Does changing the Functional Movement Screen composite score threshold influence injury risk estimation in junior Australian football players?

This study aimed to identify whether a revised lower Functional Movement Screen (FMS) composite score threshold would be associated with a greater injury risk for junior athletes than the common threshold of≤14. This prospective cohort study included tracking of 809 elite junior male Australian football players for injuries that resulted in a missed game. All athletes completed pre-season FMS testing and a 12-month self-reported retrospective injury questionnaire. Analyses examined the relationship between composite score thresholds of≤14, ≤13, and≤12 and the risk of injury. The relationship between prospective injury and the common composite threshold score of ≤ 14 was dependent on the presence of a recent injury history (relative risk [RR] = 1.45, p = 0.004) in comparison to no recent injury history (RR = 0.98, p = 0.887). Scoring≤12 in the presence of a recent injury history had the greatest diagnostic accuracy but only a trivial increase in injury risk (RR = 1.59, p = 0.001, sensitivity = 0.35, specificity = 0.80, negative and positive likelihood ratios = 0.81 and 1.75). Whilst some small statistical relationships existed between prospective injury and the FMS composite score thresholds, all three thresholds were not associated with a clinically meaningful relationship with prospective injury and were no more effective than retrospective injury for determining athletes at risk of injury.

Validação da Escala de Autoeficácia no Voleibol para atletas de base (VSES-B) / Validación de la Escala de Autoeficacia de Voleibol para deportistas jóvenes (VSES-B) / Validation of the Volleyball Self-Efficacy Scale for youth athletes (VSES-B)

The aim of this study was to psychometrically test the Volleyball Self-Efficacy Scale for Brazilian athletes from youth categories. The study was conducted in four stages, with four different sample groups. For content-based evidence analysis, a group of 20 athletes participated, with a mean age of 14.30 ± 1.17 years and practice time of 4.60 ± 2.10 years, for semantic analysis, after a group of four students, with a mean age of 35.75 ± 12.23 years and experience time 25.0 ± 11.02 years, to verify the semantic analysis and another group of 20 athletes, with a mean age of 14.45 ± 1.30 years and practice time 5.50 ± 2.20 years for the pilot study. To test the evidence based on the internal structure and the evidence based on other variables, a group of 454 base athletes, of both sexes, with a mean age of 14.33 ± 1.18 years and practice time 3.79 ± 2.13 years was verified. The results pointed to evidence based on content, evidence based on internal structure and evidence based on other variables, through convergent validity (collective efficacy and results of Confirmatory Factor Analysis) and discriminant (Average Variance Extracted and correlation between the dimensions of the VSES-B). The validation process of the Volleyball Self-Efficacy Scale for Base Athletes allows us to conclude that the instrument has good psychometric properties to measure self-efficacy, considering technical, tactical, conditioning and psychological skills of emotional cognitive self-control that are part of the sport context of the modality. In addition, it provides relevant information for the development of future psychometric research based on contemporary validity references.

El objetivo de este estudio fue probar psicométricamente la Escala de Autoeficacia del Voleibol para deportistas brasileños de categorías juveniles. El estudio se llevó a cabo en cuatro etapas, con cuatro grupos de muestra diferentes. Para el análisis de evidencia basada en contenido, participó un grupo de 20 deportistas, con una edad media de 14.30 ± 1.17 años y tiempo de práctica de 4.60 ± 2.10 años, para el análisis semántico, después de un grupo de cuatro académicos, con una edad media de 35.75 ± 12.23 años y tiempo de experiencia 25.0 ± 11.02 años, para verificar el análisis semántico y otro grupo de 20 deportistas, con una edad media de 14.45 ± 1.30 años y tiempo de práctica 5.50 ± 2.20 años para el estudio piloto. Para probar la evidencia basada en la estructura interna y la evidencia basada en otras variables, se verificó un grupo de 454 atletas de base, de ambos sexos, con una edad media de 14.33 ± 1.18 años y tiempo de práctica 3.79 ± 2.13 años. Los resultados apuntaron a evidencia basada en contenido, evidencia basada en estructura interna y evidencia basada en otras variables, mediante validez convergente (eficacia colectiva y resultados del Análisis Factorial Confirmatorio) y discriminante (Varianza Media Extraída y correlación entre las dimensiones del VSES-B). El proceso de validación de la Escala de Autoeficacia de Voleibol para Atletas de Base nos permite concluir que el instrumento tiene buenas propiedades psicométricas para medir la autoeficacia, considerando las habilidades técnicas, tácticas, condicionantes y psicológicas de autocontrol cognitivo emocional que forman parte del contexto deportivo de la modalidad. Además, proporciona información relevante para el desarrollo de futuras investigaciones psicométricas basadas en referencias de validez contemporáneas.

