Resolving the Centipede's Dilemma: external focus distance and expertise in applied, continuous skills.

Research has reliably demonstrated that an external focus of attention during skill production enhances performance, retention, and transfer relative to an internal focus on movement mechanics. The optimisation of external focus points, across a range of contexts and performers, is important for effective skill production. Two studies were conducted evaluating the impact of external focus distance in an applied, continuous sports skill (kayak sprinting) with participants of two different expertise levels. In Study 1, using a within-participants design, recreational kayakers (n = 20) were timed sprinting 75 m in a surf ski under proximal external focus, distal external focus, and control conditions. The distal focus (on the finish) (29.75 s) was significantly faster than both other trials (ps < 0.001). The control condition (30.95 s) was significantly faster than the proximal focus (on the boat) (32.37 s) (p = 0.003). The effect size was large (ηp2 = 0.55). In Study 2, specifically trained racers in sprint kayaks (K1s) (n = 16) were timed in a 100 m K1 sprint under the same three conditions as in Study 1. The control condition (28.96 s) was significantly faster than the proximal focus trial (29.83 s) (p = 0.02). The effect size was large (ηp2 = 0.23). There was no significant difference between the distal focus trial (29.03 s) and the other conditions. These findings suggest that focus distance can play a pivotal role in continuous skills. Whilst recreational performers may benefit immediately from a distal focus, this might not be the case for specifically trained athletes. Further, a proximal focus on fitted, passive equipment may be detrimental to performance.

The impact of sprint, middle-distance, and long-distance orienteering races on perceived mental fatigue in national level orienteers.

Experiencing mental fatigue (MF) before an orienteering race can lead to a slower completion time. This study aimed to explore the changes in perceived MF, mood and other psychological responses during an orienteering competition. Sixteen national level orienteering athletes (20.8 ± 4.9 years) provided informed consent and completed the online surveys, before and immediately after each race, and 24- and 48-hours post competition (48POST). This study measured MF, physical fatigue, stress, tiredness and motivation using 0-100 Visual Analogue Scale, and the mood was assessed using The Brunel Mood Scale (BRUMS). A moderate to large increase in MF (ES = 0.93 [0.54 to 1.31]), BRUMS fatigue (ES = 0.61 [0.3 to 0.92]), and PF (ES = 1.21 [0.81 to 1.61]) was reported following orienteering races. A small increase in tiredness and BRUMS confusion, and a small decrease in motivation, stress and BRUMS vigour was also reported. There was a delay in recovering from the MF elicited by competition, with a small increase in MF (ES = 0.54 [0.08 to 1.15]) at 48POST compared to the pre-competition value. This study found that orienteers experience MF during competition and have a delayed recovery that can last up to two days after the competition.

Circadian preference and physical and cognitive performance in adolescence: A scoping review.

Adolescence is a crucial period of development which coincides with changes in circadian rhythmicity. This may augment the impact of circadian preference on performance in this group. We aimed to scope the literature available on chronotypes and their effect on physical and mental aspects of performance in adolescents. Studies were identified by systematically searching bibliographical databases and grey literature. The Morningness-Eveningness Questionnaire was the most frequently reported tool for circadian preference assessment. Academic achievement was the most prevailing outcome, with evidence suggesting that morning type adolescents tend to outperform evening types, yet the results vary depending on multiple factors. Performance in tests of intelligence and executive functions was generally better at optimal times of the day (synchrony effect). Physical performance was examined in 8 studies, with very heterogeneous outcomes. Although the associations between circadian preference and performance in adolescents are evident in some areas, there are many factors that may be involved in the relationship and require further investigation. This review highlights the assessment of physical performance in relation to chronotypes, the multidimensional assessment of circadian preference, and the need for longitudinal studies as priorities for further research.Protocol: OSF Registration - Public registration, DOI: 10.17605/OSF.IO/UCA3Z.

The Effect of Unilateral and Bilateral Leg Press Training on Lower Body Strength and Power and Athletic Performance in Adolescent Rugby Players.

