, considering that the sham stimulation also induced similar improvements in cognitive abilities, future studies should clearly determine the cognitive measures that could benefit from NF training.
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Neurorretroalimentación , Humanos , Adolescente , Adulto Joven , Adulto , Neurorretroalimentación/métodos , Proyectos Piloto , Estudios de Factibilidad , Cognición/fisiología , Tiempo de Reacción/fisiologíaRESUMEN
The purpose of this paper is to present the sensor placement strategies that currently determine the thermal monitoring of the phase conductors of high-voltage power lines. In addition to reviewing the international literature, a new sensor placement concept is presented based on a strategy centered on the following question: What are the chances of thermal overload if devices are only placed in certain tension sections? In this new concept, the number and installation location of the sensors are determined in three steps, and a new type of tension-section-ranking constant is introduced that is universal in space and time. The simulations based on this new concept show that the data-sampling frequency and the type of thermal constraint influence the number of sensors. The paper's main finding is that there are cases when only a distributed sensor placement strategy can result in safe and reliable operation. However, due to requiring a large number of sensors, this solution means additional expenses. In the last section, the paper presents different possibilities to reduce costs and introduces the concept of low-cost sensor applications. These devices can result in more flexible network operation and more reliable systems in the future.
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Curcumin (CCM) is one of the most frequently explored plant compounds with various biological actions such as antibacterial, antiviral, antifungal, antineoplastic, and antioxidant/anti-inflammatory properties. The laboratory data and clinical trials have demonstrated that the bioavailability and bioactivity of curcumin are influenced by the feature of the curcumin molecular complex types. Curcumin has a high capacity to form molecular complexes with proteins (such as whey proteins, bovine serum albumin, ß-lactoglobulin), carbohydrates, lipids, and natural compounds (e.g., resveratrol, piperine, quercetin). These complexes increase the bioactivity and bioavailability of curcumin. The current review provides these derivatization strategies for curcumin in terms of biological and physico-chemical aspects with a strong focus on different type of proteins, characterization methods, and thermodynamic features of protein-curcumin complexes, and with the aim of evaluating the best performances. The current literature review offers, taking into consideration various biological effects of the CCM, a whole approach for CCM-biomolecules interactions such as CCM-proteins, CCM-nanomaterials, and CCM-natural compounds regarding molecular strategies to improve the bioactivity as well as the bioavailability of curcumin in biological systems.
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Antineoplásicos , Curcumina , Curcumina/farmacología , Curcumina/química , Disponibilidad Biológica , Antioxidantes/farmacología , Antioxidantes/química , Resveratrol , Albúmina Sérica Bovina , Proteína de Suero de Leche , Quercetina , Antifúngicos , Antineoplásicos/farmacología , Lactoglobulinas/química , Lípidos , Antivirales , Carbohidratos , AntibacterianosRESUMEN
BACKGROUND: There is a need to develop strategies that could contribute to the physical and mental preparation of motorsport athletes. A common method used by experienced motorsport athlete physical trainers is flashing light devices to train or assess reactive agility, despite limited evidence. Therefore, in the present study, we determined the effects of a 6-week reactive agility training program using light-based stimuli on the physiological and cognitive abilities of car racing drivers. MATERIALS AND METHODS: The CONSORT guidelines for randomized controlled trial were used. In a single-blinded randomized controlled trial, 24 car racing drivers (EXP, n = 12; CON, n = 12) performed a comprehensive battery of cognitive tests marketed specifically at motorsport athletes from Vienna test system (VTS) at rest or during moderate intensity exercise on a bicycle. Physiological abilities were determined via a maximal incremental cardio-respiratory treadmill test. Baseline and post-intervention tests were performed on three consecutive days. Participants in EXP underwent a 6-week intervention consisting of 60-min training sessions twice a week using the Witty SEM light stimulus. RESULTS: Participants in EXP but not in CON performed some of the VTS cognitive tasks with higher accuracy and/or shorter reaction time after the intervention at rest and during exercise. Car racing drivers performed the STROOP word-reading condition more accurately when the task was performed during the exercise vs. rest, regardless of group. In addition, the intervention induced beneficial changes in peak heart rate (HR), HR at gas exchange threshold, ventilation, and relative maximal oxygen consumption (rVO2 max). In contrast, body mass and fat mass increased, while peak HR and rVO2 max decreased in CON. Finally, participants in EXP improved their reactive agility performance and reaction time throughout the training program. CONCLUSION: Overall, the reactive agility training program using light-based stimuli appeared to be efficient to induce beneficial effects on some physiological and cognitive performance measures; therefore, it may have the potential to contribute to car racing drivers' physical and mental performance.
