Stress Levels in Handball Coaching-Case Study: Preliminary Analysis of the Differences between Training and Match.

Stress plays a significant role in competitions and in the training of sports participants, and coaches are no exception. To better cope with stressful situations, close monitoring of coaches' stress levels before, during, and after training and competitions is recommended. According to studies, the use of cortisol (C) and alpha-amylase (AA) as biomarkers for monitoring acute stress is recommended. Therefore, the aim of our study was to compare HR, salivary C and AA, and STAI scores before, during, and after handball matches and training sessions. The study examined one professional handball coach, aged 37, in stress markers (salivary cortisol (C) and alpha-amylase (AA) concentrations), heart rate (HR), and the State-Trait Anxiety Inventory (STAI) scores in five matches/training sessions in the First Qatar Handball League. Statistical analysis included the calculation of descriptive statistic parameters, Mann-Whitney U test for differences between match-training time points, and the effect size analysis (Cohen's d) to calculate the magnitude of differences between match-training time points. Presented markers (C and AA) had statistically stronger reactions before, during, and after the matches than the corresponding time points of the training sessions, similar to HR data and STAI scores. Results indicate that, before and during the matches, the analyzed markers of stress increased, which might lead to the conclusion that coaches are more anxious than frightened before and during matches. Thus, stress-coping strategies for handball coaches should be more focused on stress anticipation and anxiety control.

Acute Effects of Different Plyometric and Strength Exercises on Balance Performance in Youth Weightlifters.

Background: High-intensity muscle actions have the potential to temporarily improve the performance which has been denoted as postactivation performance enhancement. Objectives: This study determined the acute effects of different stretch-shortening (fast vs. low) and strength (dynamic vs. isometric) exercises executed during one training session on subsequent balance performance in youth weightlifters. Materials and Methods: Sixteen male and female young weightlifters, aged 11.3±0.6years, performed four strength exercise conditions in randomized order, including dynamic strength (DYN; 3 sets of 3 repetitions of 10 RM) and isometric strength exercises (ISOM; 3 sets of maintaining 3s of 10 RM of back-squat), as well as fast (FSSC; 3 sets of 3 repetitions of 20-cm drop-jumps) and slow (SSSC; 3 sets of 3 hurdle jumps over a 20-cm obstacle) stretch-shortening cycle protocols. Balance performance was tested before and after each of the four exercise conditions in bipedal stance on an unstable surface (i.e., BOSU ball with flat side facing up) using two dependent variables, i.e., center of pressure surface area (CoP SA) and velocity (CoP V). Results: There was a significant effect of time on CoP SA and CoP V [F(1,60)=54.37, d=1.88, p<0.0001; F(1,60)=9.07, d=0.77, p=0.003]. In addition, a statistically significant effect of condition on CoP SA and CoP V [F(3,60)=11.81, d=1.53, p<0.0001; F(3,60)=7.36, d=1.21, p=0.0003] was observed. Statistically significant condition-by-time interactions were found for the balance parameters CoP SA (p<0.003, d=0.54) and CoP V (p<0.002, d=0.70). Specific to contrast analysis, all specified hypotheses were tested and demonstrated that FSSC yielded significantly greater improvements than all other conditions in CoP SA and CoP V [p<0.0001 (d=1.55); p=0.0004 (d=1.19), respectively]. In addition, FSSC yielded significantly greater improvements compared with the two conditions for both balance parameters [p<0.0001 (d=2.03); p<0.0001 (d=1.45)]. Conclusion: Fast stretch-shortening cycle exercises appear to be more effective to improve short-term balance performance in young weightlifters. Due to the importance of balance for overall competitive achievement in weightlifting, it is recommended that young weightlifters implement dynamic plyometric exercises in the fast stretch-shortening cycle during the warm-up to improve their balance performance.

Investigating the Prevalence and Predictors of Injury Occurrence in Competitive Hip Hop Dancers: Prospective Analysis.

Hip hop is a popular form of competitive and recreational sport worldwide, but studies rarely investigate injury prevalence and factors associated with injury occurrence in this sport. This study aimed to prospectively examine injury occurrence in hip hop dancers in a three-month period and to evaluate potential predictors of injury occurrence in hip hop dancers. The participants were 129 competitive hip hop dancers (114 females, 17.95 ± 4.15 years of age). Study predictors were obtained at study baseline and included sociodemographic factors, sport-related factors, previous injury status, anthropometric and body build indices (body height, mass, body mass index, and body composition variables), and dynamic balance performance (obtained by the Star Excursion Balance Test-SEBT). The outcome was injury occurrence, which was prospectively observed once a week by the Oslo Sports Trauma Research Center Overuse Injury Questionnaire (OSTRC). During the course of the study, 101 injuries occurred, equating to an annual injury incidence of 312%. On average, each dancer suffered 0.78 injuries (95% Confidence Interval (95% CI): 0.61-0.97) across a study period of three months (0.76 (95% CI: 0.60-0.95) and 0.93 (95% CI: 0.75-1.13), in females and males, respectively; Mann Whitney Z-value: 0.68, p = 0.52). Seventeen percent of dancers suffered multiple injuries, and 49% of all injuries were time-loss injuries. The knee was the most frequently injured body location (42% of all reported injuries), followed by the back region (32%) and the ankle (15%). Previous injury was a strong predictor of injury occurrence (Odds Ratio: 3.76, 95% CI: 1.87-4.59). Lower injury risk was evidenced among those participants who achieved better scores on several SEBT variables, irrespective of gender and previous injury status; with no significant influence of anthropometric and body build variables on injury occurrence. This study highlighted a high injury rate in hip hop dancers. Dancers and coaches should be informed about the certain protective effects of dynamic balance on the prevention of musculoskeletal injury in hip hop in order to assure safe and effective practices. The usage of SEBT as a convenient and cheap testing procedure is encouraged in other dance disciplines.

