Corrigendum: Effect of neuromuscular training program on quality of life after COVID-19 lockdown among young healthy participants: A randomized controlled trial.

[This corrects the article DOI: 10.3389/fpsyg.2022.844678.].

The Influence of Transcranial Direct Current Stimulation on Shooting Performance in Elite Deaflympic Athletes: A Case Series.

Transcranial direct current stimulation (tDCS) has been shown to improve motor learning in numerous studies. However, only a few of these studies have been conducted on elite-level performers or in complex motor tasks that have been practiced extensively. The purpose was to determine the influence of tDCS applied to the dorsolateral prefrontal cortex (DLPFC) on motor learning over multiple days on 10-m air rifle shooting performance in elite Deaflympic athletes. Two male and two female elite Deaflympic athletes (World, European, and National medalists) participated in this case series. The study utilized a randomized, double-blind, SHAM-controlled, cross-over design. Anodal tDCS or SHAM stimulation was applied to the left DLPFC for 25 min with a current strength of 2 mA concurrent with three days of standard shooting practice sessions. Shooting performance was quantified as the points and the endpoint error. Separate 2 Condition (DLPFC-tDCS, SHAM) × 3 Day (1,2,3) within-subjects ANOVAs revealed no significant main effects or interactions for either points or endpoint error. These results indicate that DLPFC-tDCS applied over multiple days does not improve shooting performance in elite athletes. Different stimulation parameters or very long-term (weeks/months) application of tDCS may be needed to improve motor learning in elite athletes.

Effect of Neuromuscular Training Program on Quality of Life After COVID-19 Lockdown Among Young Healthy Participants: A Randomized Controlled Trial.

Study in the period of coronavirus disease 2019 (COVID-19) lockdown and the effect of different exercise training programs on the quality of life (QoL) dimension are limited. This randomized control study as a part of which the impact of an 8-week neuromuscular training program on the 90 healthy young individuals' QoL after COVID-19 lockdown was assessed using a short form of the WHOQOL-BREF questionnaire comprising of four domains (physical health, psychological health, social relations, and the environment). The intervention group (NT) (n = 47) took part in a neuromuscular training program consisting of dynamic neuromuscular stabilization and whole-body vibration training. In contrast, the control group (CG) (n = 43) did not participate in any programmed physical activity. From pre- to post-intervention test, the NT group significantly and substantially improved [mean change (95% CI)] all the QoL domains, physical for 12.78 scores (8.89, 16.64), psychological for 13.12 scores (9.51, 16.74), social relationships for 20.57 scores (16.12, 25.02), and environmental for 24.40 scores (21.45, 27.35). These results suggest that the NT program could enhance QoL in young and healthy participants following COVID-19 lockdown.

The effects of daily physical activity intervention on physical fitness in preschool children.

The study aimed to determine the effects of 6 months daily physical activity on physical fitness in preschool children. A total of 72 children (36 boys) and 92 children (47 boys) composed the experimental (EG) and control group (CG), respectively. We used the PREFIT battery access physical fitness. In EG, participants had 45 minutes of organized physical activity 5 days per week. The CG continued their usual routine with 30 minutes of structured physical activity two times per week. The EG improved the mean performance of grip strength (η p2=0.08) and sit-ups in the 30s ( p2=0.16) to a significantly greater extent as compared to the CG. In boys, the improvements of mean performance of handgrip strength (η p2=0.13), 4x10m shuttle run η p2=0.09), standing long jump (η p2=0.05), sit-ups in 30s (η p2=0.17) were significantly greater in EG than in the CG. However, girls in EG only had significant improvements  in the sit-ups in the 30 s test compared to CG (η p2=0.14). Overall, our study shows that after 6 months of daily exercise programme, preschool children improved muscular strength compared to those peers allocated in the control group. No significant differences between groups were found in the remaining fitness components analysed.

Intensity-Modified Recreational Volleyball Training Improves Health Markers and Physical Fitness in 25-55-Year-Old Men.

