Growing up and reaching for the top: A longitudinal study on swim performance and its underlying characteristics in talented swimmers.

The present study strived to gain a more profound understanding of the distinctions in development between swimmers who are considered to be on track to the elite level at late junior age (males aged 16; females aged 15) compared to those who are not. In this effort, swimmers were followed during their pubertal years (males aged 13-15; females aged 12-14), which marks a period when performance development aligns with maturation. Longitudinal data of 90 talented sprint and middle-distance swimmers on season best times (SBT) and underlying performance characteristics (anthropometrics, maximal swimming velocity, stroke index [SI] and countermovement jump [CMJ]) were collected over three swimming seasons. Based on their SBT at late junior age (males aged 16; females aged 15), swimmers were classified as high-performing late juniors or lower-performing late juniors. Retrospectively studying these swimmers, we found that all but two high-performing late juniors were already on track to the elite level at early junior age (males aged 13; females aged 12), evidenced with faster SBT throughout puberty compared to their lower-performing peers (p < 0.05). Independent sample t-tests revealed that high-performing late juniors significantly outscored their lower-performing peers when they were early juniors on maximal swimming velocity (males aged 13-15 and females aged 12-14), SI (males aged 13 and 14; females aged 12), CMJ (females aged 14) and height (females aged 13 and 14, p < 0.05). Additionally, multilevel models showed faster rates of development for high-performing late juniors on maximal swimming velocity (males and females) and SI (males) compared to lower-performing peers throughout puberty (p < 0.05). Higher initial levels of SBT and underlying performance characteristics at early junior age as well as the faster rates of development on SBT, maximal swimming velocity and SI (males only) during the pubertal years, may be crucial factors in maintaining the trajectory towards the elite level after puberty.

Resting state networks mediate the association between both cardiovascular fitness and gross motor skills with neurocognitive functioning.

Recent evidence suggests that cardiovascular fitness and gross motor skill performance are related to neurocognitive functioning by influencing brain structure and functioning. This study investigates the role of resting-state networks (RSNs) in the relation of cardiovascular fitness and gross motor skills with neurocognitive functioning in healthy 8- to 11-year-old children (n = 90, 45 girls, 10% migration background). Cardiovascular fitness and gross motor skills were related to brain activity in RSNs. Furthermore, brain activity in RSNs mediated the relation of both cardiovascular fitness (Frontoparietal network and Somatomotor network) and gross motor skills (Somatomotor network) with neurocognitive functioning. The results indicate that brain functioning may contribute to the relation between both cardiovascular fitness and gross motor skills with neurocognitive functioning.

The relationship between white matter microstructure, cardiovascular fitness, gross motor skills, and neurocognitive functioning in children.

Recent evidence indicates that both cardiovascular fitness and gross motor skill performance are related to enhanced neurocognitive functioning in children by influencing brain structure and functioning. This study investigates the role of white matter microstructure in the relationship of both cardiovascular fitness and gross motor skills with neurocognitive functioning in healthy children. In total 92 children (mean age 9.1 years, range 8.0-10.7) were included in this study. Cardiovascular fitness and gross motor skill performance were assessed using performance-based tests. Neurocognitive functioning was assessed using computerized tests (working memory, inhibition, interference control, information processing, and attention). Diffusion tensor imaging was used in combination with tract-based spatial statistics to assess white matter microstructure as defined by fractional anisotropy (FA), axial and radial diffusivity (AD, RD). The results revealed positive associations of both cardiovascular fitness and gross motor skills with neurocognitive functioning. Information processing and motor response inhibition were associated with FA in a cluster located in the corpus callosum. Within this cluster, higher cardiovascular fitness and better gross motor skills were both associated with greater FA, greater AD, and lower RD. No mediating role was found for FA in the relationship of both cardiovascular fitness and gross motor skills with neurocognitive functioning. The results indicate that cardiovascular fitness and gross motor skills are related to neurocognitive functioning as well as white matter microstructure in children. However, this study provides no evidence for a mediating role of white matter microstructure in these relationships.

Cardiovascular fitness and executive functioning in primary school-aged children.

