Research Quarterly for Exercise and Sport最新文献

Purpose: The aim of this 2-week randomized, counterbalance and crossover study was to investigate the effect of acute mental fatigue (MF) on tennis serve performance and accuracy in tennis players. Methods: Ten male tennis players (18 ± 4 years, 1.80 ± 0.08 m; 71 ± 13 kg) were randomized to either the MF group (N = 5) that underwent an acute MF protocol or to a control (CON) group (N = 5). The MF condition consisted in a 30-min modified Stroop color word task performed before on-court serve speed test. A visual analogue scale (VAS) was used to assess the perceptions of MF and motivation toward the upcoming technical tests. Results: Reduction over baseline score of Stroop test was noted in accuracy (N < .001), but not in reaction time (N = .968) in the MF group. Increments in perceived workload were detected (N < .001) in MF group compared to CON. No differences for first and second serve speed from deuce and advantage side were observed. Increment of percentage of failed second serves from the deuce side (N = .043) in MF were detected. Conclusions: An acute MF protocol reduced tennis serve accuracy from deuce side in male tennis players. Players should avoid cognitive efforts before training sessions and matches to prevent negative effects of their technical performance.

Purpose: Physical education (PE) teachers play an important role in concussion recognition and management in schools both in an academic and activity based setting. This study aimed to identify Irish post-primary PE teachers' concussion knowledge, beliefs, education and management practices. Methods:  An anonymous online survey, adapted to the Irish context from the validated BAKPAC-TEACH, was completed by 128 PE teachers (female = 74/123; 60.2%; male = 49/123; 39.8%, 36.1 ± 10.9 years), representing 4% of registered PE teachers in Ireland. Results: PE teachers reported 3.5 ± 4.7 students suffer with a sports-related concussion in their classroom annually and 43.9% previously had a student sustain a concussion during their PE class. Most received concussion education (58.6%), largely provided by sporting bodies. They frequently identified dizziness (93.0%) and headaches (92.2%) as concussion symptoms, but less commonly emotional (more emotional = 36.5%, nervous or anxious = 33.6%, sadness = 28.9%) or sleep (35.2%) symptoms. All PE teachers knew that a concussion requires immediate removal from a game/practice. PE teachers demonstrated less perceived knowledge and confidence relating to academic adjustments and return to learn criteria. Just 31.3% reported their school facilitates academic adjustments. Conclusion: Tailored concussion education addressing knowledge gaps highlighted in this study should be developed. A concussion policy and an academic support team in each school should be established and widely publicised to enhance the support of concussed students in returning to school.

Purpose: This study: (1) Described the knowledge, attitudes, and reported behavior intentions of young recreational football players' parents toward concussion. (2) Investigated associations of the previous variables with parent demographics. Materials and Methods: A cross-sectional design utilized an online platform to survey parents of children (8-14 yrs.) in three youth football leagues in the southern United States. Demographics collected included items such as sex or concussion history. Knowledge was assessed via true/false items, with higher scores (0-20) representing greater concussion understanding. 4-point Likert scales were used to describe parents attitudes (1 = not at all, 4 = very much), confidence in intended recognition/reporting (1 = not-confident, 4 = extremely confident), and agreement with intended reporting behaviors (1 = strong- disagreement, 4 = strong-agreement). Descriptive statistics were calculated for demographics. Mann-Whitney U test or Kruskal-Wallis Tests examined survey responses across demographics. Results: Respondents (n = 101) were primarily female (64.4%), white (81.2%), and participated in contact sport (83.2%). Parents averaged 15.9 ± 1.4 on concussion knowledge, with only 34.7% (n = 35) of parents scoring > 17/20. Statements that received the lowest average agreement (3.29/4) regarding reporting intent were related to emotional symptoms. Some parents (n = 42, 41.6%) reported low confidence in recognizing symptoms of a concussion in their child. Parent demographics did not have clinically significant associations with survey responses, with 6/7 demographic variables resulting in no statistical significance (p > .05). Conclusions: Although one-third of parents attained high knowledge scores, several reported low confidence in recognizing concussion symptoms in their children. Parents scored lower in agreement with removing their child from play when concussion symptoms were subjective. Youth sports organizations providing concussion education to parents should consider these results when revising their materials.