The present study is aimed at determining the effects of intensity-modified recreational volleyball training on health markers and physical fitness in healthy middle-aged men. Thirty-four healthy untrained men aged 25-55 years were randomized to either a modified recreational volleyball group (MRV, n = 17) or a recreational volleyball group (RV, n = 17). Both groups performed volleyball training twice a week over 12 weeks, with participants in MRV playing a modified game with higher intensity due to shorter breaks between rallies. The small to moderate improvements of both groups were observed in SBP (MRV g av = -0.50 [-0.67, -0.33] vs. RV g av = -0.37 [-0.55, -0.20]) to a similar extent (p = 0.12). However, only the MRV significantly improved (p < 0.001) the mean body weight (g av = -0.35 [-0.52, -0.18]) and BMI (g av = -0.39 [-0.56, -0.22]) to a moderate extent and the YYIR1 performance (g av = 2.45 [2.22, 2.69]) to a large extent. Even though both groups significantly improved the rest HR, the mean change of rest HR was significantly greater in MRV as compared to the RV (p < 0.001, ŋ p 2 = 0.47). The study revealed that an intensity-modified type of recreational volleyball, involving shorter breaks between rallies, improves cardiorespiratory fitness and health markers for men aged 25-55 years.

Body Composition in Elite Soccer Players from Youth to Senior Squad.

There is a strong relationship between body composition and performance in male soccer players. This study aimed to display an optimal body height and weight, and body composition profile of male soccer players for four competitive age groups. This cross-sectional study included four groups: U-15 (n = 152), U-17 (n = 154), U-19 (n = 61), and seniors (n = 27). Body height and weight were measured under standard conditions, and the bioelectrical impedance analyzer (BIA) analyzed body composition. On average, soccer players in the U-15 group had significantly lower body height, weight, body mass index, skeletal muscle mass, fat-free mass, total body water and basal metabolic rate than U-17, U-19 and seniors, but a higher percentage of body fat than U-17 and U-19, p < 0.05. In addition, the results show significant non-linear increases in body height, weight and body composition as the age of soccer players increases, with the exception of the percentage of body fat mass, which tends to significantly decrease with age. The main findings of this study are that body fat mass remains stable and similar across all age groups, including in the senior squad.

Speed, Change of Direction Speed and Reactive Agility in Adolescent Soccer Players: Age Related Differences.

There are a plethora of studies investigating agility in soccer; however, studies have rarely presented the reaction time in differentiating age groups in adolescent soccer players. We investigated age differences in reactive agility, speed, and change of direction speed (CODs), in a group of highly trained adolescent soccer players. A total of 75 adolescent male soccer players (aged 14-19 years) were recruited. The players were grouped based on their age to under 15 (U15; n = 27), under 17 (U17; n = 25), and under 19 (U19; n = 23) players. Players were tested for 5 m, 10 m, and 20 m sprint, CODs speed test, Illinois test, and reactive agility test (total and reaction time). Only the reactive agility test with a live tester (RAT live) and RAT live reaction time (RAT live RT) distinguished U19 from both groups, U17 (RAT live, p < 0.01; RAT RT live, p < 0.01) and U15 (RAT live, p < 0.01; RAT RT live, p < 0.01). Groups did not have different times for 5 m sprint, RAT light and RAT RT light, F = 0.472, 2.691, 1.023, respectively, p > 0.05. Moreover, a significantly slower average performance of sprint 20, CODs left and right, and Illinois was also observed in U15 as compared to U17 and U19 (p < 0.05). We can conclude that results in agility tests that include live testers can be a significant factor that differentiates between adolescent soccer players considering their age.

Effect of Integrated Neuromuscular Exercise in Physical Education Class on Health-Related Fitness in Female Children.

Integrated neuromuscular training (INT) showed benefits for improving fundamental movement skills (FMS). However, the INT health-related fitness (HRF) effects are lacking. The current study aimed to determine the effects of INT implemented during physical education (PE) in a primary school in the Republic of Serbia on HRF in female children. The sample consisted of 72 healthy girls who were divided into the intervention (EG: n = 37; mean ± SD: age = 8.17 ± 0.31) and control (CG: n = 35; age = 8.11 ± 0.31) groups. The EG and CG performed the INT program and traditional PE activities two times per week within the first ~15 min of PE class, respectively. The Fitnessgram battery tests assessed the HRF (body composition, cardiorespiratory endurance, muscular fitness, and flexibility) before and after the program. After eight weeks, the EG significantly reduced all fat measures, while the CG decreased only triceps skinfold but to a smaller extent (F = 5.92, p < 0.02, ŋ2 = 0.09). Both groups significantly improved the performance of almost all muscular fitness tests (curl-ups, trunk lift, push-ups); however, the EG increased the push-ups more than the CG (F = 9.01, p < 0.01, ŋ2 = 0.14). The EG additionally improved the modified pull-ups (F = 14.09, p < 0.01, ŋ2 = 0.19) and flexed arm hang (F = 28.82, p < 0.01, ŋ2 = 0.33) tests. The flexibility and cardiorespiratory endurance of both groups did not significantly change after eight weeks. This approach of exercise showed positive acceptance and relatively good results after only eight weeks.