Previous research in children has shown that higher cardiovascular fitness is related to better executive functioning. However, the available literature is hampered by methodological limitations. The present study investigates the relationship between cardiovascular fitness and executive functioning in a large sample of healthy children (N = 814). Cardiovascular fitness was assessed with estimated VO2Max from 20 m Shuttle Run Test performance. Executive functioning was assessed using a set of computerized neurocognitive tasks aimed at executive functions (working memory, motor inhibition, interference control) and lower-level neurocognitive functions (information processing and attention). Dependent measures derived from the neurocognitive tests were subjected to principal component analysis. Mixed model analyses tested the relation between cardiovascular fitness and neurocognitive functioning components. Results showed that children with higher cardiovascular fitness performed better on the neurocognitive function components Information Processing and Control, Visuospatial Working Memory and Attention Efficiency. The following measures contained in these components contributed to the observed relations: information processing measures, visuospatial working memory, and speed of alerting attention. No relationship was found between cardiovascular fitness and the other components: Verbal Working Memory, Attention Accuracy, and Interference Control. The present study suggests that there is a relationship between cardiovascular fitness and a specific set of executive functions and lower level neurocognitive functions. These findings highlight the importance of cardiovascular fitness for the overall health of school-aged children.

Longitudinal development of 5m sprint performance in young female tennis players.

Sprint performance over short distances is a central component in young tennis players' development. This study aimed to examine the longitudinal development of sprint performance in young female tennis players, and to investigate differences between performance levels. Also potentially explanatory variables were investigated. Female tennis players aged 10-15 (N = 167) participated in a, mixed-longitudinal study (n = 48 elite; n = 119 sub-elite). Players were measured annually on the 5 m sprint as well as for possible explaining variables for 5 m sprint performance development (age, height, body mass, maturity status, lower limb explosive strength). Multilevel analysis was used to obtain a developmental model. Moreover, it was possible to predict sprint performance (5 m) based on chronological age, body size given by height, and lower limb strength performance (p < .05). Significant different developmental patterns were found for elite and sub-elite players, with elite players aged 10-14 being faster. After age 14, no significant differences were found in sprint performance between elite and sub-elite players (p > . 05). Sprint performance is an important characteristic of young female tennis players and seemed to depend on growth and maturation in parallel to physical fitness.

Multigenerational performance development of male and female top-elite swimmers-A global study of the 100 m freestyle event.

BACKGROUND: The present study investigated longitudinally the performance development of a multigenerational sample of competitive swimmers. The aim of the study was to provide unique insight into the junior toward senior performance development of those few who reached top-elite level. Season Best Times (SBT) of 100 m freestyle performance of international swimmers, (1.305 males, aged 12-26 and 1.841 females, aged 12-24) competing in at least five seasons between 1993 and 2018, were corrected for the prevailing world record (WR). Swim performance was defined as a relative measure: relative Season Best Time=(SBT/WR) × 100. Based on rSBT, four performance groups were defined: top-elite, elite, sub-elite, and high-competitive. RESULTS: Univariate analyses of variance showed that male top-elite swimmers outperformed high-competitive swimmers from the age of 12, sub-elite swimmers from the age of 14 and elite swimmers from the age of 18 while female top-elite swimmers outperformed high-competitive and sub-elite swimmers from the age of 12 and elite swimmers from the age of 14 (P < .05). Frequency analysis showed that male top-elite swimmers for the first time achieved top-elite level between the 17 and 24 years old (mean age of 21) while female top-elite swimmers started to perform at top-elite level between the 14 and 24 years old (mean age of 18). CONCLUSION: Male and female top-elite swimmers are characterized by a high-performance level from 12 years on and progressively outperform swimmers from similar age. However, this goes together with a large variety in the individual pathways toward top-elite level within and between sexes.

Effects of aerobic exercise and cognitively engaging exercise on cardiorespiratory fitness and motor skills in primary school children: A cluster randomized controlled trial.