O objetivo deste estudo foi testar psicometricamente a Escala de Autoeficácia no Voleibol para atletas brasileiros de categorias de base. O estudo foi conduzido em quatro etapas, com quatro diferentes grupos amostrais. Para análise das evidências baseadas no conteúdo, participaram um grupo de 20 atletas, com média de idade 14.30 ± 1.17 anos e tempo de prática 4.60 ± 2.10 anos, para análise semântica, logo após um grupo de quatro acadêmicos, com média de idade 35.75 ± 12.23 anos e tempo de experiência 25.0 ± 11.02 anos, para verificação da análise semântica e outro grupo de 20 atletas, com média de idade 14.45 ± 1.30 anos e tempo de prática 5.50 ± 2.20 anos para o estudo piloto. Para testar as evidências baseadas na estrutura interna e as evidências baseadas em outras variáveis, um grupo de 454 atletas de base, de ambos os sexos, com média de idade 14.33 ± 1.18 anos e tempo de prática 3.79 ± 2.13 anos foi verificado. Os resultados apontaram para evidências baseadas no conteúdo, evidências baseadas na estrutura interna e evidências baseadas em outras variáveis, por meio da validade convergente (eficácia coletiva e resultados da Análise Fatorial Confirmatória) e discriminante (Variância Média Extraída e correlação entre as dimensões da VSES-B). O processo de validação da Escala de Autoeficácia no Voleibol para Atletas de Base permite concluir que o instrumento possui boas propriedades psicométricas para mensurar a autoeficácia, considerando aspectos técnicos, táticos, condicionantes e habilidades psicológicas de autocontrole cognitivo emocional que fazem parte do contexto esportivo da modalidade. Além disso, fornece informações relevantes para o desenvolvimento de pesquisas psicométricas futuras baseadas em referências contemporâneas de validade.

Individual Fluctuations in Blood Lactate Concentration During an Ice Hockey Game; Differences Between Player Positions.

The main purpose of the current study was to provide an in-depth description of individual player's intra-game physiological responses during an ice hockey game. A secondary aim was to compare these responses between forwards and defensemen. Six elite junior ice hockey players, three forwards and three defensemen, median (interquartile range) 17 (17-17) years, 182 (180-185) cm, and 78 (74-80) kg were recruited to participate in the study. Capillary blood samples were taken following each shift and analyzed for blood lactate concentration (BLC). Heart rate (HR) was registered continuously throughout the game. The game was filmed and shift lengths were determined retrospectively using a time-motion analysis. All players had BLC ranging between 1.8 and 10.7 mmol/L (mean = 5.5 mmol/L), with forwards reaching a significantly higher value than defensive players (F 1, 32 = 75.2, p < 0.0001), a significant effect of time was also observed (F 2, 25 = 6.4, p = 0.0058). During the game, the players accumulated 11:18 ± 5:04 (minutes:seconds) above 90% of their maximal heart rate (HRmax), but the majority of the time was below 80% of HRmax. The fluctuations in BLC and heart rate demonstrate that the intensity is highly variable during games and challenges both aerobic and anaerobic metabolic pathways. The higher BLC of forwards might indicate that they perform more high-intensity work during games than defensive players.

Attitudes and Opinions of Parents towards Water-Only Drink Policy at Junior Triathlon Events.