The Prevalence and Covariates of Potential Doping Behavior in Kickboxing; Analysis among High-Level Athletes.

The official reports on doping behavior in kickboxing are alarming, but there have been no empirical studies that examined this problem directly. The aim of this study was to investigate the prevalence, gender differences and covariates of potential-doping-behavior, in kickboxing athletes. A total of 130 high-level kickboxing athletes (92 males, 21.37 ± 4.83 years of age, 8.39 ± 5.73 years of training experience; 38 women, 20.31 ± 2.94 years of age; 9.84 ± 4.74 years of training experience) completed questionnaires to study covariates and potential-doping behavior. The covariates were: sport factors (i.e. experience, success), doping-related factors (i.e. opinion about penalties for doping users, number of doping testing, potential-doping-behavior, etc.), sociodemographic variables, task- and ego-motivation, knowledge on sports nutrition, and knowledge on doping. Gender-based differences were established by independent t-tests, and the Mann-Whitney test. Multinomial logistic regression analyses were performed to define the relationships between covariates and a tendency toward potential-doping behavior (positive tendency - neutral - negative tendency). The potential-doping behavior was higher in those athletes who perceived kickboxing as doping contaminated sport. The more experienced kickboxers were associated with positive intention toward potential-doping behavior. Positive intention toward potential-doping behavior was lower in those who had better knowledge on sports nutrition. The task- and ego-motivation were not associated to potential-doping behavior. Because of the high potential-doping-behavior (less than 50% of athletes showed a negative tendency toward doping), and similar prevalence of potential-doping behavior between genders, this study highlights the necessity of a systematic anti-doping campaign in kickboxing. Future studies should investigate motivational variables as being potentially related to doping behavior in younger kickboxers.

Sport nutrition and doping in tennis: an analysis of athletes' attitudes and knowledge.

Nutrition and doping issues are rarely studied in the sport of tennis. The aims of this investigation were to determine knowledge on doping (KD) and knowledge on sport nutrition (KSN), and corresponding socio-demographic-, sport-, and sport-nutrition- and doping-factors among an international sample of high-level tennis players of both sexes (43 females; 22 years old on average). In the first phase of the investigation, the KSN and KD questionnaires were studied for their reliability and validity. The consumption of NS is found to be very high, with almost of all the females and 80% of the males using NS at least occasionally. The athletes showed a low tendency regarding future doping usage, although most of them are convinced that doping does exist in tennis. Since athletes declared that their coaches are their main source of information about NS and doping, future studies should investigate what coaches actually know about such problems. KSN has been found to be protective against potential doping behavior in the future. Males are found to be more prone to doping than females. Therefore, in order to prevent doping behavior in tennis we strongly suggest intensive educational programs on sports nutrition and doping-related problems. Key PointsThe incidence of nutritional supplementation use among the tennis players is found to be very high, especially among the females.Although most of the subjects are of the opinion that the doping behavior is present in tennis circuit, we have found a low tendency regarding future doping usage, and high levels of athletes' trust in their coaches with regard to nutritional supplementation and doping.There are indices that the knowledge about nutrition is protective factor against potential doping behavior. It clearly reinforces the need to include a wide educational program on sports nutrition in tennis, but also in other sports.

The training effects of dance aerobics: A review with an emphasis on the perspectives of investigations.

The training effects of contemporary aerobics programmes (hi lo, dance aerobics, step aerobics, aqua aerobics etc.) have been frequently investigated. However, we found no recent paper which reviewed aerobic programmes with regard to their training effectiveness, characteristics of the subjects involved, variables of interest and experimental design. In this paper we summarise the findings of more than 40 studies published in the 2000-2011 period that investigated the training effects of different forms of contemporary aerobics. In this review, the studies are grouped according to their characteristics (sample of subjects, variables of interest, study design, effects, etc.). Around 80% of the investigations dealt with females, with adults being most commonly observed. In the majority of investigations, the authors studied different variables at the same time (morphological anthropometric, motor, cardiovascular, biochemical indices, etc.). In recent studies a trend toward a psychological status examination is evident. In most instances positive training effects on motor-endurance and varsity of physiological variables are declared throughout a training period of 8 to 12 weeks. However, the positive changes in anaerobic endurance are not evidenced. Knowing the tendency of the overall increase of certain psychological disorders in population (including depression) there are indications that future, potentially highly interesting studies will deal with the psychological status of adults and older subjects.