This paper examined effects of two interventions on cardiorespiratory fitness and motor skills, and whether these effects are influenced by baseline levels, and dose of moderate-to-vigorous physical activity (MVPA) during the intervention. A cluster randomized controlled trial was implemented in 22 schools (n = 891; 9.2 ± 07 years). Intervention groups received aerobic or cognitively engaging exercise (14-weeks, four lessons per week). Control groups followed their regular physical education programme. Cardiorespiratory fitness, motor skills and MVPA were assessed. Multilevel analysis showed no main effects on cardiorespiratory fitness and motor skills although the amount of MVPA was higher in the aerobic than in the cognitively engaging and control group. Intervention effects did not depend on baseline cardiorespiratory fitness and motor skills. Children with a higher dose of MVPA within the intervention groups had better cardiorespiratory fitness after both interventions and better motor skills after the cognitively engaging intervention. In conclusion, the interventions were not effective to enhance cardiorespiratory fitness and motor skills at a group level, possibly due to large individual differences and to a total dose of MVPA too low to find effects. However, the amount of MVPA is an important factor that influence the effectiveness of interventions.

Effects of aerobic and cognitively-engaging physical activity on academic skills: A cluster randomized controlled trial.

This cluster randomized controlled trial (trial-number #) compares effects of two school-based physical activity interventions (aerobic vs. cognitively-engaging) on reading, mathematics, and spelling achievement; and whether effects are influenced by volume of moderate-to-vigorous physical activity and baseline achievement. Twenty-two primary schools participated, where a third and fourth grade class were randomly assigned to the intervention or control group. Intervention groups were randomly assigned to a 14-week aerobic or cognitively-engaging intervention, receiving four physical education lessons a week. Control groups followed their regular physical education program. Academic achievement of 891 children (mean age 9.17 years, 49.4% boys) was assessed with standardized tests before and after the interventions. Post-Test academic achievement did not significantly differ between intervention groups and control group. A higher volume of moderate-to-vigorous physical activity resulted in better post-test mathematics achievement in both intervention groups, and post-test spelling achievement in the cognitively engaging intervention group. Compared to the control group, lower achievers in reading performed better in reading after the cognitively-engaging intervention. A combination of moderate-to-vigorous physical activity and cognitively-engaging exercises seems to have the most beneficial effects. Future intervention studies should take into account quantitative and qualitative aspects of physical activity, and children's baseline academic achievement.

The Effects of Aerobic Versus Cognitively Demanding Exercise Interventions on Executive Functioning in School-Aged Children: A Cluster-Randomized Controlled Trial.

The authors performed a clustered randomized controlled trial to investigate the effects of an aerobic and a cognitively demanding exercise intervention on executive functions in primary-school-age children compared with the regular physical education program (N = 856). They hypothesized that both exercise interventions would facilitate executive functioning, with stronger effects for the cognitively demanding exercise group. The interventions were provided four times per week for 14 weeks. Linear mixed models were conducted on posttest neurocognitive function measures with baseline level as covariate. No differences were found between the exercise interventions and the control group for any of the measures. Independently of group, dose of moderate to vigorous physical activity was positively related to verbal working memory and attention abilities. This study showed that physical exercise interventions did not enhance executive functioning in children. Exposure to moderate to vigorous physical activity is a crucial aspect of the relationship between physical activity and executive functioning.

Self-regulatory skills: Are they helpful in the prevention of overuse injuries in talented tennis players?

Talented athletes use metacognitive skills to improve their performance. Also, it is known that these skills are important for managing one's health. The goal of this study was to identify the relationship between metacognitive skills and overuse injuries in talented tennis players. Metacognitive skills were measured in 73 talented tennis players (45 boys and 28 girls, age 11-14) at the start of the season, using the Self-Regulation of Learning Self-Report Scale. Overuse injuries were monitored for one season using the Oslo Sports Trauma Research Centre Questionnaire on Health Problems. Ordinal regression indicated that moderate or low selfmonitoring skills (compared to high selfmonitoring) (OR 4.555, CI 1.096-18.927, P = 0.037) and exposure time (OR 1.380, CI 1.106-1.721, P = 0.004) were associated with more time loss overuse injuries. A second analysis showed that this was the case in girls (OR 10.757, CI 1.845-62.714, P = 0.008), but not in boys. Linear regression revealed that higher reflection scores and exposure time predicted overuse severity (F(5,58) = 2.921, P = 0.020, R2  = 0.201). Possibly, selfmonitoring can help players to prevent themselves from time loss overuse injuries. Coaches should be aware that players can differ in selfmonitoring ability and thus in the ability to prevent overuse injuries. The role of reflection needs more research.