Rates of childhood obesity within Australia continue to rise, with consumption of sugar-sweetened beverages one contributing factor. Community sport provides an opportunity to implement policies promoting water as the beverage of choice. However, the attitudes of parents toward a water-only policy are not known. This cross-sectional study aimed to investigate parents' opinions towards beverage consumption and a water-only policy. Data were collected from participants (n = 159) using an investigator-designed questionnaire, administered using iPads, at a junior Triathlon Victoria event. Water was the most popular beverage provided before (75%), during (85%) and after (61%) sport. Parents were more likely to provide sports drinks to children older than 14 years (27%). Three-quarters (77%) of parents reported having received no information regarding hydration requirements. Parents rated the importance of hydration prior to, during and after a triathlon as high (9.08 ± 1.2, 8.76 ± 1.3 and 9.30 ± 0.4 out of 10, respectively). Parents were supportive of a water-only policy at all junior triathlon events and all junior sporting events (7.94 ± 1.3 and 7.86 ± 1.9, respectively). There was less support for a water-only policy for adult triathlons (6.40 ± 3.1). A water-only drink policy at junior sport is viewed positively by parents. This warrants further research and policy development to facilitate behaviour change.

Development of perfectionism in junior athletes: Examination of actual and perceived parental perfectionism.

Initial research suggests that parental perfectionism is central to the development of athlete perfectionism. However, it is unclear whether perceived or actual parental perfectionism is most important. The present study aimed to address this issue in two ways. First, we re-examined the predictive ability of actual versus perceived parental perfectionism on athlete perfectionism. Second, for the first time, we tested whether perceived parental perfectionism mediated the relationship between actual parental perfectionism and athlete perfectionism. A sample of 150 junior athletes and their parents completed measures of perfectionism (perfectionistic strivings and perfectionistic concerns). Junior athletes completed two measures, one of their own perfectionism and one of perceptions of their parents' perfectionism. Parents completed one measure of their own perfectionism. Regression analyses showed that perceived parental perfectionism predicted athlete perfectionism over and above actual parental perfectionism. Mediation analyses provided support for our proposed model. Overall, the findings suggest that both actual and perceived parental perfectionism are important in the development of perfectionism in junior athletes.

Influence of Vigorous Physical Activity on Structure and Function of the Cardiovascular System in Young Athletes-The MuCAYA-Study.

Objective: Moderate physical activity (PA) is associated with a reduced risk to develop cardiovascular disease. However, junior athletes exercise between 10 and 20 h a week with intensities exceeding moderate levels by far. In this regard, the cardiovascular system has to increase its work five to six times compared to moderate intensities. This may result in potentially pathological adaptations of the cardiovascular system. The underlying process of vascular adaptations to exercise is yet not fully understood and hardly investigated in junior athletes. An increased blood pressure and pulse wave velocity, ventricular hypertrophy, arrhythmia, and even sudden cardiac death (SCD) has been reported in adult athletes. Studies, examining the cardiovascular system in children, its association to intensity and type of exercise, are rare. Therefore, we present the study protocol of a prospective cross-sectional study that investigates the influence of PA on the cardiovascular system in young athletes. Methods and Design: Children and adolescents, 7-18 years, presenting for their annual pre-participation screening at the Institute of Preventive Pediatrics, Faculty of Sports and Health Sciences, Technical University of Munich (TUM), are examined in this prospective cross-sectional study. Vascular parameters measured by ultrasound are carotid intima-media thickness (cIMT), vascular stiffness (AC, Ep, ß, PWV ß), and the vascular diameter (D) to calculate the IMT:Diameter-Ratio (IDR). Cardiac function is evaluated by a 12-lead ECG, and echocardiographic parameters (end-diastolic left ventricular diameter, left ventricular diastolic posterior wall thickness, diastolic septal thickness, left ventricular mass and relative wall thickness, ejection fraction, and shortening fraction). A cardiopulmonary exercise test is performed on a bicycle ergometer, muscular strength is assessed with the handgrip test, and physical activity with the MoMo questionnaire. Discussion: It is essential to follow young athletes over the course of their career in order to detect pathophysiological changes in the myocardium as soon as possible. If these changes are preceded or followed by changes in vascular structure and function is not known yet. Therefore, we present the study protocol of the Munich Cardiovascular adaptations in young athletes study (MuCAYA-Study) which investigates the association between vascular and cardiac adaptation to intensive exercise in junior athletes.

Perfectionism and Precompetition Emotions in Youth Footballers: A Three-Wave Longitudinal Test of the Mediating Role of Perfectionistic Cognitions.

