Sprint kayaking and canoeing performance prediction based on the relationship between maturity status,anthropometry and physical fitness in young elite paddlers

This study aimed to identify the maturity-related differences and its influence on the physical fitness, morphological and performance characteristics of young elite paddlers. In total, 89 kayakers and 82 canoeists, aged 13.69 ± 0.57 years (mean ± s), were allocated in three groups depending on their age relative to the age at peak height velocity (pre-APHV, circum-APHV and post-APHV) and discipline (kayak and canoe). Nine anthropometric variables, a battery of four physical fitness tests (overhead medicine ball throw, countermovement jump, sit-and-reach test and 20 m multistage shuttle run test) and three specific performance tests (1000, 500 and 200 m) were assessed. Both disciplines presented significant maturity-based differences in all anthropometric parameters (except for fat and muscle mass percentage), overhead medicine ball throw and all performance times (pre > circum > post; P < 0.05). Negative and significant correlations (P < 0.01) were detected between performance times, chronological age and anthropometry (body mass, height, sitting height and maturity status), overhead medicine ball throw and sit and reach for all distances. These findings confirm the importance of maturity status in sprint kayaking and canoeing since the more mature paddlers were also those who revealed largest body size, physical fitness level and best paddling performance. Additionally, the most important variables predicting performance times in kayaking and canoeing were maturity status and chronological age, respectively.     

Association of different types of playing surfaces with bone mass in growing girls

The aim of this cross-sectional study was to compare bone mass in young female athletes playing ball games on different types of playing surfaces. About 120 girls, 9–13 years of age (10.6 ± 1.5 years old Tanner I–III) were recruited and divided into prepubertal and pubertal groups. The sample represented 3 groups of athletes: soccer (N = 40), basketball (N = 40), and handball (N = 40); and 6 different playing surfaces (soccer – ground, soccer – artificial turf, basketball – synthetic, basketball – parquet, handball – synthetic, and handball – smooth concrete). Total and regional body composition (bone mass, fat mass, and lean mass) were measured by dual-energy X-ray absorptiometry (DXA). The mechanical properties of the surfaces (force reduction, vertical deformation, and energy return) were measured with the Advanced Artificial Athlete (Triple A) method. The degree of sexual development was determined using Tanner test. The pubertal group showed that soccer players on the ground, basketball players on synthetic, and handball players on smooth concrete had higher values of bone mineral content (BMC) and bone mineral density (BMD) (P < 0.05) than the soccer players on the artificial turf, basketball players on parquet, and handball players on synthetic. In conclusion, a hard playing surface, with less vertical deformation and force reduction, and greater energy return, is associated with higher levels of BMD and BMC in growing girls, regardless of the sport they practice.     

Circadian rhythm effect on physical tennis performance in trained male players

To determine the effect of circadian rhythm on neuromuscular responses and kinematics related to physical tennis performance, after a standardised warm-up, 13 highly competitive male tennis players were tested twice for serve velocity/accuracy (SVA), countermovement vertical jump (CMJ), isometric handgrip strength (IS), agility T-test (AGIL) and a 10-m sprint (10-m RUN). In a randomised, counter-balance order, tennis players underwent the test battery twice, either in the morning (i.e., AM; 9:00 h) and in the afternoon (i.e., PM; 16:30 h). Paired t-tests were used to analyse differences due to time-of-day in performance variables. Comparison of morning versus afternoon testing revealed that SVA (168.5 ± 6.5 vs. 175.2 ± 6.1 km · h^?1; P = 0.003; effect size [ES] = 1.07), CMJ (32.2 ± 0.9 vs. 33.7 ± 1.1 cm; P = 0.018; ES = 1.46), AGIL (10.14 ± 0.1 vs. 9.91 ± 0.2 s; P = 0.007; ES = 1.23) and 10-m RUN time (1.74 ± 0.1 vs. 1.69 ± 0.1 s; P = 0.021; ES = 0.67) were significantly blunted during the morning testing. However, IS was not affected by time-of-day (P = 0.891). Thus, tennis performance may be reduced when competing in the morning in comparison to early evening. Therefore, coaches and tennis players should focus on schedule the SVA, power, speed and agility training sessions in the afternoon.     