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The aim of the study was to develop and assess the reliability of a functional agility test containing offensive elements for water polo players. Eighteen young male (15.3 ± 0.5 years, 178.3 ± 4.7 cm, 69.4 ± 10.0 kg) water polo players with a minimum of 5 years of sport-specific experience participated in this study. The test contained reactive high-intensity short-term swimming with changes in direction and manoeuvres after perceiving unknown stimuli given by tester players, and also included a shooting task at a goal, first from 7 m and then from 5 m. Execution time and shooting efficiency were measured by two experienced water polo coaches (Evaluators A and B). All statistical analyses were calculated using SPSS. The intrarater reliability between attempts showed good reliability for both evaluators (Evaluator A: ICC: 0.87; 95% CI: 0.66-0.95 and Evaluator B: ICC: 0.88; 95% CI: 0.68-0.96). Interrater reliability between Evaluators A and B was excellent at both attempts (Attempt 1: ICC: 0.97; 95% CI: 0.93-0.99 and Attempt 2: ICC: 0.98; 95% CI: 0.91-0.99). A lack of correlation between shooting performance from 7 m and 5 m distances and execution time was observed in the protocol. The test we presented in this study was found to be a reliable measurement tool for testing offensive agility performance based on open skill nature among water polo players.
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Rendimiento Atlético , Humanos , Masculino , Motivación , Reproducibilidad de los Resultados , Proyectos de Investigación , NataciónRESUMEN
Skeletal muscle status and its dynamic follow up are of particular importance in the management of several diseases where weight and muscle mass loss and, consequently, immobilization occurs, as in cancer and its treatment, as well as in neurodegenerative disorders. But immobilization is not the direct result of body and muscle mass loss, but rather the loss of the maximal tension capabilities of the skeletal muscle. Therefore, the development of a non-invasive and real-time method which can measure muscle tension capabilities in immobile patients is highly anticipated. Our aim was to introduce and evaluate a special ultrasound measurement technique to estimate a maximal muscle tension characteristic which can be used in medicine and also in sports diagnostics. Therefore, we determined the relationship between the results of shear wave elastography measurements and the dynamometric data of individuals. The measurements were concluded on the m. vastus lateralis. Twelve healthy elite athletes took part in our preliminary proof of principle study-five endurance (S) and seven strength (F) athletes showing unambiguously different muscle composition features, nine healthy subjects (H) without prior sports background, and four cancer patients in treatment for a stage 3 brain tumor (T). Results showed a high correlation between the maximal dynamometric isometric torque (Mmax) and mean elasticity value (E) for the non-athletes [(H + T), (r = 0.795)] and for the athletes [(S + F), (r = 0.79)]. For the athletes (S + F), the rate of tension development at contraction (RTDk) and E correlation was also determined (r = 0.84, p < 0.05). Our measurements showed significantly greater E values for the strength athletes with fast muscle fiber dominance than endurance athletes with slow muscle fiber dominance (p < 0.05). Our findings suggest that shear wave ultrasound elastography is a promising method for estimating maximal muscle tension and, also, the human skeletal muscle fiber ratio. These results warrant further investigations with a larger number of individuals, both in medicine and in sports science.
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Atletas/estadística & datos numéricos , Composición Corporal , Diagnóstico por Imagen de Elasticidad/métodos , Contracción Muscular , Fuerza Muscular , Músculo Esquelético/fisiología , Ultrasonografía/métodos , Adulto , Fenómenos Biomecánicos , Femenino , Humanos , Masculino , Músculo Esquelético/diagnóstico por imagen , Resistencia al Corte , Adulto JovenRESUMEN
The aim of the study was to assess the relationship between reactive agility and change of direction speed (CODS) among amateur soccer players using running tests with four directional changes. Sixteen amateur soccer players (24.1 ± 3.3 years; 72.4 ± 7.3 kg; 178.7 ± 6 cm) completed CODS and reactive agility tests with four changes of direction using the SpeedCourt™ system (Globalspeed GmbH, Hemsbach, Germany). Countermovement jump (CMJ) height and maximal foot tapping count (completed in 3 seconds) were also measured with the same device. In the reactive agility test, participants had to react to a series of light stimuli projected onto a screen. Total time was shorter in the CODS test than in the reactive agility test (p < 0.001). Nonsignificant correlations were found among variables measured in the CODS, reactive agility, and CMJ tests. Low common variance (r = 0.03-0.18) was found between CODS and reactive agility test variables. The results of this study underscore the importance of cognitive factors in reactive agility performance and suggest that specific methods may be required for training and testing reactive agility and CODS.