Perfectionism is related to precompetition emotions in athletes. However, it is unclear why this is the case. In the present study, the authors sought to determine whether perfectionistic cognitions explain this relationship and mediate the relationships between self-oriented perfectionism (SOP), socially prescribed perfectionism (SPP), and general precompetition emotions and multidimensional anxiety and anger. The authors adopted a three-wave longitudinal design and examined between- and within-person effects in a sample of 352 youth footballers (Mage = 14.03 years, SD = 2.30). At the between-person level, perfectionistic cognitions mediated the relationships between SOP, SPP, and all general precompetition emotions plus multidimensional anxiety and anger. At the within-person level, perfectionistic cognitions mediated the relationships between SOP, SPP, and general anxiety and anger plus multidimensional anxiety and anger. Our findings imply that athletes higher in SOP and SPP experience more anxiety and anger when the frequency of perfectionistic cognitions increases in the lead-up to competition.

[Immunomodulating effects of using L-carnitine and coenzyme Q10 in the nutrition of junior athletes].

Nowdays, much attention is paid to the study of disorders of immune regulation and methods of effective immune correction in athletes. In this regard, the use of specialized sport foods (SSF), containing nutrients with immunomodulatory properties, is of particular relevance in youth sports. The aim of the work is to study the immunomodulating activity of L-carnitine and coenzyme Q10 in junior athletes during the training period. Material and methods. The object of the study were 30 junior athletes (masters of sports and candidates for masters of sports in swimming) aged 14-18 years, including 9 girls and 21 boys. Athletes were divided into 3 groups of 10 people each. Athletes of the 1st and 2nd main groups received L-carnitine (600 mg per day) and coenzyme Q10 (60 mg/day), respectively, for 4 weeks in addition to the basic diet. The dosage of SSF used in the study was 200% of the adequate level of consumption and did not exceed the upper permissible level of consumption. Athletes of the 3rd group (control) received only basic diet without sports' nutrition. Examination of athletes of all groups was performed at the beginning and after 4 weeks of the observation period. Results and discussion. As a result of a comprehensive survey of junior athletes, the positive effect of L-carnitine intake on erythrocyte hemoglobin content (30.2±0.4 vs 28.3±0.3 pg at the beginning) was observed. The relative content of basophilic leukocytes in athletes of the main groups statistically significantly decreased by the end of the observation period: in the L-carnitine group, from 0.64±0.05 to 0.45±0.04%, in the coenzyme Q10 group, from 0.66±0.07 to 0.50±0.04%, which indicated an increase in the body's resistance to allergic reactions. Conclusion. The biomarkers of the immunotropic effect of L-carnitine and coenzyme Q10 are a decrease in the expression of the apoptotic marker CD95/Fas on peripheral blood lymphocytes and suppression of the production of pro-inflammatory cytokines synthesized by Th1-lymphocytes with switching the response to humoral immunity. An evidence base for the effectiveness of the use of L-carnitine and coenzyme Q10 in sports nutrition for restoring immune dysfunction and adaptive potential of junior athletes has been provided.

Perfectionism and training distress in junior athletes: The mediating role of coping tendencies.

Training distress occurs when athletes fail to cope with physiological and psychological stress and can be an early sign of overtraining syndrome. Recent research has found that perfectionism predicts increases in training distress in junior athletes over time. The current study provides the first empirical test of the possibility that coping tendencies mediate the perfectionism-training distress relationship. Adopting a cross-sectional design, 171 junior athletes (mean age = 18.1 years) completed self-report measures of perfectionistic strivings, perfectionistic concerns, problem-focused coping, avoidant coping, and training distress. Structural equation modelling revealed that avoidant coping mediated the positive relationship between perfectionistic concerns and training distress, and mediated the negative relationship between perfectionistic strivings and training distress. Problem-focused coping did not mediate any relationships between dimensions of perfectionism and training distress. The findings suggest that the tendency to use coping strategies aimed at avoiding stress may partly explain the relationship between perfectionism and training distress but the tendency to use, or not use, problem-focussed coping does not.

Perfectionism predicts injury in junior athletes: Preliminary evidence from a prospective study.

According to the stress-injury model (Williams & Andersen, 1998), personality factors predisposing athletes to elevated levels of stress may increase the risk of injury. As perfectionism has been associated with chronic stress, it may be one such personality factor. So far, however, no study has investigated the relationships between perfectionism and injury utilising a prospective design. Therefore, the present study examined perfectionistic strivings, perfectionistic concerns and injury in 80 junior athletes from team and individual sports (mean age 17.1 years; range 16-19 years) over 10 months of active training. The results of logistic regression analyses showed that perfectionism positively predicted injury, but only perfectionistic concerns emerged as a significant positive predictor. The likelihood of sustaining an injury was increased by over two times for each 1 SD increase in perfectionistic concerns. The findings suggest that perfectionistic concerns may be a possible factor predisposing athletes to an increased risk of injury.

