Much research has been done in sports nutrition in recent years as the demand for performance-enhancing substances increases. Higher intake of nitrates from the diet can increase the bioavailability of nitric oxide (NO) via the nitrate–nitrite–NO pathway. Nevertheless, the increased availability of NO does not always lead to improved performance in some individuals. This review aims to evaluate the relationship between the athlete’s training status and the change in time trial performance after increased dietary nitrate intake. Articles indexed by Scopus and PubMed published from 2015 to 2019 were reviewed. Thirteen articles met the eligibility criteria: clinical trial studies on healthy participants with different training status (according to VO2max), conducting time trial tests after dietary nitrate supplementation. The PRISMA guidelines were followed to process the review. We found a statistically significant relationship between VO2max and ergogenicity in time trial performance using one-way ANOVA (p = 0.001) in less-trained athletes (VO2 < 55 mL/kg/min). A strong positive correlation was observed in experimental situations using a chronic supplementation protocol but not in acute protocol situations. In the context of our results and recent histological observations of muscle fibres, there might be a fibre-type specific role in nitric oxide production and, therefore, supplement of ergogenicity.
Purpose: Change of direction speed (CODS) and reactive agility (RAG) are important qual-ities in futsal, but studies rarely examined the predictors of these conditioning capacities in players of advanced level. This study aimed to evaluate predictive validity of certain an-thropometric and conditioning capacities in evaluation of futsal specific CODS and RAG in top-level players. Methods: The sample comprised 54 male players from Croatia and Bosnia and Herzegovina, members of teams competing at the highest national rank, including national champions for the 2017–2018 competitive season in both countries. The variables comprised set of pre-dictors (body mass, body height, triceps skinfold, reactive strength index [RSI], sprint 10 m [S10M], and broad jump [BJ]; and four criteria: futsal specific CODS and RAG, performed with and without dribbling (CODS_D, CODS_WD, RAG_D, RAG_WD). To identify the asso-ciation between variables Pearson’s correlation and multiple regressions were calculated. Results: Observed predictors explained statistically significant (p < 0.05) percentage of vari-ance for all four criteria (Rsq: 0.28, 0.30, 0.23 and 0.25, for CODS_WD, CODS_D, RAG_WD, RAG_D, respectively). Body mass was significant predictor for all criteria (Beta: 0.35–0.51), with poorer performances in heavier players. In both performances which involved dribbling, significant predictors was RSI (Beta: −0.27 and −0.31 for CODS_D and RAG_D, respective-ly), with superior performances in players with better RSI. The S10M and BJ were not identi-fied as being significantly correlated to studied RAG and CODS performances. Conclusion: Study confirmed specific influence of studied predictors of futsal specific CODS and RAG with consistent negative influence of body mass on studied performances. Almost certainly this can be explained by specifics of RAG and CODS execution. Specifically, tests are performed over relatively small distances, with several changes of direction, which clear-ly mimic the futsal specific performances. Although sprint performance is often observed as important determinant of CODS and RAG, herein we did not confirm its predictive validity in explanation of futsal specific CODS and RAG. Future studies should evaluate other poten-tially important predictors of these capacities in futsal.
