Low dose of dichloroacetate infusion reduces blood lactate after submaximal exercise in horses

The acute administration of an indirect activator of the enzyme pyruvate dehydroge-nase (PDH) in human athletes causes a reduction in blood lactate level during and after exercise. A single IV dose (2.5m.kg-1) of dichloroacetate (DCA) was administered before a submaximal incremental exercise test (IET) with five velocity steps, from 5.0 m.s-1 for 1 min to 6.0, 6.5, 7.0 and 7.5m.s-1 every 30s in four untrained mares. The blood collections were done in the period after exercise, at times 1, 3, 5, 10, 15 and 20 min. Blood lactate and glucose (mM) were determined electro-enzymatically utilizing a YSI 2300 automated analyzer. There was a 15.3% decrease in mean total blood lactate determined from the values obtained at all assessment times in both trials after the exercise. There was a decrease in blood lactate 1, 3, 5, 10, 15 and 20 min after exercise for the mares that received prior DCA treatment, with respective mean values of 6.31±0.90 vs 5.81±0.50, 6.45±1.19 vs 5.58±1.06, 6.07±1.56 vs 5.26±1.12, 4.88±1.61 vs 3.95±1.00, 3.66±1.41 vs 2.86±0.75 and 2.75±0.51 vs 2.04±0.30. There was no difference in glucose concentrations. By means of linear regression analysis, V140, V160, V180 and V200 were determined (velocity at which the rate heart is 140, 160, 180, and 200 beats/minute, respectively). The velocities related to heart rate did not differ, indicating that there was no ergogenic effect, but prior administration of a relatively low dose of DCA in mares reduced lactatemia after an IET.

Parents' support in the sports career of young gymnasts

From the very first moment of entrance in sports up to the time of their successful achievements, parents have a pronounced influence on the sport's career of their children. This influence is readily seen when the parent's dedicated involvement and investment, both emotional and financial, put into the support they give to their children in sports is taken into account. This is all done with the objective that their young athlete may stay involved and reach their full potential. To describe the parental support in the context of Brazilian Artistic Gymnastics in formative categories, this study addressed the perceptions that young gymnasts have toward the behavior and attitude of their parents through a field research conducted among 29 sport institutions involving a total of 163 athletes. We have found that parental support enabled and greatly influenced the child's entering into sports, their access to the practice of a sport, their level of participation, their degree of involvement, and their physical and emotional wellbeing. Moreover, the parental support is crucial to the commitment and dedication of the young gymnast. However, when this support is perceived in a negative way it can result in stress, conflicts between parents and children, burnout and may provoke dropout.

Exercise-induced muscle damage and running economy in humans

Running economy (RE), defined as the energy demand for a given velocity of submaximal running, has been identified as a critical factor of overall distance running performance. Plyometric and resistance trainings, performed during a relatively short period of time (15-30 days), have been successfully used to improve RE in trained athletes. However, these exercise types, particularly when they are unaccustomed activities for the individuals, may cause delayed onset muscle soreness, swelling, and reduced muscle strength. Some studies have demonstrated that exercise-induced muscle damage has a negative impact on endurance running performance. Specifically, the muscular damage induced by an acute bout of downhill running has been shown to reduce RE during subsequent moderate and high-intensity exercise (>65% VOax). However, strength exercise (i.e., jumps, isoinertial and isokinetic eccentric exercises) seems to impair RE only for subsequent high-intensity exercise (90% VOax). Finally, a single session of resistance exercise or downhill running (i.e., repeated bout effect) attenuates changes in indirect markers of muscle damage and blunts changes in RE. © 2013 Cláudio de Oliveira Assumpção et al.

Sports injuries among adolescent basketball players according to position on the court

Background: The participation of children and adolescents in sports, including basketball, is becoming increasingly common, and this increased involvement raises concerns about the potential risk of sports injuries. Objective. To analyze the occurrence of sports injuries among young basketball players according to their position on the court and to associate these injuries with risk factors. Method. A retrospective, epidemiological study. A sample consisting of 204 basketball players with a mean age of 14.33 ± 1.19 years participated in the study. The players were interviewed using a reported condition questionnaire containing anthropometric and training data as well as information on injuries during the previous 12 months. Results: The frequency of injury was highest among the shooting guards (47.8%), followed by the centers (34.8%) and point guards (17.4%). Among the 204 participants, 40 players reported a total of 46 injuries, representing 0.22 injuries per participant and 1.15 injuries per injured participant. For the shooting guards and centers, statistically significant differences between injured and non-injured players were found related to age, weight, height, length of time in training and number of weekly practice hours (p < 0.05). For point guards, a statistically significant difference between injured and non-injured players was found based on weight alone (p < 0.05). Conclusion: The occurrence of injuries among basketball players was low. Injuries were associated with both intrinsic and extrinsic factors among shooting guards and centers, whereas injuries were only associated with weight among point guards. © 2013 Vanderlei et al; licensee BioMed Central Ltd.

Mesenchymal stem cell therapy for equine tendinitis

Tendinitis is an important disease that leads to lameness and decreased performance in equine athletes and results in high costs associated with therapy due to a long recovery period and a high rate of recurrence. Although, several treatments for equine tendinitis have been described, few are effective in significantly improving the quality of the extracellular matrix and reducing the rate of recurrence. The use of cell therapy with mesenchymal stem cells (MSCs) derived from various sources has received much attention because of its therapeutic potential for equine tendinitis. In this paper, we review patents on stem cell therapy and the specific use of MSCs for the treatment of equine tendinitis. © 2013 Bentham Science Publishers.

