Programa de Pós-Graduação em Ciências do Movimento Humano - PPGCMH/ICS
URI Permanente desta comunidadehttps://repositorio.ufpa.br/handle/2011/15816
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Navegando Programa de Pós-Graduação em Ciências do Movimento Humano - PPGCMH/ICS por Orientadores "PENNA, Eduardo Macedo"
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Item Acesso aberto (Open Access) Efeito da suplementação aguda de guaraná (Paullinia Cupana) e de uma dose equivalente de cafeína sobre parâmetros de potência muscular na execução do exercício supino reto(Universidade Federal do Pará, 2024) COLAÇO, Fernando Sampaio; PENNA, Eduardo Macedo; http://lattes.cnpq.br/3746450308327976; https://orcid.org/0000-0003-0058-7967Introduction: Guarana (Paullinia Cupana) is a natural substance rich in caffeine and other bioactive components. It is known that its acute ingestion can improve cognitive performance and effort perception parameters, but it is still unclear whether this ingestion can be efficient as an ergogenic substance in the production of muscular power, and whether this possible ergogenic effect is due to its caffeine concentration Objective: The objective of the present research was to compare the effect of acute ingestion of Guaraná (Paullinia Cupana) with an equivalent dose of caffeine on muscle power parameters. Methods: 34 individuals (18 to 35 years old) practicing resistance training were recruited and randomized into three experimental situations: PLACEBO (PLA); 500mg of guarana (GUA-500, containing 130mg of caffeine) and 130mg of caffeine (CAF-130). The individuals underwent a familiarization session with the bench press exercise performed on the Smith machine, in which the individuals' 1RM value and the optimal load for power production were measured. After a minimum interval of 48 hours from the 1RM test and optimal load, the individuals performed, on different days, the three experimental sessions in a randomized order: acute ingestion of caffeine, placebo or Guarana. Each experimental situation had a minimum washout interval of two days. A percentage of optimal load for power production was estimated through a progressive test on the bench press using only the bar, 30%, 40%, 50% and 60% of 1RM in order to identify the best load to perform 3 sets up to 40% of the loss of movement speed, with a 5-minute break between sets. Before performing the physical task, the individuals performed two sets of five repetitions using the load identified as optimal, with a 3-minute break between each set. warm-up series. Participants performed the concentric phase of movement performed at maximum intentional speed, and the eccentric phase lasting 2 seconds, in which the following variables were measured: average power (Watts), peak power (Watts), peak speed (m/s), and average propulsive speed (m/s). Results: Regarding the number of repetitions achieved between the experimental situations, no statistically significant difference was identified between the factors capsule ingested (F(2, 264) = 1.4689, P = 0.2320; partial η² = 0.01); between the three series performed (F(2, 264 = 0.5775, P = 0.5620) and in relation to Capsule: Series (F = 0.2937, P = 0.8819), in relation to Peak Power, the analyzes did not detect any significant effect on the values Capsule (F (2,264) = 0.0908; P = 0.7479), Series (F (2, 264) = 1.5053; P = 0.2238) and for the interactions Capsule: Series (F (4, 264) = 0.7674; P = 0.5453), regarding Average Power, the analysis did not detect significant effects for the Capsule factors (F (2, 264) = 0.028; P = 0.972; partial η² < 0.01), Series (F (2, 264) = 1.187; P = 0.306; partial η² < 0.01), and for the Capsule interaction: series (F (4,264) = 1.266; P = 0.283; partial η² = 0.02), as for Peak Speed, the analysis indicated no effect for the Capsule factor (F (2,263) = 1.162; P = 0.314; partial η² < 0.01), a significant effect for the factor Series (F (2, 263) = 3, 479; P = 0.03; partial η² = 0.03), in the Capsule:series interaction analysis (F (4, 263) = 1, 337; P = 0.256 ; partial η² = 0.02), no significant effect was identified. With regard to Average propulsive speed, no significant differences were identified for the factors Capsule (F (2, 264) = 0.401; P = 0.669; partial η² = 0.01), Series (F (2,264) = 1 , 327; P = 0.266; partial η² < 0.01) and for the Capsule: series interaction (F (4, 264) = 1.199; P = 0.311; partial η² < 0.01). Conclusion: Supplementation with 500mg of Guarana containing 130mg and 130mg of caffeine alone did not trigger any ergogenic effect on muscle power parameters and bench press speed.Item Acesso aberto (Open Access) Os efeitos do treinamento pliométrico sobre o desempenho do tempo de resposta em praticantes de esportes de combate de percussão(Universidade Federal do Pará, 2025-02-12) MACHADO, Hugo