Purpose: Near-infrared spectroscopy (NIRS) indices during arterial occlusion-reperfusion maneuver have been used to examine the muscle's oxidative metabolism and microvascular function-important determinants of whole-body aerobic-fitness. The association of NIRS-derived parameters with whole-body VO₂max was previously examined using a method requiring exercise (or electrical stimulation) followed by multiple arterial occlusions. We examined whether NIRS-derived indices of muscle deoxygenation and microvascular reactivity assessed during a single occlusion-reperfusion at rest are (a) associated with maximal/submaximal indices of whole-body aerobic-fitness and (b) could discriminate individuals with different VO₂max. We, also, investigated which NIRS-parameter during occlusion-reperfusion correlates best with whole-body aerobic-fitness. Methods: Twenty-five young individuals performed an arterial occlusion-reperfusion at rest. Changes in oxygenated- and deoxygenated-hemoglobin (O₂Hb and HHb, respectively) in vastus-lateralis were monitored; adipose tissue thickness (ATT) at NIRS-application was assessed. Participants also underwent a maximal incremental exercise test for VO₂max, maximal aerobic velocity (MAV), and ventilatory-thresholds (VTs) assessments. Results: The HHbslope and HHbmagnitude of increase (occlusion-phase) and O₂Hbmagnitude of increase (reperfusion-phase) were strongly correlated with VO₂max (r = .695-.763, p < .001) and moderately with MAV (r = .468-.530; p < .05). O₂Hbmagnitude was moderately correlated with VTs (r = .399-.414; p < .05). After controlling for ATT, the correlations remained significant for VO₂max (r = .672-.704; p < .001) and MAV (r = .407; p < .05). Individuals in the high percentiles after median and tritile splits for HHbslope and O₂Hbmagnitude had significantly greater VO₂max vs. those in low percentiles (p < .01-.05). The HHbslope during occlusion was the best predictor of VO₂max. Conclusion: NIRS-derived muscle deoxygenation/reoxygenation indices during a single arterial occlusion-reperfusion maneuver are strongly associated with whole-body maximal indices of aerobic-fitness (VO₂max, MAV) and may discriminate individuals with different VO₂max.

Purpose: Despite the known health and wellbeing benefits of taking part in sport for children and adolescents, it is reported that sports participation declines during adolescence. The purpose of this study was to explore current organized youth sport participation rates across Europe for both males and females and update current understanding. Method: Sport participation registration data was collected for 18 sports from 27 countries. In total, participation data was collected from over 5 million young people from Under 8s (U8s) to Under 18s (U18s). Differences in the participation rates between age categories were investigated using a generalized linear mixed effects model. Results: Overall, males were four times more likely to participate in organised youth sport than females' participants, with this trend apparent across all age categories and across most sports. There was a significant decrease across sports in participation rates for males during adolescence from U14-U16 and U16-U18. There was a significant decrease in participation rates for females from U14-U16 for most sports except but an increase in participation rates from U16-U18 for 12 out of 18 sports. Soccer (1262%), wrestling (391%) and boxing (209%) were the sports that had greater male sport participation rates. In contrast, dance sports (86%) and volleyball (63%) had more female participants than males. This research shows male sports participation is significantly greater than female in youth sport across Europe. Conclusion: Furthermore, findings showed that for both male and female participants, participation rates increased from U8-U14 for the majority of sports followed by reduced participation rates during adolescence. Findings of this research can be used by national governing bodies and sporting organizations to inform youth sport participation initiatives.

In volleyball, the effect of different factors on serve performance has usually been analyzed with traditional statistical techniques such as logistic regression or discriminant analysis. Purpose: In this study, two of the main models used in unsupervised machine learning (cluster and principal component analysis) were applied to achieve these objectives: (a) to create groups of players considering their serve coefficient, age, height, and team ranking, and (b) to identify which variables related to the serve (type and performance), the players (role, age, and height), and the teams (ranking, match location, and quality of opposition) most explained the total variance of the data during an entire women's volleyball season. Method: A total of 20,936 serves were analyzed during the 132 matches played in the 2017-2018 season in the Liga Iberdrola (women Spanish first division). The variables were related to the serving action (type of serve and performance), the players' traits (player role, age, and height), and the teams' characteristics (final ranking, match location, quality of opposition, and tournament). Results: Cluster analysis showed five groups of players differing in age, serve coefficient, team ranking, and height. Principal component analysis showed how the first five components explained 72.12% of the total variance. From these components, serve coefficient, team ranking, match location, quality of opposition, and player role each contributed more than 10%. Conclusions: These findings can help coaches to improve talent selection and players' development according to competition demands.

