Acute Specific Effects of Caffeine-containing Energy Drink on Different Physical Performances in Resistance-trained Men

International Journal of Exercise Science 11(4): 260-268, 2018. Caffeine containing energy drink (ED) is frequently used as ergogenic aid, but its effect on performance need more investigation. Thus, the aim of this study was to analyze the effects of acute ingestion of an ED on the physical performance of resistance-trained men subjected to successive tests in the same experimental protocol. Fifteen resistance-trained males (21.0 ± 0.3 yrs; 177.4 ± 1.8 cm; 79.6 ± 1.8 kg) ingested 2.5 mg caffeine per kg of body weight (619.5 ± 14.6 mL of ED) or a placebo in a double-blind randomized cross-over design. Physical performance was randomized for the maximum repetition tests (80% 1RM) in the bench press exercise and unilateral knee extension (dominant leg), maximal isometric hand-grip test in both hands, standing long jump and repeated sprint ability test. The paired Student-t test showed that ED intake increased performance compared to the placebo for the number of repetitions in the unilateral knee extension test of the dominant leg (11.5 ± 0.9 reps vs 9.5 ± 0.8 reps; P = 0.001) and bench press (10.2 ± 0.4 reps vs 8.1 ± 0.5 reps; P = 0.01); and also increased isometric strength in the hand-grip maximal test in the right (53.7 ± 1.5 kg vs. 47.7 ± 1.6 kg; P = 0.02) and left hand (52.9 ± 1.5 kg vs. 45.9 ± 1.3 kg; P = 0.02). In conclusion, acute ingestion of ED increased performance only in specific strength tests in resistance-trained men

Competition, research and extension: the three approaches to the popularization of small satellites in the Alto Paraopeba region in Brazil

There are several approaches to the diffusion of the space technologies, three of them are in this work: competition, research, and extension. Thus, the objective of this work is to focus on presenting the results of the Brazilian nanosatellite team called NoizOrbita, and also to qualify quantitatively the impact of using these approaches in popularizing the topic of small satellites for space educational purposes. The team was founded on September 29, 2020, by three people: an alumni of Telecommunications Engineering at Federal University of São João del- Rei (UFSJ), Alto Paraopeba Campus (CAP), currently pursuing his Ph.D. in CubeSat Antennas at UFSC; a student currently in the 6th period of the Telecommunications Engineering undergraduate course (class of 2019); and a professor in the Department of Telecommunications and Mechatronics Engineering (DETEM). This initiative is intended to be a gateway to the space/satellite technologies in the institution and is based on three main pillars: Competitions, Research, and Extension in Nanosatellites. The team aims to obtain and develop small satellite technologies involving CAP undergraduate and graduate students, which enables them to learn the concepts of Space Engineering with the methodology of "learning by doing", covering the entire lifecycle of a spacecraft, even in a less complex way, through Systems Engineering approach. It also encourages the students to carry out scientific studies, prepare and publish papers, participate in conferences, and through extension, spread all the knowledge acquired in the various layers of society in the Alto Paraopeba region. Team members are all undergraduate and graduate students. Considering that one of the main characteristics of the team is its multidisciplinary nature, it leads to the advantage that students from all courses offered at CAP can join the group. This is reflected a lot by the concept of satellite engineering, since professionals from various areas of knowledge are sought for working with satellites and small satellites. Thus, in this work the main numbers related to the team were gathered, collected and presented in order to assess the impact and/or reach of the activities in its first year of existence. Data were extracted from databases, histories, and records on the various knowledge and information dissemination platforms. Regarding the research approach, the team obtained a significant number of scientific productions; regarding extension, presentations with satellite subjects were performed; and a great achievement with the competition aspect was obtained, which shows the effectiveness of these three approaches

Cardiovascular and autonomic responses after exercise sessions with different intensities and durations

BACKGROUND: Several studies have reported the phenomenon of post-exercise hypotension. However, the factors that cause this drop in blood pressure after a single exercise session are still unknown. OBJECTIVE: To investigate the effects of aerobic exercise on the acute blood pressure response and to investigate the indicators of autonomic activity after exercise. METHODS: Ten male subjects (aged 25 ± 1 years) underwent four experimental exercise sessions and a control session on a cycle ergometer. The blood pressure and heart rate variability of each subject were measured at rest and at 60 min after the end of the sessions. RESULTS: Post-exercise hypotension was not observed in any experimental sessions (P > 0.05). The index of parasympathetic neural activity, the RMSSD, only remained lower than that during the pre-exercise session after the high-intensity session (&#916; = -19 ± 3.7 for 15-20 min post-exercise). In addition, this value varied significantly (P < 0.05) between the high- and low-intensity sessions (&#916; = -30.7 ± 4.0 for the high intensity session, and &#916; = -9.9 ± 2.5 for the low intensity session). CONCLUSION: The present study did not find a reduction in blood pressure after exercise in normotensive, physically active young adults. However, the measurements of the indicators of autonomic neural activity revealed that in exercise of greater intensity the parasympathetic recovery tends to be slower and that sympathetic withdrawal can apparently compensate for this delay in recovery