Enrico Souza; PENNA, Eduardo Macedo; http://lattes.cnpq.br/3746450308327976; https://orcid.org/0000-0003-0058-7967Reaction time is an important variable in combat sports, as it depends on both central mechanisms (perception and information processing) and peripheral mechanisms (movement execution). Additionally, the ability to maximize force production in the shortest possible time can enhance muscle contraction speed and make strikes faster. However, little is known about the effects of power training adaptations on overall reaction time performance in combat sports practitioners. Thus, this study aimed to investigate the effects of six weeks of plyometric training on the performance of simple and choice reaction times (SRT and CRT, respectively) in striking combat sports athletes. For this purpose, 16 volunteers were divided into two groups: traditional training group (TTG = 8) and TTG + plyometric training group (TTG+PLYO = 8). Participants were assessed at two time points (pre- and post-intervention) for SRT and CRT in specific semicircular kick tasks, as well as for countermovement jump (CMJ), squat jump (SJ), horizontal jump (HJ), and reactive strength index (RSI). The TTG+PLYO group followed a six-week plyometric training (PT) program, training twice a week in addition to their regular sport-specific training. In contrast, the TTG group continued with their regular training only. For statistical analysis, a two-way ANOVA (group × time) and an independent t-test were used to evaluate the percentage of variation between groups. A significance level of p < 0.05 was adopted. Results showed no significant group × time interaction for SRT (F = 0.73; p = 0.40; η2 = 0.003) or CRT (F = 0.04; p = 0.83; η2 = 0.001). Regarding jump performance, only SJ presented a significant group × time interaction (F = 6.16, p = 0.026, η2 = 0.01), with an increase in jump height observed only in the TTG+PLYO group (pre = 30.3 ± 5.7 cm, post = 33.4 ± 5.8 cm, p = 0.01) and a significant difference in percentage variation (TTG: 0.4 ± 4.8%; TTG+PLYO: 9.1 ± 8.1%; p = 0.02). Additionally, RSI showed a significant variation only for the TTG+PLYO group (TTG = -2.3 ± 8.3%; TTG+PLYO = 24.4 ± 31.4%; p = 0.03). We conclude that six weeks of PT improved the physical performance related to power production in the TTG+PLYO group, without significant improvements in overall specific reaction time performance in combat sports practitioners.Item Acesso aberto (Open Access) A fadiga mental altera a percepção subjetiva de esforço, mas não prejudica o tempo de resposta de árbitros de futebol durante uma tarefa física simulada(Universidade Federal do Pará, 2023-04-27) LIMA, Cássio Zacarias Lopes de; PENNA, Eduardo Macedo; http://lattes.cnpq.br/3746450308327976; https://orcid.org/0000-0003-0058-7967Mental fatigue (MF) is a psychobiological state caused by prolonged and demanding cognitive activity, characterized by feelings of tiredness and lack of energy induced by periods of demanding cognitive activity. MF negatively affects decision-making in sports, as these effects have been associated with a reduction in the performance of executive functions, which are conceptualized as a set of cognitive processes used to plan and carry out actions to achieve a goal. In this context, it is known that the performance of executive functions has been strongly associated with the decision-making of soccer referees, so understanding whether MF reduces the cognitive performance of referees is relevant. Thus, the aim of this study was to investigate the effects of mental fatigue and simulated physical task on soccer referees, on response time in a test that evaluates executive functions, and subjective perception of effort. Twelve professional regional soccer referees participated in the study, and made three visits to the laboratory, the first visit for evaluations and familiarization with the experimental protocols, and signing of the Informed Consent Form (ICF). In the 2nd and 3rd visits, the participants were exposed to two experimental conditions, mental fatigue or control, in a cross-over and randomized way. Therefore, in the MF condition, referees performed the Stroop Test and in the control condition, they watched an emotionally neutral video, and after these conditions, they were required to perform executive function tests simultaneously with the simulated physical task for soccer referees. The results revealed that there was no effect of mental fatigue on the performance of executive functions (P = 0.395). However, higher perceptions of effort were found in the mental fatigue condition (P = 0.018). In this sense, the present study shows that although mental fatigue alters the subjective perception of effort, there was no impairment in the executive functions performance of soccer referees.