João Paulo Borin

Efeitos do treinamento de resistência de força com alto número de repetições no consumo máximo de oxigênio e limiar ventilatório de mulheres

The effects of strength training on womens cardiorespiratory capacity have not been widely established. The purpose of this study was to investigate the effects of resistance strength training with high number of repetitions on maximum oxygen uptake and ventilatory threshold in young women during 12 weeks. Twenty women, aged 21.2 + 2.7 years, were included in the study and assigned to two groups: I - resistance strength training with high number of repetitions group (TG, n = 10), and II - control group (CG, n = 10). All volunteers were submitted to the following protocol: anthropometry, cardiopulmonary testing on treadmill and 1 RM tests in the following exercises: leg-press 45o, seated leg extension, hamstring curl, bench press, lat pull-down, military press, standing barbell curls and lying barbell extension. The tests were performed before and after 12 weeks of training. Along the proposed period, the groups performed: I -TG: resistance exercises, the same of 1 RM tests, with three series of 25 repetitions, almost 30% of 1 RM; II - CG: no physical training whatsoever. CG did not show changes in the studied variables (p 0.05) after 12 weeks. It is concluded that the resistance strength training with high number of repetitions improved the aerobic power of volunteers, evidenced by the increase of maximum oxygen uptake. However, the ventilatory threshold did not change.

Immune parameters, symptoms of upper respiratory tract infections, and training-load indicators in volleyball athletes

Background The control of immunological alterations becomes important during in-season training, as a result of increased incidence of infectious diseases, and may assist in avoiding interruptions to training due to illness. Objective The aim of the present study was to evaluate 28 weeks of chronic immune modulations in female volleyball athletes. Methods The sample was composed of twelve athletes aged 19.47 ± 2.49 years, height 1.78 ± 0.08 cm, and body mass 66.77 ± 7.8 kg. Leukocytes, individual immune cell count, interleukin (IL)-2, IL-6, and tumor necrosis factor (TNF)-α plasma cytokines were measured during the competitive period. Results Results revealed that immune variables were correlated with symptoms of upper respiratory tract infections and training-load indicators, indicating a possible marker of immune status. There was a statistically significant increase in total leukocytes, neutrophils, and monocyte count, a decrease in lymphocytes, and an increase in upper respiratory tract infection symptoms, with no change in IL-2, IL-6, and TNF-α. Correlations between subjective levels of tiredness, total leukocyte count, and neutrophils with upper respiratory tract infection symptoms were observed. Conclusion In conclusion, these correlations can represent important tools to access the immune status of an athlete during long training periods, preventing a possible immunosuppressive status.

The Effect Of Local Muscle Endurance Training on Cardiorespiratory Capacity in Young Women

Cesar, MC, Borin, JP, Gonelli, PRG, Simões, RA, Souza, TMF, and Montebelo, MIL. The effect of local muscle endurance training on cardiorespiratory capacity in young women. J Strength Cond Res 23(6): 1637-1643, 2009-The purpose of this study was to investigate the effect of local muscle endurance training on maximal oxygen uptake and ventilatory threshold in young women. Nineteen untrained women, ranging in age from 18 to 26 years, were included in the study and assigned to two groups: the control group (n = 10), and the resistance training group (n = 9). The following variables were obtained at baseline and after 12 weeks: body mass; maximal oxygen uptake, maximal heart rate, maximal oxygen pulse, oxygen uptake at the ventilatory threshold, heart rate at the ventilatory threshold, and oxygen pulse at the ventilatory threshold assessed by cardiopulmonary exercise testing on treadmill; 1-repetition maximum (RM) tests in bench press, latissimus pull down, military press, lying barbell extension, standing barbell curls, leg press, knee extension, and hamstring curl. The training group underwent resistance strength training. Loading during training followed the concept of maximum repetitions. Each session was defined as the performance of three sets of 15RM with a 60-second rest between sets and exercises. No significant changes were observed in the control group before and after 12 weeks (p > 0.05). All 1RM tests increased after training (p ≤ 0.01) in the training group, but no significant change was observed in body mass (p > 0.05). Cardiopulmonary variables showed no significant differences before and after resistance training (p > 0.05). These findings indicate that the local muscle endurance training realized produces no improvement in cardiorespiratory capacity in young women.