Acute Effect of Caffeine Intake on Hemodynamics after Resistance Exercise in Young Non-hypertensive Subjects

This study aimed to examine the effect of caffeine on hemodynamics after a resistance exercise session. Fifteen subjects completed two randomly ordered experimental resistance exercise sessions 45 min after the ingestion of either caffeine (4 mg.kg-1) or placebo. Systolic (SBP), diastolic (DBP) and mean (MAP) blood pressures were measured before consuming caffeine; SBP, DBP, MAP, heart rate, stroke volume, cardiac output and peripheral vascular resistance (PVR) were measured immediately before and after each of the sessions; SBP, DBP and MAP were measured for 9 hours after sessions. Caffeine increased (p \u3c 0.05) pre-exercise DBP and MAP. In caffeine and placebo conditions significant decreases (p \u3c 0.05) were noted in SBP, MAP, and PVR between the pre- and post-exercise time points. Notwithstanding, the mean values for SBP, DBP and MAP during the 9 h of post-exercise monitoring were increased (p \u3c 0.05) for the caffeine. In conclusion, the cardiovascular effects of caffeine are different over the post-exercise period after resistance exercise in normotensive young adults

Relação entre o sistema renina angiotensina e as respostas cardiovasculares promovidas pelo exercício físico

Introduction and Objective: The renin angiotensin system (RAS) has an important function in the homeostasis of cardiovascular system, and the activation of the classical pathway results in the formation of angiotensin II which lead to increased blood pressure (BP). Whereas exercice interferes in cardiovascular responses to angiotensin II and consequently reduces the BP. Whereas exercice interferes in cardiovascular responses, this study aimed to review the literature regarding the possible relationship of physical training with the RAS.Methods: The work was divided into sessions of studies involving animals and studies involving humans. Searches were performed in Medline database, and the main criteria were samples with animals ou humans and articles published in English. After applied the inclusion and exclusion criteria, we selected 12 articles involving animals and 8 involving humans.Results: The studies involving animals and humans have shown that there is a relationship between physical training and RAS, and  cardiovascular responses observed after exercice may have some relationship with the RAS. Furthermore, studies in humans have shown that polymorphisms in some genes of the RAS may also be crucial to the cardiovascular responses found after exercice. Conclusion: Given the recent research linking cardiovascular responses after exercice with the SRA, this relationship seems to be important to consider the mechanism responsible for promoting certain cardiovascular responses after exercise, such as hypotension.Introdução e objetivos: O sistema renina angiotensina (SRA) apresenta importante função na homeostase do sistema cardiovascular, e a ativação da via clássica resulta na formação de angiotensina II, que leva ao aumento da pressão arterial (PA). No entanto, novos estudos tem evidenciado a ativação da via da angiotensina (1-7), a qual apresenta respostas contrárias a Angiotensina II e consequentemente reduz a PA. Considerando que o exercício físico interfere nas repostas cardiovasculares, este estudo teve o propósito de revisar a literatura quanto a possível relação do treinamento físico com o SRA.Métodos: o trabalho foi dividido em sessões de estudos que envolveram animais e estudos com seres humanos. A busca destes estudos foi realizada na base Medline e os principais critérios foram amostras com animais ou seres humanos e artigos publicados em inglês. Depois de aplicados os critérios de inclusão e exclusão, foram encontrados 12 artigos envolvendo animais e oito envolvendo seres humanos.Resultados: Os estudos demonstraram que existe uma relação entre o treinamento físico e o SRA, sendo que as respostas cardiovasculares observadas após o exercício físico pode apresentar alguma relação com o SRA. Além disso, estudos com seres humanos demonstraram que polimorfismos em alguns genes do SRA podem ser determinantes para as respostas cardiovasculares encontradas após o exercício físico. Considerações finais: Tendo em vista as recentes investigações que relacionam as respostas cardiovasculares após o exercício físico com o SRA, esta relaçação parece ser importante ao considerar os mecanismos responsáveis por promover determinadas respostas cardiovasculares após o exercício físico como a hipotensão.