Creating performance benchmarks for the future elites in speed skating.

Sports performance benchmarks useful to select and guide future elites are limited in literature. The present study introduces a method to enable comparison between sports performance of different generations and creates performance benchmarks for the future elites in speed skating. 1500 m Season Best Times (SBT) of Dutch skaters (1043 females, 1812 males, age 13-26 years), who competed in at least six seasons between 1993 and 2013, were corrected for the prevailing world record (WR): rSBT=(SBT/WR)*100%. Regression analyses showed that the calendar year affected SBT (p<0.01), but not rSBT (p>0.05). Based on rSBT, performance groups were defined: elite (rSBT<110%), sub-elite (110%125%). Benchmarks were based on the slowest rSBT per age of the elite group. Of the total skaters performing within the elite benchmarks, the elite performance group represented <20% up to age 16 and <50% up to age 21. An out of sample group (n=299) confirmed the usability of the benchmarks. So, by correcting time-trial performance for the prevailing WR, elite performance benchmarks can be made based on multiple generations of elite skaters. The benchmarks can be used to select and guide future elite skaters from age 13-26 years.

Technical and tactical skills related to performance levels in tennis: A systematic review.

The aim of this systematic review is to provide an overview of outcome measures and instruments identified in the literature for examining technical and tactical skills in tennis related to performance levels. Such instruments can be used to identify talent or the specific skill development training needs of particular players. Searches for this review were conducted using the PubMed, Web of Science, and PsycInfo databases. Out of 733 publications identified through these searches, 40 articles were considered relevant and included in this study. They were divided into three categories: (1) technical skills, (2) tactical skills and (3) integrated technical and tactical skills. There was strong evidence that technical skills (ball velocity and to a lesser extent ball accuracy) and tactical skills (decision making, anticipation, tactical knowledge and visual search strategies) differed among players according to their performance levels. However, integrated measurement of these skills is required, because winning a point largely hinges on a tactical decision to perform a particular stroke (i.e., technical execution). Therefore, future research should focus on examining the relationship between these skills and tennis performance and on the development of integrated methods for measuring these skills.

The importance and development of ball control and (self-reported) self-regulatory skills in basketball players for different positions.

This study first investigated the importance of ball control and (self-reported) self-regulatory skills in achieving the elite level in basketball. The second aim was to gain insight into the development of, and association between ball control and (self-reported) self-regulatory skills that contribute to achieving the elite level, with taking into account positional differences. Talented male players (N = 73; age 16.56 ± 1.96) completed the STARtest to measure ball control and a questionnaire to measure (self-reported) self-regulation from 2008-2012. Results showed that (self-reported) reflective skills were most important to achieve the elite level (OR = 11.76; P < 0.05). There was no significant improvement in (self-reported) reflection over time for guards, forwards, and centers. Improvement in ball control was evident for guards (r = -0.65; P < 0.05). Furthermore, guards and forwards had better ball control compared to centers (P < 0.01). For those two positions, negative correlations were found between (self-reported) reflection and ball control, i.e., higher reflection was related to better ball control (guards r = -0.19; forwards r = -0.18) in contrast to centers (r = 0.34). It is concluded that (self-reported) reflective skills are important to achieve the elite level, while ball control seems especially important for guards.

Injury Risk Is Increased by Changes in Perceived Recovery of Team Sport Players.