A retrospective survey on injuries in Croatian football/soccer referees.

BACKGROUND: Injury among soccer referees is rarely studied, especially with regard to differences in the quality level of the refereeing. Additionally, we have found no study that has reported injury occurrence during official physical fitness testing for soccer referees. The aim of this study was to investigate the frequency, type and consequences of match-related and fitness-testing related injuries among soccer referees of different competitive levels. METHODS: We studied 342 soccer referees (all males; mean age 32.9 ± 5.02 years). The study was retrospective, and a self-administered questionnaire was used. In the first phase of the study, the questionnaire was tested for its reliability and applicability. The questionnaire included morphological/anthropometric data, refereeing variables, and musculoskeletal disorders together with the consequences. RESULTS: The sample comprised 157 main referees (MR; mean age 31.4 ± 4.9 years) and 185 assistant referees (AR; mean age 34.1 ± 5.1 years) divided into: international level (Union of European Football Associations-UEFA) referees (N = 18; 6 MRs; 12 ARs) ; 1st (N = 78; 31 MRs; 47 ARs), 2nd (N = 91; 45 MRs; 46 ARs); or 3rd national level referees (N = 155; 75 MRs; 80 ARs). In total, 29% (95%CI: 0.23-0.37) of the MRs and 30% (95%CI: 0.22-0.36) of the ARs had experienced an injury during the previous year, while 13% (95%CI: 0.05-0.14) of the MRs, and 19% (95%CI: 0.14-0.25) of the ARs suffered from an injury that occurred during fitness testing. There was an obvious increase in injury severity as the refereeing advanced at the national level, but the UEFA referees were the least injured of all referees. The results showed a relatively high prevalence of injuries to the upper leg (i.e., quadriceps and hamstrings) during physical fitness testing for all but the UEFA referees. During game refereeing, the ankles and lower legs were the most commonly injured regions. The MRs primarily injured their ankles. The ARs experienced lower leg and lower back disorders. However, the overall injury rate was equal for both groups, with 5.29 (95%CI: 2.23-8.30) and 4.58 (95%CI: 2.63-6.54) injuries per 1000 hours of refereeing for MRs and ARs, respectively. CONCLUSION: In addition to the reported risk of injury during soccer games, physical fitness testing should be classified as a risk for injury among soccer referees. Special attention should be given to (I) lower leg injuries during games and (II) upper leg injuries during physical fitness tests. A higher physical fitness level and a qualitative approach to training are recognized as protective factors against injury. Subsequent studies should investigate the specific predictors of injuries among referees.

General anthropometric and specific physical fitness profile of high-level junior water polo players.

The aim of this study was to investigate the status and playing position differences in anthropometric measures and specific physical fitness in high-level junior water polo players. The sample of subjects comprised 110 water polo players (17 to 18 years of age), including one of the world's best national junior teams for 2010. The subjects were divided according to their playing positions into: Centers (N = 16), Wings (N = 28), perimeter players (Drivers; N = 25), Points (N = 19), and Goalkeepers (N = 18). The variables included body height, body weight, body mass index, arm span, triceps- and subscapular-skinfold. Specific physical fitness tests comprised: four swimming tests, namely: 25m, 100m, 400m and a specific anaerobic 4x50m test (average result achieved in four 50m sprints with a 30 sec pause), vertical body jump (JUMP; maximal vertical jump from the water starting from a water polo defensive position) and a dynamometric power achieved in front crawl swimming (DYN). ANOVA with post-hoc comparison revealed significant differences between positions for most of the anthropometrics, noting that the Centers were the heaviest and had the highest BMI and subscapular skinfold. The Points achieved the best results in most of the swimming capacities and JUMP test. No significant group differences were found for the 100m and 4x50m tests. The Goalkeepers achieved the lowest results for DYN. Given the representativeness of the sample of subjects, the results of this study allow specific insights into the physical fitness and anthropometric features of high-level junior water polo players and allow coaches to design a specific training program aimed at achieving the physical fitness results presented for each playing position.

Pulmonary function in pubertal synchronized swimmers: 1-year follow-up results and its relation to competitive achievement.

Pulmonary function (PF) is particularly important in synchronized swimming, considering the characteristics of this sport. However, the sanitizing agents (chlorine) used in pools can have a possible negative influence on the PF parameters. In this study, we observed 24 swimmers (all women, 14 to 16 years of age) and measured their PF and competitive achievement. PF was measured before and after a 1-year period and included standard spirometric variables. Competitive achievement was evidenced during the National Championship. The t-test showed significant increases in body height and weight of the participants and a resulting increase in most of the absolute respiratory flows and pulmonary capacities. Forced vital capacity (FVC) and forced expiratory volume (both in proportion to norm for body height, gender, and age) increased significantly within the study period. FVC significantly predicted the competitive achievement of young swimmers, most probably because artists have to achieve exceptional breath control when upside down underwater. In conclusion, we found no evidence for the eventual negative influence of chlorine and its compounds on the PF of swimmers, and results showed that regular synchronized swim training could improve the PF of young artists.