Genetic aspects of athletic performance: the African runners phenomenon

The current dominance of African runners in long-distance running is an intriguing phenomenon that highlights the close relationship between genetics and physical performance. Many factors in the interesting interaction between genotype and phenotype (eg, high cardiorespiratory fitness, higher hemoglobin concentration, good metabolic efficiency, muscle fiber composition, enzyme profile, diet, altitude training, and psychological aspects) have been proposed in the attempt to explain the extraordinary success of these runners. Increasing evidence shows that genetics may be a determining factor in physical and athletic performance. But, could this also be true for African long-distance runners? Based on this question, this brief review proposed the role of genetic factors (mitochondrial deoxyribonucleic acid, the Y chromosome, and the angiotensin-converting enzyme and the alpha-actinin-3 genes) in the amazing athletic performance observed in African runners, especially the Kenyans and Ethiopians, despite their environmental constraints.

Descriptive epidemiology of injuries in a Brazilian premier league soccer team

Soccer, which has a large number of participants, has a high injury incidence that causes both financial and time burdens. Therefore, knowledge about the epidemiology of soccer injuries could allow sports-medicine professionals, such as physicians and physiotherapists, to direct their work in specific preventive programs. Thus, our aim was to conduct an epidemiological survey of injuries sustained by professional soccer players from the same team who participated in the Brazilian championship premier league in 2009. To this end, we evaluated retrospectively player medical records from the team, which included name, date of birth, position, date of injury, mechanism of injury, and type of injury. In the period of study, 95 injuries were recorded: 42 (44.2%) were recorded during matches, and 53 (55.8%) during the training period. Injuries occurred more frequently in midfielders and strikers. All injuries happened in the lower limb, most of the injuries were muscular, and most occurred as the result of collisions with other athletes. In summary, this study demonstrates that there is a need for greater safety awareness in the training environment.

The distances covered by basketball referees in a match increase throughout the competition phases, with no change in physiological demand.

Background It is crucial to know the demands on basketball referees, in different match periods (MPs) and phases of competition, for planning referee training and subsequent successful refereeing. Objective To measure and evaluate the distance covered by referees in a match by measuring the number of interruptions, percentage of heart rate (%HR), and blood lactate concentration ([lac]) in different phases of competition and in different MPs. Method We studied the qualifying (QP), semifinal (SP), and final (FP) phases of a total of 12 matches (four matches in each phase) of the 2009–2010 Brazilian Basketball League. Distance covered, number of match interruptions, and referees’ %HR and [lac] were analyzed. We compared the results between competition phases and between MPs (1st MP, 2nd MP, 3rd MP, and 4th MP). Results Regarding the distances covered, we observed significant differences (P < 0.05) in the 1st, 2nd, and 3rd MPs between the FP and the other two phases (SP and QP) throughout the match, between each phase; in the 4th MP, a significant difference was found when comparing the QP and the other two phases. Comparing the periods within each phase, we found that a greater distance was covered in the 4th MP in relation to the 3rd MP during the FP. No significant differences were found among the remaining variables. Conclusion The distances covered by referees in a basketball match increase throughout competition phases. This information is essential for planning of training and for the subsequent success of a referee.

Modelo competitivo da distância percorrida por futebolistas na Uefa Euro 2008

ABSTRACT: The aim of this study focuses on knowing the competitive model of distance covered by soccer players in the Uefa Euro 2008, in the positions of the game, times and the total distance covered during the matches. It was analyzed all matches from 16 teams, totaling 31 games of which involved 460 soccer players. Subsequently, produced descriptive and inferential information. The main results show that: i) European soccer players elite covered 10232 ± 852m; ii) a midfielders (10894 ± 648m) greater distance covered, followed by external defenders (10274 ± 694m), forwards (10108 ± 624m), central defenders (9498 ± 592m) and goalkeepers (4198 ± 610m); iii) the average of covered distance at first half (4907 ± 201m) for matches was higher than the second half (4890 ± 238m). KEY WORDS: Competitive model group; distance covered; soccer. modelo competitivo de la distancia recorrida por futbolistas en UefaEuro 2008 RESUMEN: El objetivo de este estudio se centra en conocer el modelo competitivo de la distancia recorrida por futbolistas en Uefa Euro 2008, por las posiciones de juego, tiempos y la distancia total recorrida durante los partidos. Se analizaron todos los juegos de 16 selecciones, totalizando 31 juegos que participaron 460 futbolistas. Posteriormente, fue-ran producidas informaciones descriptivas e inferencia. Los principales resultados indican que: i) futbolistas de la elite Europea recorreran 10232 ± 852m; ii) centro-campistas (10894 ± 648m) recorreran mayor distancia, seguido por laterales (10274 ± 694m), delanteros (10108 ± 624m), defensores (9498 ± 592m) y porteros (4198 ± 610m); iii) la media distancia recorrida en lo 1o tiempo (4907 ± 201m) de los juegos fue superior a 2o tiempo (4890 ± 238m). PALABRAS CLAVES: Modelos competitivos; distancia recorrida; futbol.