This study aimed to compare the effects of 5 weeks of unilateral and bilateral leg press training on lower body strength, linear sprinting and vertical jumping performance in adolescent rugby players. Twenty-six male adolescent rugby players (age = 15.3 ± 0.4 years) were assigned via stratified block randomization to unilateral (n = 9), bilateral (n = 9) and control (n = 8) groups. Training consisted of either the unilateral or the bilateral leg press twice weekly over five weeks, with the control group maintaining habitual training. Lower body unilateral and bilateral strength, vertical jump and linear sprint performance were assessed before and after training. After 5 weeks of training, both training groups significantly increased the 5-repetition maximum bilateral leg press (unilateral group = 8.9%, d = 0.53; bilateral group = 10.9%, d = 0.55, p < 0.01) and the 5-repetition maximum unilateral leg press (unilateral group = 20.2%, d = 0.81; bilateral group = 12.4%, d = 0.45, p < 0.01). There was no significant difference between the size of improvement in unilateral and bilateral groups in the 5-repetition maximum bilateral leg press, but the 5-repetition maximum unilateral leg press increased significantly more in the unilateral group (p < 0.05). No significant training effects were found for vertical jump or linear sprint performance. The results indicated that unilateral leg press training was as effective as bilateral leg press training in improving bilateral strength and more effective in improving unilateral strength in adolescent rugby players. However, strength improvement did not transfer to athletic performance improvements in either group.

Hypermobility prevalence, measurements, and outcomes in childhood, adolescence, and emerging adulthood: a systematic review.

General Joint Hypermobility (GJH) is a common condition found in 2-57% of the population. Of those with GJH, 10% suffer from accompanying physical and/or psychological symptoms. While the understanding of GJH in the general population is unfolding, its implication in a cohort of children, adolescents and young adults are not yet understood. This systematic review explored GJH's prevalence, tools to measure it, its physical and psychosocial symptoms, with a special interest in aesthetic sports. The CINHAL, MEDLINE, PsycINFO, SPORTDiscus and Scopus databases were searched for relevant studies. Inclusion criteria were (1) Age range of 5-24; (2) Participants had GJH; (3) A measurement for GJH; (4) Studies written in English language. Study screening for title, abstract and full text (when needed) and quality assessment were performed by two independent individuals. 107 studies were included in this review and were thematically grouped into six clusters expressing different foci: (1) GJH's Core Characteristics; (2) Orthopedic; (3) Physical Other; (4) Psychosocial; (5) Treatment and (6) Aesthetic Sports. The review revealed a growing interest in GJH in this cohort in the last decade, especially regarding non-musculoskeletal physical implications and psychosocial aspects. Prevalence varied between different ethnic groups and as a parameter of age, gender and measurement. The most widespread tool to measure GJH was the Beighton scale, with a cut-off varying between 4 and 7. Children show fewer, but similar GJH implication to those in the general population, however, more research on the topic is warranted, especially regarding psychosocial aspects and treatment.

International orienteering experts' consensus on the definition, development, cause, impact and methods to reduce mental fatigue in orienteering: A Delphi study.

Orienteering is an outdoor activity wherein participants use a map and compass to locate control points and choose the quickest path to the next control point in a natural environment. Attentional focus, rapid decision-making, and high aerobic fitness may influence orienteering performance. Therefore, this research aimed to seek international orienteering expert consensus regarding the definition, development, causes, influences and methods to reduce mental fatigue (MF) in orienteering based on practical experience. Following ethical approval, a three-round Delphi survey was conducted online with twenty-four orienteering coaches and athletes (or former athletes) from 10 different countries with international orienteering competition experience. The threshold of consensus was ≥ 70% agreement among respondents. The experts agreed that MF exists in daily life and orienteering with a substantial negative effect on their conscious decision-making performance and psychological responses. The experts disagreed that the form of MF that athletes experienced in orienteering training are similar to the competition. However, there was no agreement that MF would impact endurance and high-speed running performance during orienteering. This research refines the definition of MF and summarises the distinctions in what causes MF in orienteering training and competition, implying that MF should be addressed separately.

A Concussion Education Programme for Motorsport Drivers: A Field-Based Exploratory Pilot Study.