The Importance Of Visual Awareness Among Junior Athletes In Klang Valley, Malaysia

The lack of awareness about comprehensive eye examination amongst athletes could impact their eye health, hence it needs to be addressed. The authors hypothesize that a majority of athletes in Malaysia have never undergone a thorough eye examination. The present study aims to determine Malaysian athletes’ awareness of the importance of eye assessment. One hundred and twenty-one junior athletes, aged 13 to 16 years participated in the visual screening programme. A questionnaire consisting of fourteen dichotomous questions was developed in two languages, each being English and Malay language and administered prior to eye examination. The questionnaire was designed to measure self-reported visual function, ocular symptoms, and perceptions towards eye health. Questionnaire analysis showed 67.8% of participants never underwent any eye examination. A majority of participants, 66.9% and 75.2%, complained of visual and ocular symptoms respectively. The critical finding of this study showed that 57.9% of participants had reduced vision which could be visually corrected. Overall 90.9% of the participants agreed that eye examination was important. Almost none of the athletes owned any sports safety eyewear nor had undergone any visual training. The importance of wearing protective eyewear during sports needs to be given emphasis. This study implies that athletes' awareness of eye health, as well as visually related issues, is still at a very low level. Hence, the need for comprehensive eye examination and regular review among athletes’ needs to be emphasized. Athletes should also be educated on the importance of regular eye examinations from a young age.

Gunslingers, poker players, and chickens 3: Decision making under mental performance pressure in junior elite athletes.

BACKGROUND: Having investigated the decision making of world class elite and subelite athletes (see Parkin and Walsh, 2017; Parkin et al., 2017), here the abilities of those at the earliest stage of entry to elite sport are examined. Junior elite athletes have undergone initial national selection and are younger than athletes examined previously (mean age 13 years). Decision making under mental pressure is explored in this sample. During performance an athlete encounters a wide array of mental pressures; these include the psychological impact of errors, negative feedback, and requirements for sustained attention in a dynamic environment (Anshel and Wells, 2000; Mellalieu et al., 2009). Such factors increase the cognitive demands of the athletes, inducing distracting anxiety-related thoughts known as rumination (Beilock and Gray, 2007). Mental pressure has been shown to reduce performance of decision-making tasks where reward and loss contingencies are explicit, with a shift toward increased risk taking (Pabst et al., 2013; Starcke et al., 2011). Mental pressure has been shown to be detrimental to decision-making speed in comparison to physical stress, highlighting the importance of considering a range of different pressures encountered by athletes (Hepler, 2015). OBJECTIVE: To investigate the influence of mental pressure on key indicators of decision making in junior elite athletes. This chapter concludes a wider project examining decision making across developmental stages in elite sport. The work further explores how psychological insights can be applied in an elite sporting environment and in particular tailored to the requirements of junior athletes. METHODS: Seventeen junior elite athletes (10 males, mean age: 13.80 years) enrolled on a national youth athletic development program participated in the study. Performance across three categories of decision making was assessed under conditions of low and high mental pressure. Decision making under risk was measured via the Cambridge Gambling Task (CGT; Rogers et al., 1999), decision making under uncertainty via the Balloon Analogue Risk Task (BART; Lejuez et al., 2002), and fast reactive responses to perceptual stimuli via the Visual Search Task (Treisman, 1982). Mental pressure was induced with the addition of a concurrent verbal memory task, used to increase cognitive load and mimic the distracting effects of anxiety-related rumination. RESULTS: In junior elite athletes, fast reactive responses to perceptual stimuli (on the Visual Search Task) were slower under conditions of mental pressure. For decision making under risk there was an interaction of mental pressure and gender on the amount of points gambled, under pressure there was a higher level of risk taking in male athletes compared to females. There was no influence of mental pressure on decision making under uncertainity. There were no significant correlations in the degree to which individual's responses changed under pressure across the three measures of decision making. When assessing the applicability of results based on group averages there were no junior elite athletes who showed an "average" response (within 1SD of the mean) to mental pressure across all the three decision-making tasks. CONCLUSION: Mental pressure affects decision making in a sample of junior elite athletes, with a slowing of response times, and modulations to performance of decision making under risk that have a high requirement for working memory. In relation to sport, these findings suggest that novel situations that place high cognitive demands on the athlete may be particularly influenced by mental pressure. The application of this work in junior elite athletes included the feedback of individual results and the implementation of a decision-making taxonomy.