IntroductionAthletes are often associated with a greater degree of risk behaviour. It also includes potentially dangerous sexual habits and behaviour, among other things. Athletes in many cases tend to have more sexual partners and shorter-term relationships. It has been shown that athletes have statistically more sexual partners and sexual activities, by comparing students who participate in regular sports activities and their non-sports opposites (Grossbard, Lee, Neighbors, Hendershot, & Larimer 2007;Wetherill & Fromme 2007). It does not always concern both sexes, because it is possible to observe the opposite trend in female athletes. Female athletes often have less sexual activity and sex partners, or less often have multiple partners than their nonsports counterparts (Allison 2016;Habel, Dittus, De Rosa, Chung & Kerndt 2010;Miller, Sabo, Farrell, Barnes & Melnick 1998). Interesting are the results of a study held on a large group of students that shows greater use of condoms by athletes than non-athletes (Taliaferro, Rienzo & Donovan 2010). In the light of this it is evident that athletes are not always or more frequently involved in all risky behaviour than non-athletes.We assume that increased sexual activity of athletes may be partly due to easier access to sexual partners, especially to those who are interest in short-term relationship. While in the strategy of selecting long-term partners, future husbands and fathers, apart from health factors such as access to resources, social status (or resource holding potential for young men) are more important; in men-selection strategies which women do Athletes are often associated with a greater degree of risk behaviour. It also includes potentially dangerous sexual habits and behaviour, among other things. This study deals with sexual habits and behaviour of combative athletes. The research sample (n-65) consists of representatives of various combat sports and these representatives are categorized into three groups: international (n-15), national (n-28), and regional competitors (n-22). Data were collected through the medium of a questionnaire which allowed us to compare results with sexual behaviour of Czech population over last 20 years. Athletes comprised in this study are more sexually active, have more sexual partners over the life, and tend to have various, risk sexual behaviour more likely than common Czech population. This phenomenon is more significant in elite athletes. We believe this could be affected by access to short-term relationships and by the awareness of athletes that they are attractive to women. In the light of these findings, we suggest to increase prevention of risky sexual behaviour for athletes in masculine sports. sexual habits, risky sexual behaviour, prevention, sexually transmitted illnesses
Overweight and obese children often suffer for many physiological and psychological is-sues. Resistance training allows them to excel over their peers due to strength ability which is related to their somatotype. The aim of this study was to examine the effect of an eight-week resistance training program on body composition in overweight and obese children. Study sample included 8 boys and 4 girls (age = 11.7 ± 1.54) who were involved in an eight-week strength specifically designed program consisted of two strength training unit per week. Resistance of exercise was set on 8‒10 RM. Body composition were measured by InBody 720 two times before and after the training intervention. The Wilcoxon matched pairs test was used. Results showed increase in total body weight (2.7%), lean body mass (2.5%) and fat mass (3.7%). This effect indicates that used resistance training program is suficient to lean body mass grow. Nevertheless, program proved to be inadequate to avoid an increase in fat mass. This could be caused by many factors which should be consider in further research (e.g. longer technique practice, diet, number of training units).
Purpose: The main aim of our research was to determine the internal load of goalkeepers in the soccer training process. The internal load of goalkeepers during the training process is examined according to the achieved values of heart rate. Our goal was to expand the knowl-edge of the impact of different methodical forms on the goalkeepers’ internal load in soccer, thereby support the possibilities of improving their training process. The assumption was that the goalkeepers would achieve significantly different heart rate values in different methodical forms. Methods: The research group was formed by six elite youth soccer goalkeepers (n=6) from U16, U17 and U19 categories. In order to evaluate the heart rate was used the POLAR PRO heart rate monitor and the loading zones of goalkeepers were determined by using a pro-gram called POLAR Team2. Subsequently, the obtained data were evaluated by using the Wilcoxon Signed-Rank Test and Cohen´s „r “(effect size). Results: The average difference in HRavg during preparatory exercise and small-sided game was 25 ± 9 beats.min-1, and the average difference in HRmax was 35 ± 12 beats.min-1. During preparatory exercise achieved the goalkeepers’ value of HRavg 134 ± 8 beats.min-1 and in small-sided game was HRavg 159 ± 8 beats.min-1. In individual methodical forms were found significantly different average heart rate values (z = -2.201, p < 0.05, r = 0.9), which statisti-cally and logically confirmed our assumption. Conclusion: Monitoring of soccer goalkeepers´ internal load in the process of training and improvement of game activities can greatly help the coaches in further planning, optimiza-tion and tracking of the training process. Based on our research´s results is recommended to monitor and evaluate the internal load intensity of goalkeepers using sporttesters during entire training process.
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