OBJECTIVE: Concussion education strategies that improve knowledge and attitudes long term are needed. This exploratory study piloted an interactive concussion education program, adopting concepts from the learning sciences and attitude change literature, for the underserved and high-risk population of motorsports. METHOD: Forty UK motorsport drivers (ages 16-20 years) participated. The workshop group received a two-phased workshop-based program. The comparison group received a concussion leaflet. Participants completed an adapted version of the Rosenbaum Concussion Knowledge and Attitudes Survey (RoCKAS-ST) at pre-, post- and 2-month follow-up. Within-group analysis for the workshop group explored the differential effect of the individual difference variable, Need for Cognition (NfC), and effectiveness was explored through post-workshop questionnaires and interviews. RESULTS: Unlike the comparison group, the workshop group showed a significant improvement in knowledge over time (F(2,58) = 45.49, p < .001, η2p = .61). Qualitative data indicated workshop-program participants developed safer attitudes toward concussion following programming. Preliminary evidence suggested individuals' responses to concussion education aligned with differences in NfC. CONCLUSION: This study piloted the first concussion education program for motorsport drivers and explored whether aligning educational provision with the NfC construct may help to improve program effectiveness. Findings are relevant to addressing the public health issue of concussion through educational approaches.

Forward thinking: When a distal external focus makes you faster.

Studies have demonstrated a benefit to performance and learning of a distal relative to a proximal external focus of attention. That is, focusing on a movement effect that occurs at a greater distance from the body has been found to be more effective than concentrating on a movement effect closer to the body. The present study examined the distance effect in skilled kayakers performing an open, continuous skill. Participants (n = 27) performed a wild water racing sprint of 100 m on Class 2 water. Using a within-participants design, a distal external focus ("Focus on the finish") was compared to a proximal external focus ("Focus on the paddle") as well as to a control condition. The distal focus condition (30.63 s, SD = 3.21) resulted in significantly shorter sprint times than did the proximal (32.07 s, SD = 3.27) and the control (31.96 s, SD = 3.58) conditions (ps < 0.001). The effect size was large (ηp2 = 0.53). There was no significant difference between the proximal and control condition (p = 1.00). The findings demonstrate the importance of adopting a distal, rather than proximal, external focus for skilled athletes performing open, continuous skills under time pressure.

Variability of within-step acceleration and daily wellness monitoring in Collegiate American Football.

OBJECTIVES: It is commonplace to consider accelerometer load and any resultant neuromuscular fatigue in training programs. With these data becoming accepted in sport alongside wellness questionnaires this study aimed to investigate if a deeper analysis of the accelerometry data can provide actionable insight into training-induced disruptions. DESIGN: Accelerometer data from Collegiate American Football athletes (n=63) were collected during training and matches across a regular season. METHODS: These data were processed to: identify instances of high speed running, extract step waveforms from those sections, and determine the variability of those waveforms via a within- and between-section co-efficient of multiple determination. Athletes completed wellness questionnaires prior to sessions that were used to flag areas of muscle soreness as well as fatigue, or disturbed sleep quality. Linear mixed models were used to assess associations between inter stride variability and flags in wellness/soreness markers. RESULTS: An increase in acute (7d) load saw an increased stride variability in these athletes. Feeling less fatigued and/or lower muscle soreness was associated with higher stride variability. CONCLUSIONS: The assessment of variability has the potential to identify athletes who are displaying physical symptoms that would indicate the need to modify training.

Effect of Skilled Dancers' Focus of Attention on Pirouette Performance.

Extant attentional focus research has largely examined movement tasks that are outcome-focused (e.g., height of jumps, force production, and number of successful turns) with fewer studies of the movement quality or form of an aesthetic discipline (e.g., dance, gymnastics, and ice-skating). In this study, both movement form and outcomebased measures were used to assess the performance of a pirouette. Thirteen skilled dancers performed pirouettes on a force plate under three trial conditions: control (no focus instruction), external focus instruction, and internal focus instruction. Assessment of the dancers' performance was quantified by 1. variability of postural sway, 2. duration of balance sustained, and 3. quality of movement form as rated by four experienced dance teachers. To corroborate the quantitative findings, dancers' perspectives were included in the study. Statistical analysis showed that the quality of a pirouette under the influence of external or internal focus instructions did not differ in any of the measured dependent variables. However, when the results were interpreted in the context of participants' perspective, there was a perceived improvement with either the prescribed external or internal focus over the control condition.

Recovery practices in Division 1 collegiate athletes in North America.