Background: Functional training (FT) has become popular and seems to provoke health benefits. However, there are unsubstantiated claims regarding energy expenditure (EE) vs. weight-loss and cardiorespiratory improvements linked to FT. Objective: This study quantified the EE and intensity during FT performed in a conventional fitness center. Additionally, data of FT and moderate continuous walking (WLK) were compared. Methods: Healthy individuals with no previous experience with FT [n = 25, 11 males/14 females, 38.8 ± 9.3 years; 73.9 ± 13.8 Kg; 168.5 ± 8.5 cm; 26.0 ± 4.5 Kg/m2; 16 overweight (BMI >25 Kg/m2)] performed three FT sessions interspersed with 48 h (two familiarization, one assessment). The circuit included 4 rounds of 12 exercises performed at all-out intensity for 20 s with 1-min intervals between rounds. WLK was performed for 25 min with intensity corresponding to scores 3-5 on Borg CR-10 Scale. Outcomes were EE (kcal), movement counts estimated by triaxial accelerometry, heart rate reserve (%HRR), and rate of perceived exertion (RPE). Results: On average, FT sessions lasted 24 min and EE ranged between 124 and 292 kcal (188 ± 41 kcal), corresponding to 5-8 METs (6.1 ± 0.6 METs), and 70-80%HRR (74 ± 8%). Accelerometry (counts/min) showed that vigorous predominated over moderate intensity during FT and WLK (p = .01), with similar EE. The relative intensity and RPE were higher in FT vs. WLK (74% vs. 55%HRR and Borg 5-8 vs. 3-5, respectively; p < .0001). Conclusion: FT and WLK elicited EE consistent with recommendations to reduce cardiovascular disease risk, but only FT achieved relative intensities compatible with cardiorespiratory improvement. FT should be considered an option in health-oriented exercise programs for the general population.

Purpose: Physical education requirements (PERs) have been suggested as a potential solution for increasing physical activity (PA) among undergraduate students, specifically for the inactive who face the greatest barriers to PA. In 2010, among a nationally-representative, random sample of tertiary institutions in the U.S. only 39% had PERs as part of their general education curriculum. But, being a decade old, this data may be outdated. The aim of this study was to examine the current status of PERs in U.S. tertiary institutions and to explore what institutional characteristics are associated with having a PER. Methods: Academic catalogs of a nationally representative, random sample of 331 institutions were searched for PER information. Results: The majority of U.S. tertiary institutions did not mandate physical education (PE) courses (56.2%), whereas 31.7% fully and 12% partially required their undergraduate students to complete a PE course to graduate. The characteristics most associated with an institution having a PER included being private, having a small enrollment size, having an academic degree program related to the field, having both activity and conceptual components, being <3 credit hours, offering an elective program in physical activity education, and being located in the south. Conclusion: Future work is needed to identify important elements of PER courses, reasons why PERs are sustained by some institutions versus others, and to establish practical guidelines regarding best practices for quality PER courses. More direct action within the discipline of kinesiology is needed to underscore the importance and need of PERs at the tertiary level.

Background and aims: Muscle strength (MS) has been associated with better cardiometabolic health prognosis. However, the result for the beneficial relationship seems to be dependent on the influence of body size in determining MS levels. We investigate the association between allometric MS indexes and its association with cardiometabolic risk factors in adolescents. Methods: It was a cross-sectional study comprising 351 adolescents (male: 44.4%; age range 14-19 years) from Southern Brazil. MS was assessed by handgrip strength and three different allometric approaches were adopted: 1) MS index based on theoretical allometric exponent; 2) MS index including body mass and height; 3) MS index including fat-free mass and height. Obesity, high blood pressure, dyslipidemia, glucose imbalance and high-sensitivity C-reactive protein were investigated as individual factors or as combinations (either as combinations of components - presence of two adverse conditions, or number of components present in an individual - 0, 1, 2, 3+ cardiometabolic risk factors). Logistic and multinomial logistic regression analyses adjusted for confounding factors were used. The statistical significance adopted was 5%. Results: MS index based on theoretical allometric exponent was associated with lower likelihood (OR: 0.54; 95% CI: 0.28 - 0.89) for the presence of three or more cardiometabolic risk factors in the same individual. Conclusion: This study suggests that MS index based on the theoretical allometric exponent can be superior to allometric MS indexes that included body mass and height, or fat-free mass and height in representing the presence of high number of cardiometabolic risk factors in adolescents.

Purpose: Psychological resilience is vital to the development of sport talents. Qualitative research has consistently demonstrated that sport resilience encapsulates a mixed package of resilience qualities (reflecting positive traits and characteristics) and resilience support (reflecting perceived support and related resources). Ironically, sport resilience research adopting quantitative methods has been assessing resilience as a unidimensional construct, with little attention to the multi-facet nature of resilience and its effects on performance. In the present research, we tested a novel proposition that resilience qualities predict reduced pre-competition cognitive anxiety and contribute to performance more than resilience support. Methods & Results: Across two samples of competitive table tennis players (Study 1: N = 196 competing at province level; Study 2: N = 106 competing at national level), we consistently found resilience qualities, rather than resilience support, predicted lower levels of pre-competition cognitive anxiety and superior performance at a national championship. Results also suggest that pre-competition cognitive anxiety mediated the relationship between resilience qualities and performance. Conclusion: The findings provide the first evidence supporting the divergent effects of resilience qualities and resilience support in predicting pre- competition anxiety and championship performance and call for the consideration of such a distinction when designing and delivering resilience programs.