Effects of cold water immersion on the recovery of physical performance and muscle damage following a one-off soccer match

The aim of this study was to assess the effects of a single session of cold or thermoneutral water immersion after a one-off match on muscular dysfunction and damage in soccer players. Twenty-male soccer players completed one match and were randomly divided into cryotherapy (10 min cold water immersion, 10°C, n = 10) and thermoneutral (10 min thermoneutral water immersion, 35°C, n = 10) groups. Muscle damage (creatine kinase, myoglobin), inflammation (C-reactive protein), neuromuscular function (jump and sprint abilities and maximal isometric quadriceps strength), and delayed-onset muscle soreness were evaluated before, within 30 min of the end, and 24 and 48 h after the match. After the match, the players in both groups showed increased plasma creatine kinase activity (30 min, 24 h, 48 h), myoglobin (30 min) and C-reactive protein (30 min, 24 h) concentrations. Peak jump ability and maximal strength were decreased and delayed-onset muscle soreness increased in both groups. However, differential alterations were observed between thermoneutral water and cold water immersion groups in creatine kinase (30 min, 24 h, 48 h), myoglobin (30 min), C-reactive protein (30 min, 24 h, 48 h), quadriceps strength (24 h), and quadriceps (24 h), calf (24 h) and adductor (30 min) delayed-onset muscle soreness. The results suggest that cold water immersion immediately after a one-off soccer match reduces muscle damage and discomfort, possibly contributing to a faster recovery of neuromuscular function.     

Physical exercises for preventing injuries among adult male football players: A systematic review

Background:Football is the most practised sport in the world and is associated with the risk of injuries in the players.Some studies have been published that identify injury prevention programs,but there is no review of the full body of evidence on injury prevention programs for use by football coaches.The aim of this article was to carry out a systematic review of published studies on injury prevention programs for adult male footballers,identify points of common understanding and establish recommendations that should be considered in the design of injury prevention strategies.Methods:PubMed and EMBASE databases were used to identify relevant published articles using the following keywords:"soccer"AND"injury"AND"prevention".Results:A total of 2512 studies were identified initially,but only 11 studies met the inclusion criteria,and their outcomes are presented.Results revealed that injury prevention programs in football have focused on strength training,proprioceptive training,multicomponent programs(balance,core stability,and functional strength and mobility),and warm-up programs.Conclusion:Based on results from the studies analyzed,football players can lower the incidence of match and training injuries by participating in dynamic warm-up programs that include preventive exercises before games or during training sessions,and by adding strength,balance,and mobility training to the training sessions.     

The evidence for the impact of policy on physical activity outcomes within the school setting: A systematic review

BackgroundDespite the well-established health benefits of physical activity (PA) for young people (aged 4–19 years), most do not meet PA guidelines. Policies that support PA in schools may be promising, but their impact on PA behavior is poorly understood. The aim of this systematic review was to ascertain the level and type of evidence reported in the international scientific literature for policies within the school setting that contribute directly or indirectly to increasing PA.MethodsThis systematic review is compliant with Preferred Reporting Items for Systematic Review and Meta-Analysis guidelines. Six databases were searched using key concepts of policy, school, evaluation, and PA. Following title and abstract screening of 2323 studies, 25 progressed to data synthesis. Methodological quality was assessed using standardized tools, and the strength of the evidence of policy impact was described based on pre-determined codes: positive, negative, inconclusive, or untested statistically.ResultsEvidence emerged for 9 policy areas that had a direct or indirect effect on PA within the school setting. These were whole school PA policy, physical education, sport/extracurricular PA, classroom-based PA, active breaks/recess, physical environment, shared use agreements, active school transport, and surveillance. The bulk of the evidence was significantly positive (54%), 27% was inconclusive, 9% was significantly negative, and 11% was untested (due to rounding, some numbers add to 99% or 101%). Frequency of evidence was highest in the primary setting (41%), 34% in the secondary setting, and 24% in primary/secondary combined school settings. By policy area, frequency of evidence was highest for sport/extracurricular PA (35%), 17% for physical education, and 12% for whole school PA policy, with evidence for shared use agreements between schools and local communities rarely reported (2%). Comparing relative strength of evidence, the evidence for shared use agreements, though sparse, was 100% positive, while 60% of the evidence for whole school PA policy, 59% of the evidence for sport/extracurricular PA, 57% of the evidence for physical education, 50% of the evidence for PA in classroom, and 50% of the evidence for active breaks/recess were positive.ConclusionThe current evidence base supports the effectiveness of PA policy actions within the school setting but cautions against a “one-size-fits-all” approach and emphasizes the need to examine policy implementation to maximize translation into practice. Greater clarity regarding terminology, measurement, and methods for evaluation of policy interventions is needed.     