OBJECTIVES: Establish current practice and attitudes towards recovery in a group of Division-1 Collegiate athletes from North America. DESIGN: A 16-item questionnaire was administered via custom software in an electronic format. PARTICIPANTS: 152 student athletes from a Division-1 Collegiate school across 3 sports (Basketball, American Football, Soccer). MAIN OUTCOME MEASURES: The approaches and attitudes to recovery in both training and competition. RESULTS: Sleep, cold water immersion (CWI) and nutrition were perceived to be the most effective modalities (88, 84 and 80% of the sample believed them to have a benefit respectively). Over half the sample did not believe in using compression for recovery. With regard to actual usage, CWI was the most used recovery modality and matched by athletes believing in, and using, the approach (65%). Only 24% of student athletes believed in, and used, sleep as a recovery modality despite it being rated and perceived as the most effective. CONCLUSIONS: Collectively, there is a discrepancy between perception and use of recovery modalities in Collegiate athletes.

Physical activity, diet and other behavioural interventions for improving cognition and school achievement in children and adolescents with obesity or overweight.

BACKGROUND: The global prevalence of childhood and adolescent obesity is high. Lifestyle changes towards a healthy diet, increased physical activity and reduced sedentary activities are recommended to prevent and treat obesity. Evidence suggests that changing these health behaviours can benefit cognitive function and school achievement in children and adolescents in general. There are various theoretical mechanisms that suggest that children and adolescents with excessive body fat may benefit particularly from these interventions. OBJECTIVES: To assess whether lifestyle interventions (in the areas of diet, physical activity, sedentary behaviour and behavioural therapy) improve school achievement, cognitive function (e.g. executive functions) and/or future success in children and adolescents with obesity or overweight, compared with standard care, waiting-list control, no treatment, or an attention placebo control group. SEARCH METHODS: In February 2017, we searched CENTRAL, MEDLINE and 15 other databases. We also searched two trials registries, reference lists, and handsearched one journal from inception. We also contacted researchers in the field to obtain unpublished data. SELECTION CRITERIA: We included randomised and quasi-randomised controlled trials (RCTs) of behavioural interventions for weight management in children and adolescents with obesity or overweight. We excluded studies in children and adolescents with medical conditions known to affect weight status, school achievement and cognitive function. We also excluded self- and parent-reported outcomes. DATA COLLECTION AND ANALYSIS: Four review authors independently selected studies for inclusion. Two review authors extracted data, assessed quality and risks of bias, and evaluated the quality of the evidence using the GRADE approach. We contacted study authors to obtain additional information. We used standard methodological procedures expected by Cochrane. Where the same outcome was assessed across different intervention types, we reported standardised effect sizes for findings from single-study and multiple-study analyses to allow comparison of intervention effects across intervention types. To ease interpretation of the effect size, we also reported the mean difference of effect sizes for single-study outcomes. MAIN RESULTS: We included 18 studies (59 records) of 2384 children and adolescents with obesity or overweight. Eight studies delivered physical activity interventions, seven studies combined physical activity programmes with healthy lifestyle education, and three studies delivered dietary interventions. We included five RCTs and 13 cluster-RCTs. The studies took place in 10 different countries. Two were carried out in children attending preschool, 11 were conducted in primary/elementary school-aged children, four