OBJECTIVE: The aim of this study is to investigate if changes in perceived stress and recovery over the course of a season are risk factors for acute and overuse injuries. DESIGN: A prospective nonexperimental cohort design. SETTING: Data were gathered at the SportsFieldLab Groningen and at the facilities of the participating teams. PARTICIPANTS: Eighty-six male and female basketball, volleyball, and korfball players aged 21.9 ± 3.5 years. INTERVENTIONS: In this 10-month observational study, the independent variables are the changes in perceived stress and recovery. MAIN OUTCOME MEASURES: The Recovery-Stress Questionnaire for Athletes (RESTQ-Sport) was filled out every 3 weeks throughout the season to assess changes in perceived stress and recovery. Acute and overuse injuries were registered by the teams' physical therapists. Odds ratios and 95% confidence intervals were calculated. RESULTS: During one season, 66 acute and 62 overuse injuries were registered. Multinomial regression analysis showed that perceived General Recovery, shown in the scales Social Recovery and General Well-Being, decreased in the 6-week period before an acute injury (OR 0.59 and 0.61, respectively, P ≤ 0.05) compared with healthy periods. Risk of overuse injuries increased when perceived Sport Recovery, shown in the Personal Accomplishment scale, decreased in the 3-week period before the injury (OR 0.59, P ≤ 0.05) compared with healthy periods. CONCLUSIONS: Therefore, decreased perceived recovery can indicate an increased injury risk. General Recovery affects acute injury risk and Sport Recovery affects the risk of an overuse injury. Monitoring perceived recovery over the course of a season could give guidance for recovery enhancing practices to prevent injuries.

Laterality related to the successive selection of Dutch national youth soccer players.

In the general population, estimates of left-foot preference are around 20%. In soccer, specific tasks create positional demands, requiring 40% of the players to be left-footed. Whether and how this is related to the selection of players is unknown. To examine the successive selection of soccer players for Dutch national youth teams in relation to foot preference, 280 youth players (age = 16.2 ± 1.08 years) were monitored from the U16 through the U19 teams over the last 5 years. No difference in successive selection between left- and right-footed players was found (p < 0.05). Regardless of foot preference, more than 50% of the selected players were deselected out of a national youth team after 2 years. On average, 31% of the national youth players were left-footed, which is higher than expected, based on population estimates (χ2 (1) = 37.49, p < 0.001, w = 0.27). However, there was an under-representation of left-footed players, based on expected positional demands (i.e., attack, midfield, defence) (χ2 (1) = 16.83, p < 0.001, w = 0.18). The conclusion is that left-foot preference increases the probability of selection in Dutch national youth soccer teams.

Prediction of Tennis Performance in Junior Elite Tennis Players.

Predicting current and future tennis performance can lead to improving the development of junior tennis players. The aim of this study is to investigate whether age, maturation, or physical fitness in junior elite tennis players in U13 can explain current and future tennis performance. The value of current tennis performance for future tennis performance is also investigated. A total of 86 junior elite tennis players (boys, n = 44; girls, n = 42) U13 (aged: 12.5 ± 0.3 years), and followed to U16, took part in this study. All players were top-30 ranked on the Dutch national ranking list at U13, and top-50 at U16. Age, maturation, and physical fitness, were measured at U13. A principal component analysis was used to extract four physical components from eight tests (medicine ball throwing overhead and reverse, ball throwing, SJ, CMJas, Sprint 5 and 10 meter, and the spider test). The possible relationship of age, maturation, and the physical components; "upper body power", "lower body power", "speed", and "agility" with tennis performance at U13 and U16 was analyzed. Tennis performance was measured by using the ranking position on the Dutch national ranking list at U13 and U16. Regression analyses were conducted based on correlations between variables and tennis performance for boys and girls, separately. In boys U13, positive correlations were found between upper body power and tennis performance (R2 is 25%). In girls, positive correlations between maturation and lower body power with tennis performance were found at U13. Early maturing players were associated with a better tennis performance (R2 is 15%). In girls U16, only maturation correlated with tennis performance (R2 is 13%); later-maturing girls at U13 had better tennis performances at U16. Measuring junior elite tennis players at U13 is important for monitoring their development. These measurements did not predict future tennis performance of junior elite tennis players three years later. Future research should focus on other aspects in order to predict tennis performance better.

The development of self-regulated learning during the pre-clinical stage of medical school: a comparison between a lecture-based and a problem-based curriculum.