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Rendimiento Atlético/fisiología , Carrera/fisiología , Fútbol/fisiología , Adulto , Alemania , Humanos , MasculinoRESUMEN
To determine the acute task and stretch-load dependency of neuromuscular impairments after muscle-damaging exercises, we examined the magnitude of strength deficits in isometric and stretch-shortening cycle (SSC) contractions after a single bout of exercise. Ten trained men performed 90 unilateral isokinetic eccentric-concentric knee extensions on a dynamometer. Plasma creatine kinase activity, muscle soreness, maximal isometric torque, short-range stiffness, and peak torque in the eccentric phase of the SSC contraction at 3 stretch-loads (120, 150, and 180 J) were determined in the quadriceps before and 24 hours after exercise. During SSC, positive mechanical work and efficiency were also calculated. Creatine kinase and soreness increased at 24 hours (p < 0.05). In each of the 3 stretch-load conditions, muscle damage affected short-range stiffness less than isometric and peak SSC torque (p < 0.05), providing evidence for a selective impairment in contractile function after muscle damage. With greater SSC stretch-load peak, SSC torque deficit increased linearly, whereas short-range stiffness deficit was unaffected. Efficiency declined only at the 180-J condition (p < 0.05) as a result of decreased positive work (p < 0.05). It was concluded that intense exercise produced microtrauma in the muscle, and a selective loss of force generating capacity, which suggests greater damage to the contractile machinery. Practitioners may expect greater acute impairment of force generation in movements that use large loads in their daily training drills. However, altered knee flexion strategy during SSC may compensate for the force deficit, preserving mechanical efficiency at smaller stretch-loads.
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Contracción Isométrica/fisiología , Acondicionamiento Físico Humano/efectos adversos , Esfuerzo Físico/fisiología , Músculo Cuádriceps/fisiopatología , Adolescente , Adulto , Creatina Quinasa/sangre , Humanos , Masculino , Mialgia/etiología , Músculo Cuádriceps/patología , Torque , Adulto JovenRESUMEN
This study examined the effects of short-term eccentric-concentric knee extensor training on mechanical and biochemical variables, myoelectric activity, and muscle soreness. Seventeen men were assigned to either experimental (E, n = 10) or control group (C, n = 7). Group E performed 90 maximal isokinetic eccentric-concentric knee extensor contractions on each of 3 consecutive days (Tr1-Tr3) followed by 1-day rest, and then on 4 more consecutive days (Tr4-Tr7). Peak eccentric torque of each contraction during the training was recorded and averaged for each session (MTr). Maximal isometric torque (M0), eccentric torque (M(ecc)), integrated electromyography (iEMG), plasma creatine kinase (CK), and lactate dehydrogenase (LDH) activities were measured before, immediately, 24, 48, and 72 hours after Tr1, at 1 and 3 days after Tr7. Group C did not train but performed all exercise tests; CK and LDH were measured at 3 time points only. Acutely, M0 and M(ecc) decreased and CK, LDH, and soreness increased more in E than in C 24 hours after Tr1. Chronically, MTr and M0 increased more in E than C by Tr7 and CK, LDH, and muscle soreness gradually decreased by Tr7 whereas iEMG increased more in E than in C after Tr3 through Tr7. High-intensity short-term eccentric-concentric knee extensor exercise training produced immediate reductions in maximal voluntary force. Most likely neural adaptations contributed to rapid recovery and strength adaptations because maximal voluntary force increased by the end of the training protocol in previously trained healthy adults.