Preconceito e esportes de aventura: A (não) presença feminina

Participation in adventure sports have increased recently, perhaps because of its appealing and emotional aspects. Despite this overall increase, women's participation is restricted due to ingrained gender prejudice in society, however, there are some initiatives aimed at expanding women's participation in several adventure sports. In scientific literature there is a lack of studies on adventure sports, especially on gender issues, prejudice and female athletic performance. These aspects motivated this study, which aims to investigate from the female athletes' perspective; the prejudice and behaviors of male athletes when in their presence and the male athletes' acceptance of them. This exploratory research consists of a qualitative study developed through an open on-line questionnaire. This tool was posted on web logs and websites of sixteen well-known female Brazilian adventure sports athletes. The questionnaire answers were analyzed based on the Thematic Content Analysis Technique and indicate that, although most female athletes do not report the prejudice and rejection of men, these attitudes appear subliminally, deserving more attention in future studies. © FTCD/FIP-MOC.

Rapid determination of furosemide by combined spot test/diffuse reflectance spectroscopy to detect doping in sport

This paper describes the development and application of a simple, cheap, and clean method for the quantification of furosemide in urine samples from athletes, to detect doping, using a combined spot test/diffuse reflectance spectroscopy procedure. The method is based on the complexation reaction of furosemide (5-(aminosulfonyl)-4-chloro-2-((furanylmethyl)amino)benzoic acid, dissolved in ethanol, with FeCl3 and the surfactant dodecyltrimethylammonium bromide (DTAB) in aqueous solution, yielding a colored compound on the surface of a filter paper. The reagent concentrations were optimized using a chemometric experimental design. The reflectometric measurements of the complex formed were carried out at 477nm. The linear range obtained was 1.65-9.00×10-3molL-1 of furosemide (R=0.997), and the detection and quantification limits were 4.9×10-4 and 1.62×10-3molL-1, respectively. The proposed method was successfully applied in the analysis of furosemide in spiked urine, demonstrating that it is a reliable alternative method for the detection of furosemide doping in sport. © 2012 Elsevier B.V..

Carbohydrate use and reduction in number of balance beam falls: Implications for mental and physical fatigue

Background: Artistic Gymnastics is a sport where athletes are frequently fatigued. One element that might influence this aspect is carbohydrate, an important energy substrate for the muscles and the CNS. Our goal was to investigate the influence of fatigue over artistic gymnastics athlete's performance and the effects of a carbohydrate supplementation on their performance. Methods: We evaluated 15 athletes divided in 2 groups (control and fatigue) from 12 to 14 years old in two different experimental days. On the first day (water day), they did 5 sets of exercises on the balance beam (experimental protocol) ingesting only water, CG (control group) warmed up before the experimental protocol and FG (fatigue group) did a fatigue circuit, warm up exercises and then the experimental protocol. On the second day (carbohydrate day), we used the same protocol but CG ingested a sugar free flavored juice and FG ingested a 20% concentration maltodextrin solution before the protocol on the balance beam. Results: We observed a greater number of falls from the balance beam from the FG on the first day (5.40 ± 1.14 FG vs 3.33 ± 1.37 CG; p = 0.024) and a decrease in the number of falls on the second day (2.29 ± 1.25 FG water day vs 5.40 ± 1.14 FG carbohydrate day; p = 0.0013). Carbohydrate solution was able to supply muscle demands and improve the athlete's focus showed by the reduced number of falls. © 2013 Batatinha et al.; licensee BioMed Central Ltd.

Validation of the lactate minimum test as a specific aerobic evaluation protocol for table tennis players

The purpose of this study was to validate the lactate minimum test as a specific aerobic evaluation protocol for table tennis players. Using the frequency of 72 balls·min-1 for 90 sec, an exercise-induced metabolic acidosis was determined in 8 male table tennis players. The evaluation protocol began with a frequency of 40 balls·min-1 followed by an increase of 8 balls·min-1 every 3 min until exhaustion. The mean values that corresponded to the subjects' lactate minimum (Lacmin) were equal to 53.1 ± 1.5 balls·min-1 [adjusted for the time test (Lacmin_time)] and 51.6 ± 1.6 balls·min-1 [adjusted for the frequency of balls (Lacmin_Freq)], which resulted in a high correlation between the two forms of adjustment (r = 0.96 and (P = 0.01). The mean maximum lactate steady state (MLSS) was 52.6 ± 1.6 balls·min-1. Pearson's correlations between Lacmin_time vs. MLSS and Lacmin_freq vs. MLSS were statistically significant (P = 0.03 and r = 0.86, P = 0.03 and r = 0.85, respectively). These findings indicate that the Lacmin test predicts MLSS. Therefore, it is an excellent method to obtain the athletes' anaerobic threshold. Also, there is the advantage that it can be performed in 1 day in the game area. However, the Lacmin value does not depend on the Lacpeak value.

Exploração de fatores de risco na natação

Pós-graduação em Fisioterapia - FCT

Relação entre parâmetros fisiológicos aeróbios e anaeróbios com o desempenho de ciclistas

Pós-graduação em Fisioterapia - FCT

Modelo da velocidade crítica em testes de caminhada: validade, reprodutibilidade e aplicabilidade em pacientes de Unidades de Saúde

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Padrão de coordenação do pular corda: um estudo desenvolvimental

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Influência das concentrações de marcadores bioquímicos de supertreinamento sobre as performances aeróbia e anaeróbia durante periodização em natação

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Correlações entre os valores de lactato mínimo e potência anaeróbia com a potência crítica e a capacidade de trabalho anaeróbio obtidas por método invasivo e não invasivos

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)