Leadership in Finnish elite football: associations between players' self-assessed leadership roles and player-assessed head coach leadership behavior by player gender and age.

We investigated the associations between Finnish top tier footballers' self-assessed leadership roles (task, motivational, social, external) and player-assessed head coach leadership behavior (supportiveness/emotional composure, negative activation) and leadership role in both practices and games. We also explored the player age- and gender-related differences. Online survey data were anonymously collected from 53 male and 91 female footballers. One player did not identify as male or female, and one chose not to answer the question. Spearman rank-order correlations revealed that players' self-assessed leadership roles correlated positively with their evaluation of their head coach's supportiveness/emotional composure and negatively with negative activation during practices and games. Independent samples T-tests showed that male footballers rated their head coaches lower on negative activation during games and practices and themselves higher on external leadership than female players. The youngest age group, aged 17-20, rated themselves also lower on external leadership than the three older groups.

Adherence to an Injury Prevention Warm-Up Program in Children's Soccer-A Secondary Analysis of a Randomized Controlled Trial.

This study examined the impact of high adherence to a neuromuscular training (NMT) warm-up on the risk of lower extremity (LE) injuries in children's soccer. Twenty U11-U14 youth clubs (n = 92 teams, 1409 players) were randomized into intervention (n = 44 teams) and control (n = 48 teams) groups. The intervention group was advised to perform an NMT warm-up 2 to 3 times a week for 20 weeks. Team adherence, injuries, and exposure were registered throughout the follow-up. Primary outcomes were the incidence of soccer-related acute LE injuries and the prevalence of overuse LE injuries. Intervention teams conducted mean 1.7 (SD 1.0) NMT warm-ups weekly through follow-up. The seasonal trend for adherence declined significantly by -1.9% (95% CI -0.8% to -3.1%) a week. There was no difference in the incidence of acute injuries nor the prevalence of overuse LE injuries in high team adherence group (n = 17 teams) compared to controls. However, the risk for acute noncontact LE injuries was 31% lower in the high team adherence group compared to controls (IRR 0.69, 95% CI 0.49 to 0.97). In an efficacy analysis (n = 7 teams), there was a significant reduction of 47% in the rate of noncontact LE injuries (IRR 0.53, 95% CI 0.29 to 0.97). In conclusion, teams conducted NMT warm-up sessions regularly, but with a declining trend. A greater protective effect was seen in teams with the highest adherence to the NMT warm-up.

Neuromuscular Training Warm-up Prevents Acute Noncontact Lower Extremity Injuries in Children's Soccer: A Cluster Randomized Controlled Trial.

BACKGROUND: Prevention of sports injuries is essential in youth, as injuries are associated with less future physical activity and thus greater all-cause morbidity. PURPOSE: To investigate whether a neuromuscular training warm-up operated by team coaches is effective in preventing acute lower extremity (LE) injuries in competitive U11-U14 soccer players. STUDY DESIGN: Randomized controlled trial; Level of evidence, 1. METHODS: Twenty top-level U11 to U14 soccer clubs in Finland were randomized into intervention and control groups and assessed for 20 weeks. Participants included 1403 players (280 female, 1123 male; age range, 9-14 years): 673 players (44 teams) in the intervention group and 730 players (48 teams) in the control group. The intervention group team coaches were introduced to a neuromuscular training warm-up to replace the standard warm-up 2 to 3 times per week. The control teams were asked to perform their standard warm-up. Injury data collection was done via weekly text messages. The primary outcome measure was a soccer-related acute LE injury, and the secondary outcome measure was an acute noncontact LE injury. RESULTS: A total of 656 acute LE injuries occurred: 310 in the intervention group and 346 in the control group. The overall acute LE injury incidence was 4.4 per 1000 hours of exposure in the intervention group and 5.5 per 1000 hours of exposure in the control group, with no significant difference between groups (incidence rate ratio [IRR], 0.82 [95% CI, 0.64-1.04]). There were 302 acute noncontact LE injuries: 129 in the intervention group (incidence, 1.8 per 1000 hours) and 173 in the control group (2.7 per 1000 hours). A significant reduction in acute noncontact LE injuries of 32% (IRR, 0.68 [95% CI, 0.51-0.93]) was observed in the intervention group compared with the control group. Furthermore, significant reductions in injury incidence in favor of the intervention group were seen in the subanalyses of acute noncontact LE injuries, leading to ≤7 days of time loss and fewer ankle and joint/ligament injuries. CONCLUSION: A neuromuscular training warm-up operated by team coaches was found to be effective in preventing acute noncontact LE injuries in children's soccer, but this was not seen in all acute LE injuries. CLINICAL RELEVANCE: We encourage children's soccer coaches and health care professionals to implement neuromuscular training warm-up in youth sports. REGISTRATION: ISRCTN14046021 (ISRCTN registry).