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Ejercicio Físico , Rodilla/fisiología , Adolescente , Adulto , Creatina Quinasa/sangre , Electromiografía , Humanos , Masculino , Contracción Muscular/fisiología , Músculo Esquelético/fisiología , Dolor/enzimología , Dolor/etiología , Torque , Adulto JovenRESUMEN
Evidence indicates that repeated-bouts of eccentric exercise (EE) do not exacerbate the extent of muscle damage indices, as compared to a single-bout. We hypothesized that molecular adaptations, under repeated-bouts of EE, would include suppression of muscle repair inhibitory factors such as myostatin and up-regulation of muscle repair positive regulatory factors such as myogenic regulatory factors (MRFs). Fifteen males were recruited for this study. The exercise group (n=9) successfully completed six sets of 15 reps of maximum voluntary eccentric contractions, for six consecutive days, using a dynamometer (Multicont-II). Blood and muscle biopsy samples were obtained from each subject 1 week prior to exercise, 2 days post the first training session, and 24 h after the last training session. Gene expression levels were determined using real-time RT-PCR. Blood samples were analyzed for creatine kinase (CK) and lactate-dehydrogenase (LDH) activity. Repeated-bouts of EE induced a large down-regulation of myostatin mRNA (-73%) which persisted throughout the study. The responses of MRFs were mild. At day 3 only myogenin increased significantly (1.9 fold) while MyoD decreased by 45%. Surprisingly, at day 7, despite the presence of muscle damage indices, all MRFs returned to the pre-exercise levels. The results of the present study showed that repeated-bouts of EE, for six consecutive days, dramatically decreased Myostatin mRNA expression but impaired the expression patterns of MRFs such that, with the exception of myogenin that showed a moderate non-sustained increase, MyoD and MYf5 response was minimal.
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Ejercicio Físico/fisiología , Expresión Génica/fisiología , Factores Reguladores Miogénicos/biosíntesis , Factores Reguladores Miogénicos/genética , Factor de Crecimiento Transformador beta/biosíntesis , Adulto , Diferenciación Celular/fisiología , Proliferación Celular , Creatina Quinasa/metabolismo , ADN Complementario/biosíntesis , ADN Complementario/genética , Humanos , Antígeno Ki-67/metabolismo , L-Lactato Deshidrogenasa/metabolismo , Masculino , Contracción Muscular/fisiología , Fuerza Muscular/fisiología , Músculo Esquelético/metabolismo , Músculo Esquelético/fisiología , Proteína MioD/biosíntesis , Proteína MioD/genética , Factor 5 Regulador Miogénico/biosíntesis , Factor 5 Regulador Miogénico/genética , Miostatina , ARN Mensajero/biosíntesis , ARN Mensajero/genética , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Regulación hacia Arriba/fisiología , Quinasas p21 Activadas/biosíntesis , Quinasas p21 Activadas/genéticaRESUMEN
We hypothesized that the history of contraction would affect the in vivo quadriceps torque-velocity relationship. We examined the quadriceps torque-velocity relationship of the human knee extensors at the descending and ascending limb of the torque-position relationship by initiating the knee extension at a knee angle position of 1.39 rad (80 degrees ) or 0.87 rad (50 degrees ) over a 0.52 rad (30 degrees ) range of motion under conditions of constant or linearly increasing velocity. Maximal voluntary isometric knee extension torque (M(0)) was measured at 1.87 rad, 0.87 rad, and 0.35 rad, and concentric torque was measured. The subjects carried out ten maximal knee extensions at ten distinct velocities, each velocity ranging between 0.52 rad x s(-1) to 5.24 rad x s(-1) in steps of 0.52 rad x s(-1). Peak concentric torque was measured and mean torque calculated from the respective torque-time curves. Peak or mean torque, computed from the individual torque-time curves, and velocity data were fitted to the Hill equation under the four experimental conditions and the curve parameters computed. The M(0) was similar at 0.87 rad and 1.39 rad, but it was significantly lower at 0.35 rad. In the low-velocity domain of the torque-velocity curve where a plateau normally occurs, peak torque was always lower than M(0). Peak and mean torque were significantly greater under linearly increasing velocity conditions and the 1.39 rad starting knee position. Mean torque but not peak torque data could be well fitted to the Hill equation and the two computations resulted in significantly different Hill curve parameters including the concavity ratio, peak power, and maximal angular velocity. We concluded that the history of contraction significantly modifies the in vivo torque-velocity relationship of the human quadriceps muscle. Muscle mechanics and not neural factors may have accounted for the inconsistencies in the human torque-velocity relationships reported previously.