Relationship between Motor Competence, Physical Fitness, and Academic Achievement in Young School-Aged Children.

Children in schools are facing many academic challenges. Moreover, there is constant pressure on children and parents to maximize academic achievement. We aimed to determine the relationship between motor competence, physical fitness, and academic achievement in young school-aged children. Participants were 130 elementary school children (mean ± SD8.60 ± 0.61 years; 51 boys and 79 girls) from Serbia. The KTK (Körperkoordinations Test für Kinder) battery of tests was used to assess the motor competence in children; children' physical fitness was assessed using the EUROFIT battery of tests, while academic achievement was assessed based on the children's GPA (grade point average) scores at the end of the school year. Pearson's r showed the weak to moderate relationships between the GPA and motor competence and physical fitness measures. The GPA correlates positively and significantly with almost all motor competence and physical fitness measures, but negatively with BMI (p ≤ 0.05). However, the hierarchical linear regression indicated only the plate tapping and sit and reach as the significant predictors of the GPA. Although both tests positively affect the GPA, the plate tapping (B = -0.22, p = 0.02) tends to influence the GPA more than the sit and reach test (B = 0.18, p = 0.04) after adjusting for effects of motor competence (B = 0.19, p = 0.03), age (B = -0.01, p = 0.89), and BMI (B = -0.19, p = 0.03). This study provides evidence demonstrating that academic achievement is generally associated with physical fitness and motor competence in children. However, plate taping and sit and reach were accounted as the most important predictors for academic achievement.

Short-Term Core Strengthening Program Improves Functional Movement Score in Untrained College Students.

Functional movement is an important part of developing athletes' but also untrained individuals' performance. Its monitoring also proved useful in identifying functional limitations and asymmetries, and also in determining the intervention effects. The quasi-experimental pre-test post-test study investigated the effects of core stability training program on the Functional Movement Screen (FMS) score in untrained students after six weeks. The intervention (INT) and control (CG) groups included 73 and 65 male students, respectively. Functional movement patterns were evaluated using the FMS including seven components scores representing seven basic functional patterns. Both groups significantly improved almost all FMS components scores, but the INT increased the mean performance of the hurdle step (partial ŋ2 × 100 = 4%, p = 0.02), in-line lunge (partial ŋ2 × 100 = 3%, p = 0.05), rotatory stability (partial ŋ2 × 100 = 4%, p = 0.02) and total FMS (partial ŋ2 × 100 = 3%, p = 0.04) significantly more than the CG. This justifies that core strengthening can improve FMS in untrained individuals even with the short duration programs.

Anthropometric and Motor Competence Classifiers of Swimming Ability in Preschool Children-A Pilot Study.

Swimming is a form of physical activity and a life-saving skill. However, only a few studies have identified swimming ability classifiers in preschool children. This pilot cross-sectional study aimed to find anthropometric (AM) and motor competence (MC) predictors of swimming ability in preschool children, by building classifiers of swimming ability group (SAG) membership. We recruited 92 children (girls n = 45) aged 5-6 years and took the AM and MC measurements in accordance with the reference manual and using the KTK battery test (motor quotient, MQ), respectively. A linear discriminant analysis tested a classification model of preschoolers' swimming ability (SAG: POOR, GOOD, EXCELLENT) based on gender, age, AM, and MC variables and extracted one significant canonical discriminant function (model fit: 61.2%) that can differentiate (group centroids) POOR (-1.507), GOOD (0.032), and EXCELLENT (1.524). The MQ total was identified as a significant classifier, which absolutely contributed to the discriminant function that classifies children's swimming ability as POOR (standardized canonical coefficient: 1.186), GOOD (1.363), or EXCELLENT (1.535) with an accuracy of 64.1%. Children with higher MQ total ought to be classified into higher SAG; thus, the classification model of SAG based on the MQ total is presented.

Evaluation of Gross Motor Coordination and Physical Fitness in Children: Comparison between Soccer and Multisport Activities.