Tensiomyographic Markers Are Not Sensitive for Monitoring Muscle Fatigue in Elite Youth Athletes: A Pilot Study.

Objective: Tensiomyography (TMG) is an indirect measure of a muscle's contractile properties and has the potential as a technique for detecting exercise-induced skeletal muscle fatigue. Therefore, the aim of this study was to assess the sensitivity of tensiomyographic markers to identify reduced muscular performance in elite youth athletes. Methods: Fourteen male junior tennis players (age: 14.9 ± 1.2 years) with an international (International Tennis Federation) ranking position participated in this pre-post single group trial. They completed a 4-day high-intensity interval training (HIT) microcycle, which was composed of seven training sessions. TMG markers; countermovement jump (CMJ) performance (criterion measure of fatigue); delayed onset muscle soreness; and perceived recovery and stress were measured 24 h before and after the training program. The TMG measures included maximal radial deformation of the rectus femoris muscle belly (Dm), contraction time between 10 and 90% Dm (Tc) and the rate of deformation until 10% (V10) and 90% Dm (V90), respectively. Diagnostic characteristics were assessed with a receiver-operating curve (ROC) analysis and a contingency table, in which the area under the curve (AUC), Youden's index, sensitivity, specificity, and the diagnostic effectiveness (DE) of TMG measures were reported. A minimum AUC of 0.70 and a lower confidence interval (CI) >0.50 classified "good" diagnostic markers to assess performance changes. Results: Twenty-four hours after the microcycle, CMJ performance was observed to be significantly (p < 0.001) reduced (Effect Size [ES] = -0.68), and DOMS (ES = 3.62) as well as perceived stress were significantly (p < 0.001) increased. In contrast, Dm (ES = -0.35), Tc (ES = 0.04), V10 (ES = -0.32), and V90 (ES = -0.33) remained unchanged (p > 0.05) throughout the study. ROC analysis and the data derived from the contingency table revealed that none of the tensiomyographic markers were effective diagnostic tools for detecting impaired muscular performance in elite youth athletes (AUC, 95% CI, DE%; Dm: 0.46, 0.15-0.77, 35.7%; Tc: 0.29, 0.03-0.59, 35.7%; V10: 0.71, 0.27-1.00, 35.7%; V90: 0.37, 0.10-0.65, 35.7%). Conclusion: The tensiomyographic parameters that were assessed in this study were not sensitive enough to detect muscular performance changes in elite youth athletes.However, due to the preliminary nature of the study, further research is needed to investigate the sensitivity of TMG in this population.

No Additional Benefits of Block- Over Evenly-Distributed High-Intensity Interval Training within a Polarized Microcycle.

Introduction: The current study aimed to investigate the responses to block- versus evenly-distributed high-intensity interval training (HIT) within a polarized microcycle. Methods: Twenty well-trained junior cross-country skiers (10 males, age 17.6 ± 1.5 and 10 females, age 17.3 ± 1.5) completed two, 3-week periods of training (EVEN and BLOCK) in a randomized, crossover-design study. In EVEN, 3 HIT sessions (5 × 4-min of diagonal-stride roller-skiing) were completed at a maximal sustainable intensity each week while low-intensity training (LIT) was distributed evenly around the HIT. In BLOCK, the same 9 HIT sessions were completed in the second week while only LIT was completed in the first and third weeks. Heart rate (HR), session ratings of perceived exertion (sRPE), and perceived recovery (pREC) were recorded for all HIT and LIT sessions, while distance covered was recorded for each HIT interval. The recovery-stress questionnaire for athletes (RESTQ-Sport) was completed weekly. Before and after EVEN and BLOCK, resting saliva and muscle samples were collected and an incremental test and 600-m time-trial (TT) were completed. Results: Pre- to post-testing revealed no significant differences between EVEN and BLOCK for changes in resting salivary cortisol, testosterone, or IgA, or for changes in muscle capillary density, fiber area, fiber composition, enzyme activity (CS, HAD, and PFK) or the protein content of VEGF or PGC-1α. Neither were any differences observed in the changes in skiing economy, [Formula: see text] or 600-m time-trial performance between interventions. These findings were coupled with no significant differences between EVEN and BLOCK for distance covered during HIT, summated HR zone scores, total sRPE training load, overall pREC or overall recovery-stress state. However, 600-m TT performance improved from pre- to post-training, irrespective of intervention (P = 0.003), and a number of hormonal and muscle biopsy markers were also significantly altered post-training (P < 0.05). Discussion: The current study shows that well-trained junior cross-country skiers are able to complete 9 HIT sessions within 1 week without compromising total work done and without experiencing greater stress or reduced recovery over a 3-week polarized microcycle. However, the findings do not support block-distributed HIT as a superior method to a more even distribution of HIT in terms of enhancing physiological or performance adaptions.