Objectively assessed vigorous physical activity and motor coordination are associated in 11-year old children.

This cross-sectional study examined the associations between gender, sports club (SC) participation, physical activity (PA), motor coordination (MQ) and object control skill (TC). 11 year-old children (n = 477) wore accelerometers during seven consecutive days for the analysis of moderate PA (MPA) and vigorous PA (VPA). To detect motor competence (MC), children's motor coordination was measured using the KTK (MQ), and object control skill with throw-and-catch task (TC). Sports club (SC) status was obtained by a questionnaire. Boys had higher levels of MPA (F = 50.45, P<0.001) and VPA (F = 11.13, P = 0.001), and were better in TC (F = 39.83, P < 0.001) than girls. SC participants outperformed non-participants in MPA (F = 5.45, P = 0.020) and VPA (F = 11.71, P = 0.001), MQ (F = 31.56, P < 0.001), and TC (F = 15.60, P < 0.001). Moreover, better TC was associated with higher MPA (ß = 0.88, t = 2.16, P = 0.031), and higher MQ was associated with higher VPA (ß = 0.21, t = 3.87, P < 0.001). The association between PA and MC was found showing that different intensities of PA were associated with different aspects of MC. SC participation may be one important factor promoting PA and MC in children. Therefore, all children, especially girls, should be encouraged to participate in various practices to ensure the development of adequate level of motor competence to be physically active.

Individual Motivations, Motivational Climate, Enjoyment, and Physical Competence Perceptions in Finnish Team Sport Athletes: A Prospective and Retrospective Study.

Despite the high rates of participation in sports clubs among Finnish youth, only a few reach elite levels. This study investigated a number of motivational factors, enjoyment, and perceived physical competence perceptions of Finnish youth athletes in their adolescence and then four years later to help understand determinants of elite level attainment. The sample consisted of 824 young athletes born in 1995, who were playing soccer, ice hockey, or basketball in the Finnish sports club system. As youths, participants completed measurements of the perceived task and ego climates, task and ego goal orientations, autonomous and controlled motivations, amotivation, sport enjoyment, and perceived physical competence. Retrospectively, the same participants completed measurements of task, ego, social relatedness, and autonomy supportive climates four years later. All variables were compared to self-reported elite status attainment. Additionally, we examined some demographic characteristics. Prospectively, the self-reported elite athletes (n = 79) reported significantly (p < 0.05) higher perceptions of a task climate, perceived physical competence, sport enjoyment, and autonomous motivation and a lower level of amotivation compared to nonelite athletes. The meaningfulness (Hedges' g) of the significant differences ranged from small to moderate. Retrospectively, elite athletes indicated significantly (p < 0.05) higher perception of a task climate and a social relatedness climate during their sporting career. Hedges' g ranged from moderate to large in meaningfulness. The findings highlighted the importance of focusing on the positive aspects surrounding elite athletes' perceptions to promote youth athletes' development, while not discounting the importance of physical size and talent.

Development and validation of the Perceived Game-Specific Soccer Competence Scale.

The objective of this study was to create a valid, self-reported, game-specific soccer competence scale. A structural model of perceived competence, performance measures and motivation was tested as the basis for the scale. A total of 1321 soccer players (261 females, 1060 males) ranging from 12 to 15 years (13.4 ± 1.0 years) participated in the study. They completed the Perceived Game-Specific Soccer Competence Scale (PGSSCS), self-assessments of tactical skills and motivation, as well as technical and speed and agility tests. Results of factor analyses, tests of internal consistency and correlations between PGSSCS subscales, performance measures and motivation supported the reliability and validity of the PGSSCS. The scale can be considered a suitable instrument to assess perceived game-specific competence among young soccer players.

Development of perceived competence, tactical skills, motivation, technical skills, and speed and agility in young soccer players.