Effects of the neuromuscular training in the cardiorespiratory fitness and body composition of female volleyball athletes

As respostas do organismo humano submetido a estimulos diversos, mensuradas atraves de parâmetros de performance, tem sido objeto de estudo a fim de aprimorar os metodos de treinamento. O objetivo deste estudo foi investigar os efeitos do treinamento neuromuscular na capacidade cardiorrespiratoria e composicao corporal de atletas de voleibol. Foram avaliadas 11 mulheres, antes e apos 12 semanas de treinamento, referente a fase preparatoria do ciclo anual de treinamento. O protocolo experimental constou de avaliacao da composicao corporal (percentual de gordura, massa magra e a gordura corporal) e da aptidao cardiorrespiratoria por meio de ergoespirometria em esteira rolante com protocolo continuo e carga crescente, na qual se determinaram o consumo maximo de oxigenio, a frequencia cardiaca maxima, o limiar anaerobio, a frequencia cardiaca do limiar anaerobio e a velocidade do limiar anaerobio. O treinamento teve frequencia de cinco dias por semana dividido em duas sessoes: uma de treinamento de forca e outra de treinamento tecnico e tatico. Apos o periodo estudado ocorreram aumentos (p < 0,05) no consumo maximo de oxigenio (6,5%), no limiar anaerobio (17,5%), na velocidade do limiar (15,3%) e reducao (p < 0,05) na frequencia cardiaca maxima (-3,1%). Tambem houve reducao (p < 0,05) no percentual de gordura (-8,2%), na gordura corporal (-7,4%) e aumento (p < 0,05) na massa magra (3,2%). Conclui-se que o treinamento neuromuscular realizado na fase preparatoria de treinamento contribuiu para o aumento da capacidade cardiorrespiratoria e massa magra e para reducao do percentual de gordura e a gordura corporal das atletas de voleibol.

Monitoring of immunological parameters in adolescent basketball athletes during and after a sports season

Abstract The objective of the present study was to monitor the immunological and hormonal responses and the occurrence of upper respiratory symptoms in adolescent basketball athletes during the different stages of a sports season. Anthropometric measures, biochemical analyses (interleukin-6, interleukin-10, tumour necrosis factor-alpha, C-reactive protein, testosterone and cortisol), neuromuscular evaluations (standing vertical jumping ability, agility and estimated VO2max) and leukocyte counts were performed at four moments: 72 h before the season (−72 h); before the season (Pre-season); after six weeks, at the end of the preparatory period (Preparatory); and after 20 weeks, at the end of the competitive period (Competitive). Also, the occurrence of upper respiratory symptoms was collected weekly during all stages of the season. There were significant increases in monocytes, cortisol, tumour necrosis factor-alpha and C-reactive protein at the Competitive moment as compared to the Pre-season. In addition, interleukin-10 decreased at the Competitive moment as compared to the Pre-season. Occurrence of upper respiratory symptoms demonstrated increases (38%) during the competitive period as compared to the preparatory. These results suggest that periods of training and competition could increase the occurrence of upper respiratory symptoms in adolescent athletes and this may be due to the unwanted effects of an inflammatory process in response to the excessive stress of training and competition.

The Influence of Whole-Body Vibration on Creatine Kinase Activity and Jumping Performance in Young Basketball Players

Purpose To quantify creatine kinase (CK) activity changes across time following an acute bout of whole-body vibration (WBV) and determine the association between changes in CK activity and jumping performance. Method Twenty-six elite young basketball players were assigned to 3 groups: 36-Hz and 46-Hz vibration groups (G36 and G46, respectively) and a control group. The study quantified CK activity and jumping performance following an acute bout of WBV at 2 vibration frequencies. Both WBV groups performed a protocol that consisted of 10 sets of 60 s of WBV while standing on a vibration plate in a quarter-squat position. CK activity, countermovement jumps (CMJ), and squat jumps (SJ) were measured immediately before and 24 hr and 48 hr after WBV. In addition, CMJ and SJ were also measured 5 min after WBV. Results CK activity was statistically significantly increased 24 hr following WBV in G36 and G46. At 48 hr after WBV, CK activity was similar to baseline levels in G36 but remained statistically significantly above baseline levels in G46. The CMJ and SJ heights were statistically significantly decreased at 5 min following the protocol for both WBV groups. Overall, the changes in CK activity did not present a strong relationship with the changes in jump heights for any of the comparisons. Conclusions These findings suggest that WBV protocols with such characteristics may not cause excessive muscle damage and may partly explain why many WBV training studies have failed to elicit increases in strength performance.