Society expects physicians to always improve their competencies and to be up to date with developments in their field. Therefore, an important aim of medical schools is to educate future medical doctors to become self-regulated, lifelong learners. However, it is unclear if medical students become better self-regulated learners during the pre-clinical stage of medical school, and whether students develop self-regulated learning skills differently, dependent on the educational approach of their medical school. In a cross-sectional design, we investigated the development of 384 medical students' self-regulated learning skills with the use of the Self-Regulation of Learning Self-Report Scale. Next, we compared this development in students who enrolled in two distinct medical curricula: a problem-based curriculum and a lectured-based curriculum. Analysis showed that more skills decreased than increased during the pre-clinical stage of medical school, and that the difference between the curricula was mainly caused by a decrease in the skill evaluation in the lecture-based curriculum. These findings seem to suggest that, irrespective of the curriculum, self-regulated learning skills do not develop during medical school.

Self-regulated learning and academic performance in medical education.

CONTENT: Medical schools aim to graduate medical doctors who are able to self-regulate their learning. It is therefore important to investigate whether medical students' self-regulated learning skills change during medical school. In addition, since these skills are expected to be helpful to learn more effectively, it is of interest to investigate whether these skills are related to academic performance. METHODS: In a cross-sectional design, the Self-Regulation of Learning Self-Report Scale (SRL-SRS) was used to investigate the change in students' self-regulated learning skills. First and third-year students (N = 949, 81.7%) SRL-SRS scores were compared with ANOVA. The relation with academic performance was investigated with multinomial regression analysis. RESULTS: Only one of the six skills, reflection, significantly, but positively, changed during medical school. In addition, a small, but positive relation of monitoring, reflection, and effort with first-year GPA was found, while only effort was related to third-year GPA. CONCLUSIONS: The change in self-regulated learning skills is minor as only the level of reflection differs between the first and third year. In addition, the relation between self-regulated learning skills and academic performance is limited. Medical schools are therefore encouraged to re-examine the curriculum and methods they use to enhance their students' self-regulated learning skills. Future research is required to understand the limited impact on performance.

A Longitudinal Study of Physical Fitness in Elite Junior Tennis Players.

PURPOSE: To analyze how physical fitness (PF) improves in elite junior tennis players related to age, maturity, and performance level. METHODS: Elite junior tennis players (n = 113 boys, n = 83 girls) divided by performance level were monitored longitudinally from U14 to U16. Maturity, upper and lower-body power, speed, and agility were measured during subsequent competitive seasons. Improvement was analyzed per sex using multilevel analysis. RESULTS: PF components for boys and girls improved over age (U14-U16) (ES .53-.97). In boys, the more mature boys outscored the less mature boys in upper and lower-body power from U14-U16. In girls, high-ranked girls outscored lower-ranked girls on lower-body power, speed, and agility (U14-U16) (p < .05). CONCLUSION: Boys and girls improved on all PF components during U14-U16. In boys, power was related to maturity. In girls, lower-body power, speed, and agility were related to tennis performance. This has important implications for talent development.

Effects of a Cognitively Demanding Aerobic Intervention During Recess on Children's Physical Fitness and Executive Functioning.

The objective of this study was to analyze the effects of a physical activity program including both aerobic exercise and cognitively engaging physical activities on children's physical fitness and executive functions. Children from 3 primary schools (aged 8-12 years) were recruited. A quasi-experimental design was used. Children in the intervention group (n = 53; 19 boys, 34 girls) participated in a 22-week physical activity program for 30 min during lunch recess, twice a week. Children in the control group (n = 52; 32 boys, 20 girls) followed their normal lunch routine. Aerobic fitness, speed and agility, and muscle strength were assessed using the Eurofit test battery. Executive functions were assessed using tasks measuring inhibition (Stroop test), working memory (Visual Memory Span test, Digit Span test), cognitive flexibility (Trailmaking test), and planning (Tower of London). Children in the intervention group showed significantly greater improvement than children in the control group on the Stroop test and Digit Span test, reflecting enhanced inhibition and verbal working memory skills, respectively. No differences were found on any of the physical fitness variables. A physical activity program including aerobic exercise and cognitively engaging physical activities can enhance aspects of executive functioning in primary school children.