Perfectionism and training distress in junior athletes: a longitudinal investigation.

Perfectionistic athletes may train harder and for longer than non-perfectionistic athletes, leaving them susceptible to elevated levels of training distress. So far, however, no study has investigated the relationships between perfectionism and training distress, a key indicator of overtraining syndrome. Furthermore, no study has determined psychological predictors of overtraining syndrome. Using a two-wave design, the present study examined perfectionistic strivings, perfectionistic concerns and training distress in 141 junior athletes (mean age = 17.3 years, range = 16-19 years) over 3 months of active training. Multiple regression analyses were employed to test cross-sectional and longitudinal relationships between perfectionism and training distress. In all analyses, perfectionism emerged as a significant predictor, but strivings and concerns showed differential relationships. When the cross-sectional relationships were regarded, perfectionistic concerns positively predicted training distress (P < .001), whereas perfectionistic strivings negatively predicted training distress (P < .01). When the longitudinal relationships were regarded, only perfectionistic concerns predicted increases in training distress (P < .05), whereas perfectionistic strivings did not (P > .05). The findings suggest that sports scientists who wish to identify athletes at risk of overtraining syndrome may monitor athletes' perfectionistic concerns as a possible risk factor.

Exhaustion Experiences in Junior Athletes: The Importance of Motivation and Self-Control Competencies.

Quality of motivation, self-control competencies, as well as past performance experience influence sport participation outcomes in developing athletes. Studies have shown that junior athletes high in self-determined motivation are less prone to experience burnout, while self-control competencies help developing athletes to be conscious and deliberate in their self-regulatory efforts toward elite sport performances and avoid negative sport participation outcomes. Combining the self-determination theory framework and psychosocial theories of self-regulation, the aim of this cross-sectional study was to examine how various types of motivation and self-control competencies together are associated with the development of burnout symptoms in junior athletes. High-level Norwegian winter-sport athletes from elite sport academies (N = 199; female n = 72; 16-20 years of age) consented to participate. Associations between six types of motivational regulation, self-control, and indices of exhaustion were investigated. We hypothesized that athletes' self-control competencies are important to operate successfully, and influenced by different types of motivation, they are expected to help athletes avoid negative sport participation outcomes such as emotional and physical exhaustion. Structural equation modeling analyses were conducted to analyze these relationships, and results revealed some multifaceted associations. When identifying antecedents of sport participation exhaustion and burnout, there is a need to go beyond the unique framework of motivation theories, and explore what cognitive competencies ensure fulfillment of motivation desires. In the current study, differences in junior athletes' quality of motivation influenced self-control competencies when predicting exhaustion. Interestingly, young athletes driven by self-determined (intrinsic, integrated, and identified), and controlled (introjected and amotivation) regulations in association with self-control offered the strongest negative and positive associations with exhaustion, respectively. Findings clearly indicate that motivation and self-control competencies are meaningfully interrelated when assessing burnout propensity in young developing athletes.

Structural and biomechanical changes in shoulders of junior javelin throwers: a comprehensive evaluation as a proof of concept for a preventive exercise protocol.