The objective of this 1-year, longitudinal study was to examine the development of perceived competence, tactical skills, motivation, technical skills, and speed and agility characteristics of young Finnish soccer players. We also examined associations between latent growth models of perceived competence and other recorded variables. Participants were 288 competitive male soccer players ranging from 12 to 14 years (12.7 ± 0.6) from 16 soccer clubs. Players completed the self-assessments of perceived competence, tactical skills, and motivation, and participated in technical, and speed and agility tests. Results of this study showed that players' levels of perceived competence, tactical skills, motivation, technical skills, and speed and agility characteristics remained relatively high and stable across the period of 1 year. Positive relationships were found between these levels and changes in perceived competence and motivation, and levels of perceived competence and speed and agility characteristics. Together these results illustrate the multi-dimensional nature of talent development processes in soccer. Moreover, it seems crucial in coaching to support the development of perceived competence and motivation in young soccer players and that it might be even more important in later maturing players.

The incidence of stress symptoms and heart rate variability during sleep and orthostatic test.

This study examined the relation of self-reported stress to cardiac autonomic modulation in real-life conditions. The participants for the study were healthy male (N = 59) and female (N = 40) employees (age 40 ± 10 years). A single-item question and a 14-item questionnaire on perceived stress were administered to the participants before the experimental night. RR-intervals (RRI) were recorded during night sleep and an orthostatic test after awakening at home. The RRI data were analyzed for heart rate (HR) and heart rate variability (HRV) in time and frequency domains. Nocturnal urinary stress hormone (cortisol, adrenal and noradrenal) secretion was also analyzed. Based on the self-reported stress, the participants were divided into either low or high stress group. The results showed that higher incidence of stress symptoms was significantly associated with lower HRV in the orthostatic test regardless of age and gender. Differences between the stress groups in HRV indices were approximately 20-50 and 30-75% in supine and standing positions, respectively. No difference was found in nocturnal HR, HRV, or stress hormone secretion between the stress groups. Higher incidence of stress symptoms was significantly associated with greater decrease of HRV from night sleep to the orthostatic test, as a response to awakening. In conclusion, the present findings support the view that autonomic modulation measured in the orthostatic test, but not during night sleep, is related to self-reported stress.

Heart rate variability and stress hormones in novice and experienced parachutists anticipating a jump.

INTRODUCTION: Chronic work stress and overtraining are known to influence heart rate (HR) and heart rate variability (HRV) at rest and decreased nocturnal HRV is associated with cardiovascular health and disease. The purpose of this study was to examine whether anticipation of an acute highly stressful event influences HR and HRV during the night and morning. METHODS: Nocturnal HR and HRV and urinary stress hormones (cortisol, adrenaline, noradrenaline) as well as HR and HRV responses to an orthostatic test on the morning of a parachute jump day or control day were analyzed from 14 novice and 7 experienced parachute jumpers. RESULTS: There were no differences in any HRV indices during the night or the orthostatic test between the jump and control situations. The novices had higher HR than experienced jumpers in the orthostatic test in the morning and also during the jump, but no differences were found between the groups in nocturnal HR and HRV indices or HRV indices during the orthostatic test. There were no differences in nocturnal stress hormone secretions except slightly elevated adrenaline secretion during the jump night compared to the control night (P = 0.014). CONCLUSIONS: The parachute jump did not substantially influence HR, HRV, or stress hormones during the night or the orthostatic test in the morning preceding the jump. The results suggest that the parachute jump as an acute highly stressful event had no anticipatory effect on autonomic modulation of the heart even though both the novices and experienced jumpers had markedly accentuated sympathetic activation during the parachuting.

Heart rate variability during night sleep and after awakening in overtrained athletes.