studies were aimed at adolescents attending secondary/high school and one study included primary/elementary and secondary/high school-aged children. The number of studies included for each outcome was low, with up to only three studies per outcome. The quality of evidence ranged from high to very low and 17 studies had a high risk of bias for at least one item. None of the studies reported data on additional educational support needs and adverse events.Compared to standard practice, analyses of physical activity-only interventions suggested high-quality evidence for improved mean cognitive executive function scores. The mean difference (MD) was 5.00 scale points higher in an after-school exercise group compared to standard practice (95% confidence interval (CI) 0.68 to 9.32; scale mean 100, standard deviation 15; 116 children, 1 study). There was no statistically significant beneficial effect in favour of the intervention for mathematics, reading, or inhibition control. The standardised mean difference (SMD) for mathematics was 0.49 (95% CI -0.04 to 1.01; 2 studies, 255 children, moderate-quality evidence) and for reading was 0.10 (95% CI -0.30 to 0.49; 2 studies, 308 children, moderate-quality evidence). The MD for inhibition control was -1.55 scale points (95% CI -5.85 to 2.75; scale range 0 to 100; SMD -0.15, 95% CI -0.58 to 0.28; 1 study, 84 children, very low-quality evidence). No data were available for average achievement across subjects taught at school.There was no evidence of a beneficial effect of physical activity interventions combined with healthy lifestyle education on average achievement across subjects taught at school, mathematics achievement, reading achievement or inhibition control. The MD for average achievement across subjects taught at school was 6.37 points lower in the intervention group compared to standard practice (95% CI -36.83 to 24.09; scale mean 500, scale SD 70; SMD -0.18, 95% CI -0.93 to 0.58; 1 study, 31 children, low-quality evidence). The effect estimate for mathematics achievement was SMD 0.02 (95% CI -0.19 to 0.22; 3 studies, 384 children, very low-quality evidence), for reading achievement SMD 0.00 (95% CI -0.24 to 0.24; 2 studies, 284 children, low-quality evidence), and for inhibition control SMD -0.67 (95% CI -1.50 to 0.16; 2 studies, 110 children, very low-quality evidence). No data were available for the effect of combined physical activity and healthy lifestyle education on cognitive executive functions.There was a moderate difference in the average achievement across subjects taught at school favouring interventions targeting the improvement of the school food environment compared to standard practice in adolescents with obesity (SMD 0.46, 95% CI 0.25 to 0.66; 2 studies, 382 adolescents, low-quality evidence), but not with overweight. Replacing packed school lunch with a nutrient-rich diet in addition to nutrition education did not improve mathematics (MD -2.18, 95% CI -5.83 to 1.47; scale range 0 to 69; SMD -0.26, 95% CI -0.72 to 0.20; 1 study, 76 children, low-quality evidence) and reading achievement (MD 1.17, 95% CI -4.40 to 6.73; scale range 0 to 108; SMD 0.13, 95% CI -0.35 to 0.61; 1 study, 67 children, low-quality evidence). AUTHORS' CONCLUSIONS: Despite the large number of childhood and adolescent obesity treatment trials, we were only able to partially assess the impact of obesity treatment interventions on school achievement and cognitive abilities. School and community-based physical activity interventions as part of an obesity prevention or treatment programme can benefit executive functions of children with obesity or overweight specifically. Similarly, school-based dietary interventions may benefit general school achievement in children with obesity. These findings might assist health and education practitioners to make decisions related to promoting physical activity and healthy eating in schools. Future obesity treatment and prevention studies in clinical, school and community settings should consider assessing academic and cognitive as well as physical outcomes.