PURPOSE: The purpose of this study was to develop a preventive exercise protocol based on structural and functional changes present in shoulder joints of young throwing athletes. As a proof of concept, these changes were previously evaluated in a cross-section of high-performance junior javelin throwers. METHODS: Thirteen members of the German and Bavarian junior javelin squad (mean age 17.5 ± 0.8 years) completed a systematic clinical examination, shoulder range of motion (ROM) measurement, and were scored with standardized clinical tools. 3.0 tesla magnetic resonance imaging (MRI) was conducted on both shoulders. Bilateral three-dimensional analysis of the scapulothoracic motion during multiplanar humeral elevation and isokinetic strength testing of the shoulder internal and external rotators was accomplished. Based on the findings, a preventive exercise protocol was confirmed. RESULTS: Dominant internal ROM was significantly decreased (dominant 48° ± 20° vs. non-dominant 57° ± 19°; P = 0.006) and dominant external ROM increased (dominant 117° ± 15° vs. non-dominant 107° ± 10°; P = 0.008). MRI revealed posterosuperior intraosseous cysts of the humeral head with a size larger than >3 mm in 69 % of the dominant shoulders and only in 15 % in the non-dominant shoulders. Motion analysis of the static scapular resting position was significantly different between dominant and non-dominant sides regarding anterior tilt (dominant > non-dominant, mean difference 4.2°, P = 0.010) and retraction (dominant > non-dominant, mean difference 2.4°, P = 0.038). Dominant scapular anterior tilt during flexion and abduction was significantly increased (-4.3°, P = 0.006; -3.4°, P = 0.046). Dominant retraction was significantly increased during abduction (-2.3°, P = 0.040). Isokinetic outcome parameters presented nonsignificant bilateral differences. CONCLUSIONS: Elite junior javelin throwers already present structural (humeral intraosseous cysts) and biomechanical changes (ROM deficits and asymmetric scapulothoracic motion patterns), even if they have no history of major shoulder pain or injury. A novel exercise protocol was developed in order to address the complex of alterations in a comprehensive way. Preventive diagnostics in combination with a systematic all-year preventive exercise intervention might be one option to detect and control risk factors of a symptomatic throwing shoulder at an early stage. LEVEL OF EVIDENCE: IV.

Upper body heavy strength training does not affect performance in junior female cross-country skiers.

We investigated the effects of adding heavy strength training to a high volume of endurance training on performance and related physiological determinants in junior female cross-country skiers. Sixteen well-trained athletes (17 ± 1 years, 60 ± 6 kg, 169 ± 6 cm, VO2max running: 60 ± 5 mL/kg/min) were assigned either to an intervention group (INT; n = 9) or a control group (CON; n = 7). INT completed two weekly sessions of upper body heavy strength training in a linear periodized fashion for 10 weeks. Both groups continued their normal aerobic endurance and muscular endurance training. One repetition maximum in seated pull-down increased significantly more in INT than in CON, with a group difference of 15 ± 8% (P < 0.01). Performance, expressed as average power output on a double poling ergometer over 20 s and as 3 min with maximal effort in both rested (sprint-test) and fatigued states (finishing-test), showed similar changes in both groups. Submaximal O2 -cost and VO2peak in double poling showed similar changes or were unchanged in both groups. In conclusion, 10 weeks of heavy strength training increased upper body strength but had trivial effects on performance in a double poling ergometer in junior female cross-country skiers.

Perfectionism and attitudes towards doping in junior athletes.

Recent theory and research suggest that perfectionism is a personal factor contributing to athletes' vulnerability to doping (using banned substances/drugs to enhance sporting performance). So far, however, no study has examined what aspects of perfectionism suggest a vulnerability in junior athletes. Employing a cross-sectional design, this study examined perfectionism and attitudes towards doping in 129 male junior athletes (mean age 17.3 years) differentiating four aspects of perfectionism: perfectionistic strivings, perfectionistic concerns, parental pressure to be perfect, and coach pressure to be perfect. In the bivariate correlations, only parental pressure showed a positive relationship with positive doping attitudes. In a multiple regression analysis controlling for the overlap between the four aspects, perfectionistic strivings additionally showed a negative relationship. Moreover, a structural equation model examining the relationships between all variables suggested that coach pressure had a negative indirect effect on attitudes towards doping via perfectionistic strivings. The findings indicate that perceived parental pressure to be perfect may be a factor contributing to junior athletes' vulnerability to doping, whereas perfectionistic strivings may be a protective factor.