Exploring the relationship between hope and burnout in competitive sport

Abstract

Researchers have postulated that hope may be an important factor associated with burnout. Consistent with hope theory contentions, low-hope individuals may be susceptible to burnout because they are prone to experience goal blockage, frustration, and negative affect, all of which likely increase the risk of burnout. We examined the relationship between hope and athlete burnout among 178 competitive athletes (63 females and 115 males) aged 15–20 years. Hope was significantly and negatively correlated with all three burnout subscales: emotional/physical exhaustion, a reduced sense of accomplishment, and sport devaluation. Moreover, results of a multivariate analysis of variance showed that low-hope athletes scored significantly higher than medium- and high-hope athletes on all three burnout dimensions. Finally, results revealed that agency thinking was a significant predictor of all burnout dimensions. Frustration over unmet goals and a perceived lack of agency, a characteristic of low-hope athletes, might pose a risk factor in athlete burnout, whereas being able to maintain hope appears to be associated with health and well-being.     

Variable training: effects on velocity and accuracy in the tennis serve

Abstract

Variable practice has been shown to be an effective strategy to improve open motor skills. However, the usefulness of this procedure in closed motor skills remains controversial. The following study has the objective of analysing the effects of variability practice in the improvement of a closed skill. The skill studied has been the tennis serve. Thirty young tennis players (13 ± 1.52 years), divided in two groups, took part in this study. One group practiced in variable conditions and the other group in consistency conditions. Both groups performed 12 training sessions (60 serves/session). The variable practice group improved their accuracy significantly compared with the consistency group (F_3.25 = 3.078; P = 0.035). The velocity of serve increased after training in both groups (F_3.25 = 15.890; P = 0.001). The practice in variable conditions seems to be effective in improving the performance of the tennis serve.     

Reformation of VET and demands on teachers’ subject knowledge – Swedish vocational teachers’ recurrent participation in a national CPD initiative

This study investigates continuing professional development (CPD) of vocational teachers, with a focus on recurrent participation. Vocational teachers need to be competent as teachers and in relation to their vocational teaching subject. Reformation of Swedish vocational education in order to strengthen the working-life connection imposes demands on teachers to have up-to-date knowledge about the vocations related to their vocational subjects. To support the reform, vocational teachers have been offered to participate in a new national CPD initiative targeting their vocational competence. The study concerns participation in this initiative. Drawing on a socio-cultural perspective, vocational teachers’ CPD implies boundary-crossing between school and working-life. Theory concerning adults’ participation in education is considered relevant to understand conditions for such boundary-crossing, and learning, among vocational teachers. The article specifically investigates patterns in vocational teachers’ recurrent participation, which is expected to clarify the factors influencing further participation in professional development. The strongest predictor of recurrent participation, when adjusting for the influence of other factors, is the type of municipality that the teacher comes from, with low populated municipalities having the lowest likelihood of participation. Furthermore, recurrent participation is more likely by participating teachers from adult education or from privately owned schools, and by male teachers.