Physical activity, diet and other behavioural interventions for improving cognition and school achievement in children and adolescents with obesity or overweight.

BACKGROUND: The global prevalence of childhood and adolescent obesity is high. Lifestyle changes towards a healthy diet, increased physical activity and reduced sedentary activities are recommended to prevent and treat obesity. Evidence suggests that changing these health behaviours can benefit cognitive function and school achievement in children and adolescents in general. There are various theoretical mechanisms that suggest that children and adolescents with excessive body fat may benefit particularly from these interventions. OBJECTIVES: To assess whether lifestyle interventions (in the areas of diet, physical activity, sedentary behaviour and behavioural therapy) improve school achievement, cognitive function (e.g. executive functions) and/or future success in children and adolescents with obesity or overweight, compared with standard care, waiting-list control, no treatment, or an attention placebo control group. SEARCH METHODS: In February 2017, we searched CENTRAL, MEDLINE and 15 other databases. We also searched two trials registries, reference lists, and handsearched one journal from inception. We also contacted researchers in the field to obtain unpublished data. SELECTION CRITERIA: We included randomised and quasi-randomised controlled trials (RCTs) of behavioural interventions for weight management in children and adolescents with obesity or overweight. We excluded studies in children and adolescents with medical conditions known to affect weight status, school achievement and cognitive function. We also excluded self- and parent-reported outcomes. DATA COLLECTION AND ANALYSIS: Four review authors independently selected studies for inclusion. Two review authors extracted data, assessed quality and risks of bias, and evaluated the quality of the evidence using the GRADE approach. We contacted study authors to obtain additional information. We used standard methodological procedures expected by Cochrane. Where the same outcome was assessed across different intervention types, we reported standardised effect sizes for findings from single-study and multiple-study analyses to allow comparison of intervention effects across intervention types. To ease interpretation of the effect size, we also reported the mean difference of effect sizes for single-study outcomes. MAIN RESULTS: We included 18 studies (59 records) of 2384 children and adolescents with obesity or overweight. Eight studies delivered physical activity interventions, seven studies combined physical activity programmes with healthy lifestyle education, and three studies delivered dietary interventions. We included five RCTs and 13 cluster-RCTs. The studies took place in 10 different countries. Two were carried out in children attending preschool, 11 were conducted in primary/elementary school-aged children, four studies were aimed at adolescents attending secondary/high school and one study included primary/elementary and secondary/high school-aged children. The number of studies included for each outcome was low, with up to only three studies per outcome. The quality of evidence ranged from high to very low and 17 studies had a high risk of bias for at least one item. None of the studies reported data on additional educational support needs and adverse events.Compared to standard practice, analyses of physical activity-only interventions suggested high-quality evidence for improved mean cognitive executive function scores. The mean difference (MD) was 5.00 scale points higher in an after-school exercise group compared to standard practice (95% confidence interval (CI) 0.68 to 9.32; scale mean 100, standard deviation 15; 116 children, 1 study). There was no statistically significant beneficial effect in favour of the intervention for mathematics, reading, or inhibition control. The standardised mean difference (SMD) for mathematics was 0.49 (95% CI -0.04 to 1.01; 2 studies, 255 children, moderate-quality evidence) and for reading was 0.10 (95% CI -0.30 to 0.49; 2 studies, 308 children, moderate-quality evidence). The MD for inhibition control was -1.55 scale points (95% CI -5.85 to 2.75; scale range 0 to 100; SMD -0.15, 95% CI -0.58 to 0.28; 1 study, 84 children, very low-quality evidence). No data were available for average achievement across subjects taught at school.There was no evidence of a beneficial effect of physical activity interventions combined with healthy lifestyle education on average achievement across subjects taught at school, mathematics achievement, reading achievement or inhibition control. The MD for average achievement across subjects taught at school was 6.37 points lower in the intervention group compared to standard practice (95% CI -36.83 to 24.09; scale mean 500, scale SD 70; SMD -0.18, 95% CI -0.93 to 0.58; 1 study, 31 children, low-quality evidence). The effect estimate for mathematics achievement was SMD 0.02 (95% CI -0.19 to 0.22; 3 studies, 384 children, very low-quality evidence), for reading achievement SMD 0.00 (95% CI -0.24 to 0.24; 2 studies, 284 children, low-quality evidence), and for inhibition control SMD -0.67 (95% CI -1.50 to 0.16; 2 studies, 110 children, very low-quality evidence). No data were available for the effect of combined physical activity and healthy lifestyle education on cognitive executive functions.There was a moderate difference in the average achievement across subjects taught at school favouring interventions targeting the improvement of the school food environment compared to standard practice in adolescents with obesity (SMD 0.46, 95% CI 0.25 to 0.66; 2 studies, 382 adolescents, low-quality evidence), but not with overweight. Replacing packed school lunch with a nutrient-rich diet in addition to nutrition education did not improve mathematics (MD -2.18, 95% CI -5.83 to 1.47; scale range 0 to 69; SMD -0.26, 95% CI -0.72 to 0.20; 1 study, 76 children, low-quality evidence) and reading achievement (MD 1.17, 95% CI -4.40 to 6.73; scale range 0 to 108; SMD 0.13, 95% CI -0.35 to 0.61; 1 study, 67 children, low-quality evidence). AUTHORS' CONCLUSIONS: Despite the large number of childhood and adolescent obesity treatment trials, we were only able to partially assess the impact of obesity treatment interventions on school achievement and cognitive abilities. School and community-based physical activity interventions as part of an obesity prevention or treatment programme can benefit executive functions of children with obesity or overweight specifically. Similarly, school-based dietary interventions may benefit general school achievement in children with obesity. These findings might assist health and education practitioners to make decisions related to promoting physical activity and healthy eating in schools. Future obesity treatment and prevention studies in clinical, school and community settings should consider assessing academic and cognitive as well as physical outcomes.

Longitudinal Associations Between Childhood Obesity and Academic Achievement: Systematic Review with Focus Group Data.