The early detection and continuous monitoring of children's motor competence levels and physical fitness is very important. The purpose of this study was to determine the differences in motor coordination of children enrolled in soccer and multisport activities. The participants of this study included 147 boys and girls (mean age 7.60 ± 0.85 years). The total sample of subjects was composed of two subgroups: children who were enrolled in organized exercise programs-multisports (n = 77), and children who were engaged in soccer training (n = 70). Motor coordination was evaluated with the Kiphard-Schilling body coordination test (KTK). Physical fitness was assessed with a 20 m shuttle run test, 4 × 10 m shuttle run test, standing long jump, and handgrip strength. The ANCOVA showed significant differences (p < 0.05) with large effect size between groups for tests hopping for height (d = 0.93), total motor quotient (d = 1.31), jumping sideways (d = 1.32), and moving sideways (d = 1.59), after adjusting for age and gender. There were no significant differences between groups in the physical fitness tests. It can be concluded that children enrolled in multisport activities have higher levels of motor coordination than children who are enrolled only in soccer. Therefore, multiple sport training programs should be considered and encouraged by parents, educators, and other training professionals.

Nine Months of a Structured Multisport Program Improve Physical Fitness in Preschool Children: A Quasi-Experimental Study.

Research in preschool children that investigates the impact of different exercise interventions on physical fitness is limited. This pre-post study was aimed at determining if participation in a nine-month structured multisport program (MSG; n = 38) could enhance physical fitness components compared to a formal exercise program (control group (CG); n = 36) among preschool children. Physical fitness was assessed using standardized tests (the standing long jump, sit and reach, 20 m sprint, sit-ups for 30 s, bent-arm hang, medicine ball throw (MBT), grip strength, 4 × 10 m shuttle run, and 20 m shuttle run tests). The structured multisport program involved fundamental/gross and fine motor skills and ball game-based exercises twice a week. The control group was free of any programmed exercise except for the obligatory program in kindergartens. A mixed ANOVA demonstrated significant group-by-time interaction effects for the 4 × 10 m shuttle run, standing long jump, sit-ups, bent-arm hang, grip strength, and sit and reach tests (p < 0.05). There was no significant group-by-time interaction effect for the 20 m sprint test (p = 0.794) or for the 20 m shuttle run test (p = 0.549). Moreover, the MSG and CG performance in the MBT and 20 m shuttle run tests improved to a similar extent from pre- to post-test. Our results indicate that compared to the formal plan, the structured multisport program led to a sustained improvement in physical fitness in healthy 5-to-6-year old children.

Eight months of school-based soccer improves physical fitness and reduces aggression in high-school children.

School-based programmes have shown promising results in the reduction of aggressive behaviour, but the effectiveness of physical activity modalities among adolescents remains to be determined. The aim of this study was to determine the effects of a school-based soccer programme on physical fitness and aggression in adolescent students. One hundred and five high school students were randomized to a small-sided soccer training group (SG) or a control group (CG). In addition to the regular physical education classes performed as part of a curriculum, the SG completed eight months of small-sided soccer training twice a week after school. Aerobic fitness (YYIR1), vertical jump (VJ), backward overhead medicine ball throw (BOMBT), and Buss and Perry's aggression questionnaire were evaluated before and after eight months of training. Greater improvements were observed in the SG than in the CG in the BOMBT (%diff=4.3, ŋp 2=.308) and YYIR1 tests (%diff=2.2, ŋp 2=.159), and physical aggression subscale (%diff=-12.1, ŋp 2=.144). Extra, school-based recreational soccer for adolescents was accompanied by a significant improvement in physical fitness, compared to physical education classes only. Moreover, the implementation of recreational soccer into regular physical education classes seems to be a potentially appropriate stimulus for reducing aggression in high-school students.

Short-Term FIFA 11+ Improves Agility and Jump Performance in Young Soccer Players.

Studies dealing with the effectiveness of the Fédération Internationale de Football Association (FIFA) 11+ prevention program to improve performance outcomes in children aged < 14 years are limited. This study aimed to point out the effects of the application of short-term FIFA 11+ warm-up program on physical performance in young football players. Participants were 36 youth male football players, divided into a FIFA 11+ (n = 19; mean (SD) age: 11.15 (0.79) y) and a control group (CG: n = 17; age: 10.87 (0.8) y) and trained for 4 weeks. Before and after the training period, standing long jump performance, agility, repeated sprint ability, sit and reach, and "30-15" intermittent fitness tests were assessed. A mixed ANOVA showed significant differences between the groups in the standing long jump test (FIFA 11+: 5.6% vs. CG: -1.9%) in favor of FIFA 11+ over CG. Additionally, the FIFA 11+ performance of the Illinois agility test was significantly better compared to the CG performance (FIFA 11+: -1.9% vs. CG: 0.03%). The main findings of this study suggest that just 4 weeks of implementation of the FIFA 11+ improves physical performance compared with traditional warm-up routines in young soccer players.