Stimulus Expectancy and Stimulus Response of Caffeine on 4-Km Running Performance: a Randomized, Double-Blind, Placebo-Controlled and Crossover Study

International Journal of Exercise Science 15(2): 645-654, 2022. The placebo effect of caffeine has been poorly investigated in endurance exercise. Therefore, the aim of this study was to analyze the placebo effect of caffeine on 4 km running performance in amateur runners. Twenty-two healthy and recreational male runners (25.5 ± 8.4 yrs; 75.0 ± 7.1 kg; 173.7 ± 6.3 cm) underwent a deceptive experimental design consisting of three different sessions: a) control (CON) in which participants did not ingest any substance; b) placebo (PLA) in which participants ingested a capsule filled with maltodextrin but they were informed that they would receive caffeine; c) caffeine (CAF) in which participants were informed that they would receive caffeine and actually received caffeine. After 60 min for substances absorption, participants performed a 4-km test and they completed the distance as fast as possible. The time employed to cover the distance was lower in PLA (17.4 ± 1.5 min) and CAF (17.4 ± 1.4 min) than CON sessions (18.6 ± 2.8 min; P\u3c0.05). There were no differences in the 4-km times between PLA and CAF (P\u3e0.05) and no differences were reported between treatments for RPE (P\u3e0.05). In conclusion, there was a placebo effect of caffeine on a 4-km maximal running trial which entailed that believing to have ingested caffeine improved performance to a similar extent than actually receiving caffeine. Therefore, the expectancy induced by caffeine may be one of the mechanisms behinds the ergogenic effect of this stimulant on endurance exercise

Effect of Different Resistance Exercise Methods on Post-Exercise Blood Pressure

The aim of the present study was to evaluate the post-exercise blood pressure (BP) responses to two different methods of resistance exercise (RE, traditional multiple set and tri-set). Young adult men (n = 30, 19.6 &#; 0.7 years old; 76.0 ± 2.7 kg; 178.2 ± 6.7 cm; 90.5 ± 5.8 MBP) with six months of previous experience in RE were selected. The volunteers were randomly assigned into three groups (n = 10, each group): non-exercised control group (CON); multiple set group (MS); and a tri-set group (TRI). The TRI group performed three consecutive exercises (3 sets of 10 repetitions with 70% of 1RM and 1 minute of rest interval after the three exercises for the same muscle group) in the following order: bench press, cross-over and peck-deck and lat pull-down, seated cable row and barbell row. The multiple set group performed 3 sets of 10 repetitions for the same exercises, but with 1 minute rest interval between each set and exercise. After the exercise sessions and control situation, individuals remained seated for BP measure every 5 minutes up to 90 minutes. The repeated measures analysis of variance (ANOVA) (2 groups by three time points) was used, followed by post-hoc Bonferroni test, for p≤0.05. There were no significant alterations for systolic and diastolic blood pressure compared with the CON group and in the moments after exercise. Heart rate was increased after exercise for both exercised groups in all post-exercise measures compared with baseline. RE method (MS or TRI) exerted no influence on post-exercise blood pressure. Post-exercise induced hypotension may require the recruitment of larger muscle groups, such as those of the lower limbs

A comparison between overweight cutoff points for detection of high blood pressure in adolescents

OBJETIVOS: Avaliar a acurácia de três pontos de corte na determinação da pressão arterial elevada em adolescentes, dada a forte relação entre o excesso de peso e valores elevados de pressão arterial. MÉTODOS: Participaram do estudo 1.021 adolescentes de ambos os sexos, selecionados de maneira aleatória nas escolas públicas e particulares de Londrina (PR). O peso corporal foi aferido por meio de balança digital, e a estatura, por um estadi&#244;metro portátil com extensão máxima de 2 metros. A pressão arterial foi avaliada através de um aparelho automático. A capacidade do índice de massa corporal de detectar a pressão arterial elevada foi averiguada por meio da curva ROC e seus parâmetros (sensibilidade, especificidade e área sob a curva). RESULTADOS: Os pontos de corte da proposta nacional apresentaram maior acurácia (masculino: 0,636±0,038; feminino: 0,585±0,043) quando comparados aos pontos de corte das propostas internacional (masculino: 0,594±0,040; feminino: 0,570±0,044) e norte-americana (masculino: 0,612±0,039; feminino: 0,578±0,044). CONCLUSÃO: A proposta nacional foi a que apresentou melhor acurácia na indicação de valores elevados de pressão arterial.OBJECTIVES: To evaluate the accuracy of three different cutoff points for the detection of high blood pressure in adolescents, given the strong relationship between overweight and high blood pressure levels. METHODS: A total of 1,021 adolescents of both sexes were enrolled in the study, selected at random from public and private schools in Londrina, Brazil. Their body weight was measured using a digital balance, and their height with a portable stadiometer with a maximum extension of 2 meters. Arterial blood pressure was measured using an automatic apparatus. The capacity of body mass index to detect high blood pressure was gauged using ROC curves and their parameters (sensitivity, specificity, and area under the curve). RESULTS: The cutoff points proposed in a Brazilian standard exhibited greater accuracy (males: 0.636±0.038; females: 0.585±0.043) than the cutoff points proposed in an international (males: 0.594±0.040; females: 0.570±0.044) and a North-American standard (males: 0.612±0.039; females: 0.578±0.044). CONCLUSIONS: The Brazilian proposal offered greatest accuracy for indicating high blood pressure levels