PURPOSE: The purposes of this study were to review the evidence on longitudinal associations between child and adolescent obesity and academic achievement and to provide perceptions of adolescents with obesity and their parents on this topic. RECENT FINDINGS: Synthesis of 31 studies (from 17 cohorts) suggested that relationships between obesity and academic achievement are not well established, except for adolescent girls' maths attainment, potentially mediated by both weight-related bullying and executive cognitive functions. Focus groups with adolescent girls with obesity confirmed experiences of psychosocial distress at school particularly during Physical Education. Adolescents perceived that obesity was not related to academic achievement directly, but by their attitude to school. Interventions are warranted to promote psychosocial wellbeing and cognitive abilities linked to academic achievement in adolescent girls with obesity. Physical Education should be a positive experience for children and adolescents with obesity.

Practices & attitudes towards recovery in elite Asian & UK adolescent athletes.

OBJECTIVES: Assess current practice and attitudes towards recovery in adolescent athletes. DESIGN: Questionnaires were administered either via print or online questionnaire. PARTICIPANTS: Athletes and coaches from within Asia were surveyed (n = 112 & 53), with a comparative sample in the UK (n = 53 & 8). MAIN OUTCOME MEASURES: The approaches and attitudes to recovery in both training and competition. RESULTS: Adolescent athletes perceive a variety of recovery modalities as important, though prioritise active recovery, nutrition and sleep. Attitudes towards recovery differed between athletes in Asia and the UK with respect to the perceived benefits of: sleep (96% believe in it in the UK v 69% in Asia, p < 0.01); nutrition (92 v 58%, p < 0.01); and active recovery (70 v 52%, p = 0.03). The number of recovery techniques used with Asian athletes was higher after training (p = 0.009) and competition (p < 0.01). Asian athletes rely more on 'feel' to justify interventions. CONCLUSIONS: There was a major disconnect amongst athletes' belief in particular strategies and their behaviours. The results of this study show the need for educating coaches and athletes.

A Pilot Study Using Entropy as a Noninvasive Assessment of Running.

PURPOSE: Running performance is influenced by the interaction of biomechanical and physiological factors. Miniaturized accelerometers worn by athletes can be used to quantify mechanical aspects of running and as a noninvasive tool to assess training status and progression. The aim of this study was to define and validate a method to assess running regularity and allow the estimation of an individual's oxygen uptake (V̇O2) and/or blood lactate-[La]b-based on data collected with accelerometers and heart rate. METHODS: Male adolescent endurance athletes completed an incremental submaximal aerobic stage test where V̇O2 and [La]b were measured. The test was terminated when [La]b concentration at the end of the stage exceeded 4 mmol/L. Two wireless triaxial accelerometers were placed on participants' right shank and lower back throughout the test. The root mean square (RMS) and sample entropy (SampEn) were calculated for the vertical, mediolateral, and anteroposterior components of acceleration. RESULTS: There were significant positive correlations of acceleration and entropy variables with [La]b and V̇O2, with moderate to high coefficients (r = .43-.87). RMS of the shank acceleration was the most highly related with both physiological variables. When the accelerometer was attached on the trunk, SampEn of the vertical acceleration had the strongest relationship with V̇O2 (r = .76, P < .01). CONCLUSIONS: The described method analyzing running complexity may allow an assessment of gait variability, which noninvasively tracks V̇O2 and/or [La]b, allowing monitoring of fatigue or training readiness for trained adolescent individuals.

SIXTY SECONDS OF FOAM ROLLING DOES NOT AFFECT FUNCTIONAL FLEXIBILITY OR CHANGE MUSCLE TEMPERATURE IN ADOLESCENT ATHLETES.