PURPOSE: This study was conducted to test the hypothesis of autonomic imbalance in overtrained athletes during sleep and after awakening with analyses of heart rate variability (HRV) and nocturnal urine stress hormones. METHODS: We examined 12 athletes diagnosed to be severely overtrained (OA, 6 men and 6 women, mean age (+/-SD) 25 +/- 7 yr) and 12 control athletes (CA, 6 men and 6 women, mean age 24 +/- 5 yr). Overtraining diagnosis was further supported by higher perceived stress in OA than in CA (24.8 +/- 10.8 vs 15.3 +/- 5.5, P < 0.05). HRV was analyzed with time and frequency domain methods from RR intervals (RRI) recorded during sleep and after awakening. Nocturnal urine stress hormones were analyzed by liquid chromatography. RESULTS: No differences were found in HRV or stress hormones during night sleep. After awakening, the standard deviation of RRI (84 +/- 31 vs 116 +/- 41 ms, P < 0.05) and low-frequency power of RRI (2153 +/- 2232 vs 4286 +/- 2904 ms, P < 0.05) were lower in OA than in CA. From sleep to after awakening, the coefficient of variation of RRI decreased more in OA than in CA (from 11.8 +/- 3.3 to 7.7 +/- 2.5%, P < 0.001 vs from 11.9 +/- 1.8 to 10.0 +/- 2.5%, P < 0.01, respectively, interaction P < 0.05). CONCLUSION: The present findings suggest that in OA, cardiac autonomic modulation is at the level of control athletes during sleep, but the parasympathetic cardiac modulation is slightly diminished after awakening. Further investigations should concentrate on autonomic responses to different challenges, such as awakening in the present study.

The effects of augmented kinematic feedback on motor skill learning in rifle shooting.

In this study, we examined the effects of augmented kinematic knowledge of performance (KP) on shooting performance and learning. Knowledge of performance described the aiming trajectory of the rifle barrel. The effects of knowledge of performance were evaluated in terms of shooting accuracy (shooting score), variability of the shooting score (root mean square error) and rifle stability (x- and y-deviation of rifle movement). The participants (n = 40) were randomly assigned to one of four groups: no-KP, 50% KP, 100% KP and a control group. The three experimental groups performed 480 shots during a 4 week acquisition phase in which feedback was provided. No-feedback retention tests were administered at 2 and 10 days after acquisition. There were no differences between groups during acquisition. In the 2 day retention test, the mean shooting score of the group receiving 100% knowledge of performance was significantly higher than that of the other groups. Furthermore, variability in shooting score for the 100% KP group was lower than that for the 50% KP and control groups. No significant differences were found in rifle stability between the experimental groups. In summary, a high frequency of kinematic knowledge of performance improved shooting accuracy, but the effect appeared to be temporal, disappearing in the 10 day retention test. Given that a parallel effect was not found in rifle stability, future research should focus on examining the reasons for this improvement in shooting score.

Timing of triggering in relation to the cardiac cycle in nonelite rifle shooters.

This study investigated the timing of the trigger pull in relation to the cardiac cycle during air rifle shooting. Electrocardiogram) was recorded from 20 male nonelite rifle shooters in two separate testing sessions. The testing was conducted at an indoor shooting range using an optoelectronic shooting system. Each participant fired a shot in the standing position at a distance of 10 m from the target. The results showed that compared to random triggering, the shooters fired more often during the phase of 10-50% of the R wave-to-R wave (R-R) interval and less often during the phase of 50-90%. With regard to performance accuracy, the participants exhibited average or above average performance, when the shot occurred in the beginning (0-50%) and in the end (70-99%) of the R-R interval. The less optimal range for the triggering was located within the 50-70% phase of the R-R interval. The length of R-R interval (i.e., heart rate) did not affect the relation of shot placement within the cardiac cycle to the accuracy of shooting performance. The present results extend previous findings by showing that in air rile shooting the optimum firing time within the cardiac cycle may be located in the systolic phase. It is argued that the systole-diastole dichotomy is not a sufficiently accurate way to investigate the effects of shot placement in the cardiac cycle. Further research is needed to examine the extent to which the relationship between the timing of triggering within the cardiac cycle and shooting performance depends a shooter's skill level.

Brain Slow Potentials and Postural Sway Behavior During Sharpshooting Performance.

In the present study, the relation of preparatory brain slow potentials (SPs) to postural body sway during sharpshooting performance was examined. SPs from frontal, left-central, and right-central areas were recorded from 6 elite and 6 non-elite sharpshooters during a realistic simulated shooting task. A force platform technique was used in the recording of postural sway. The results showed that body sway, as indexed by sway amplitude and mean velocity, was associated with the concomitant SP changes. That relationship was dependent on the shooter's expertise level, however. The main finding among the elite shooters was that the reduced amplitude of body sway coincided with reduced frontal positivity, whereas in the non-elite shooters, the amplitude of sway and the mean sway velocity in the anteroposterior direction were typically accompanied by the lateralization of central negativity. Those findings offer some new insights for evaluating the functional significance of preparatory brain SPs associated with psychomotor processing in sharpshooting. The results from the present study also have implications for the understanding of the postural strategies employed by shooters of different expertise levels.