BACKGROUND: Physiotherapists and other practitioners commonly prescribe foam rolling as an intervention, but the mechanistic effects of this intervention are not known. PURPOSE: The aim of this investigation was to establish if a single bout of foam rolling affects flexibility, skeletal muscle contractility and reflected temperature. METHODS: Twelve adolescent male squash players were evaluated on two separate occasions (treatment and control visits) and were tested on both legs for flexibility of the hip flexors and quadriceps, muscle contractility (as measured by tensiomyography) and temperature of the quadriceps (assessed via thermography) at repeated time points pre- and post a 60s rolling intervention (pre-, immediately post, 5, 10, 15, and 30 minutes post). They rolled one leg on the treatment visit and did not perform rolling on the control visit. RESULTS: The main outcome measure was the flexibility of hip flexor and quadriceps at repeated time points up to 30 minutes post intervention. The average foam rolling force was 68% of subject's body weight. This force affected the combination of hip and quadriceps flexibility (p = 0.03; 2.4 degrees total increase with foam rolling) but not each muscle independently (p = 0.05 - 0.98) following a single 60s bout. Muscle contractility is not affected (p = 0.09 - 0.93) and temperature is not increased by foam rolling across time points (p = 0.19). CONCLUSIONS: A single sixty-second bout of rolling applied to the quadriceps induces a small significant change in flexibility that is of little practical relevance, while muscle contractility and temperature remain unchanged. Investigation of larger doses of rolling is merited in athletic populations to justify current practice. LEVEL OF EVIDENCE: 2c.

The microstructure of coaching practice: behaviours and activities of an elite rugby union head coach during preparation and competition.

The activities and behaviours of a female head coach of a national rugby union team were recorded in both training and competition, across a whole rugby season, using the newly developed Rugby Coach Activities and Behaviours Instrument (RCABI). The instrument incorporates 24 categories of behaviour, embedded within three forms of activity (training form (TF), playing form (PF) and competitive match) and seven sub-activity types. In contrast to traditional drill-based coaching, 58.5% of the training time was found to have been spent in PF activities. Moreover, the proportion of PF activities increased to a peak average of 83.8% in proximity to the team's annual international championship. Uniquely, one of the coach's most prolific behaviours was conferring with associates (23.3%), highlighting the importance of interactions with assistant coaches, medical staff and others in shaping the coaching process. Additionally, the frequencies of key behaviours such as questioning and praise were found to vary between the different activity forms and types, raising questions about previous conceptions of effective coaching practice. The findings are discussed in the light of the Game Sense philosophy and the role of the head coach.

Re-examining the effects of verbal instructional type on early stage motor learning.

The present study investigated the differential effects of analogy and explicit instructions on early stage motor learning and movement in a modified high jump task. Participants were randomly assigned to one of three experimental conditions: analogy, explicit light (reduced informational load), or traditional explicit (large informational load). During the two-day learning phase, participants learned a novel high jump technique based on the 'scissors' style using the instructions for their respective conditions. For the single-day testing phase, participants completed both a retention test and task-relevant pressure test, the latter of which featured a rising high-jump-bar pressure manipulation. Although analogy learners demonstrated slightly more efficient technique and reported fewer technical rules on average, the differences between the conditions were not statistically significant. There were, however, significant differences in joint variability with respect to instructional type, as variability was lowest for the analogy condition during both the learning and testing phases, and as a function of block, as joint variability decreased for all conditions during the learning phase. Findings suggest that reducing the informational volume of explicit instructions may mitigate the deleterious effects on performance previously associated with explicit learning in the literature.

The PLUNGE randomized controlled trial: evaluation of a games-based physical activity professional learning program in primary school physical education.

OBJECTIVE: To evaluate the efficacy of the Professional Learning for Understanding Games Education (PLUNGE) program on fundamental movement skills (FMS), in-class physical activity and perceived sporting competence. METHODS: A cluster-randomized controlled trial involving one year six class each from seven primary schools (n=168; mean age=11.2 years, SD=1.0) in the Hunter Region, NSW, Australia. In September (2013) participants were randomized by school into the PLUNGE intervention (n=97 students) or the 7-week wait-list control (n=71) condition. PLUNGE involved the use of Game Centered curriculum delivered via an in-class teacher mentoring program. Students were assessed at baseline and 8-week follow-up for three object control FMS (Test of Gross Motor Development 2), in-class physical activity (pedometer steps/min) and perceived sporting competence (Self-perception Profile for Children). RESULTS: Linear mixed models revealed significant group-by-time intervention effects (all p<0.05) for object control competency (effect size: d=0.9), and in-class pedometer steps/min (d=1.0). No significant intervention effects (p>0.05) were observed for perceived sporting competence. CONCLUSIONS: The PLUNGE intervention simultaneously improved object control FMS proficiency and in-class PA in stage three students.