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1.
Biol Sport ; 41(3): 3-13, 2024 Jul.
Article in English | MEDLINE | ID: mdl-38952905

ABSTRACT

Maturity status and relative age are two of the determining factors in talent development. The aim of the study was to analyze the influence of biological maturity status and relative age on physical performance in young male and female handball players. The sample included 48 males (14.11 ± 1.17 years) and 41 females (14.25 ± 1.64 years) players from one Spanish professional handball academy. Anthropometric data (height, sitting height, body mass and self-reported biological parent heights) and physical performance data (CMJ, DJ, 20 m speed, T-test and throwing velocity) were collected. Biological maturity status was determined as the percentage of predicted adult height, while relative age was estimated in birth quartiles based on biennial age grouping (Q1-Q8). The results showed a positive correlation between maturity status and CMJ in male players (p < 0.01). Differences in CMJ performance according to maturity status were identified (p < 0.05), with higher jump heights being recorded especially in early maturing boys (p < 0.01) and first lines and wings (p < 0.05). The variance in CMJ test scores could be explained by the maturity status by 42.90% in U-15 (p < 0.05) and 72.60% in U-16 male players (p < 0.001). By contrast, no differences were found in girls (p > 0.05). Moreover, no relationships were found between relative age and indices of physical performance (p > 0.05). Overall, maturity status had greater impacts on the tests of physical performance than relative age. Stakeholders should monitor the maturity status of young handball players to avoid physical performance biases that do not allow them to develop their sporting potential.

2.
J Hum Kinet ; 90: 45-56, 2024 Jan.
Article in English | MEDLINE | ID: mdl-38380311

ABSTRACT

Backstroke swimmers display the greatest contribution of underwater kicking during the swimming race distances, but, surprisingly, there is little evidence of how kicking kinematics in the dorsal position should be performed. The aim of the present study was to examine the kinematic characteristics of competitive swimmers during underwater undulatory swimming in the dorsal position, with special attention to the swimmers' gender, the level of skill, and kick order. Forty-one national-level swimmers (27 females and 14 males) were filmed from an underwater lateral view while performing a 25-m backstroke from a push start, and they were divided into fast and slow groups according to their kicking velocity. Direct linear algorithms were employed to reconstruct the two-dimensional kinematic characteristics of the first and final kicks of the underwater section. There were no differences between males and females in kicking performance when data were normalised to the swimmers' height. However, swimmers in the fast-kicking group were distinguished by a greater kicking frequency (η2: 0.15) and specific segmental kinematics related to a lower knee range of motion. Swimmers decreased kicking velocity (η2: 0.47) in addition to the kicking frequency (η2: 0.31) and length (η2: 0.16), but increased the kicking amplitude (η2: 0.11) between the first and the final kicks. Changes in kicking segmental kinematics were more related to modification in body orientation during the underwater trajectory than to the kicking motion itself. These results provide the first solid evidence of how swimmers should kick for better performance in dorsal underwater swimming.

3.
J Exp Bot ; 75(1): 364-390, 2024 Jan 01.
Article in English | MEDLINE | ID: mdl-37712879

ABSTRACT

The mechanisms underlying susceptibility to and defense against Pseudomonas syringae (Pph) of the common bean (Phaseolus vulgaris) have not yet been clarified. To investigate these, 15-day-old plants of the variety Riñón were infected with Pph and the transcriptomic changes at 2 h and 9 h post-infection were analysed. RNA-seq analysis showed an up-regulation of genes involved in defense/signaling at 2 h, most of them being down-regulated at 9 h, suggesting that Pph inhibits the transcriptomic reprogramming of the plant. This trend was also observed in the modulation of 101 cell wall-related genes. Cell wall composition changes at early stages of Pph infection were associated with homogalacturonan methylation and the formation of egg boxes. Among the cell wall genes modulated, a pectin methylesterase inhibitor 3 (PvPMEI3) gene, closely related to AtPMEI3, was detected. PvPMEI3 protein was located in the apoplast and its pectin methylesterase inhibitory activity was demonstrated. PvPMEI3 seems to be a good candidate to play a key role in Pph infection, which was supported by analysis of an Arabidopsis pmei3 mutant, which showed susceptibility to Pph, in contrast to resistant Arabidopsis Col-0 plants. These results indicate a key role of the degree of pectin methylesterification in host resistance to Pph during the first steps of the attack.


Subject(s)
Arabidopsis , Phaseolus , Arabidopsis/genetics , Arabidopsis/metabolism , Phaseolus/genetics , Phaseolus/metabolism , Carboxylic Ester Hydrolases/genetics , Carboxylic Ester Hydrolases/metabolism , Pseudomonas syringae/physiology , Pectins/metabolism , Cell Wall/metabolism
4.
Sports (Basel) ; 11(8)2023 Aug 18.
Article in English | MEDLINE | ID: mdl-37624140

ABSTRACT

Emotional intelligence is a determinant factor in sports performance. The present study analysed differences in total emotional intelligence and its four dimensions in 2166 Spanish athletes (25.20 ± 10.17 years) from eight sports (volleyball, track and field, shooting, football, basketball, handball, gymnastics, and judo). A total of 1200 men and 966 women answered anonymously using a Google Forms questionnaire sent via WhatsApp about demographics and psychological variables. A Pearson correlation was conducted to assess the age-emotional intelligence relationship. An independent T-test and One-Way ANOVA were carried out to check for age differences between biological sex and sport and a One-Way ANCOVA to determine differences between sports controlled by age. Age differences were observed by sex and sport (p < 0.001). An association was found between age and emotional intelligence dimensions (p < 0.001), except for other's emotional appraisal (p > 0.05). Judo was the sport with the highest levels of regulation of emotions, other's emotional appraisal, use of emotion, and total emotional intelligence (p < 0.05). Generally, emotional intelligence was found to be more developed in individual sports than in team sports, except football. Consequently, psychological skills like emotional intelligence could be critical to achieving high performance, depending on the sport.

5.
Sensors (Basel) ; 23(15)2023 Jul 27.
Article in English | MEDLINE | ID: mdl-37571498

ABSTRACT

Performance analysis based on artificial intelligence together with game-related statistical models aims to provide relevant information before, during and after a competition. Due to the evaluation of handball performance focusing mainly on the result and not on the analysis of the dynamics of the game pace through artificial intelligence, the aim of this study was to design and validate a specific handball instrument based on real-time observational methodology capable of identifying, quantifying, classifying and relating individual and collective tactical behaviours during the game. First, an instrument validation by an expert panel was performed. Ten experts answered a questionnaire regarding the relevance and appropriateness of each variable presented. Subsequently, data were validated by two observers (1.5 and 2 years of handball observational analysis experience) recruited to analyse a Champions League match. Instrument validity showed a high accordance degree among experts (Cohen's kappa index (k) = 0.889). For both automatic and manual variables, a very good intra- ((automatic: Cronbach's alpha (α) = 0.984; intra-class correlation coefficient (ICC) = 0.970; k = 0.917) (manual: α = 0.959; ICC = 0.923; k = 0.858)) and inter-observer ((automatic: α = 0.976; ICC = 0.961; k = 0.874) (manual: α = 0.959; ICC = 0.923; k = 0.831) consistency and reliability was found. These results show a high degree of instrument validity, reliability and accuracy providing handball coaches, analysts, and researchers a novel tool to improve handball performance.


Subject(s)
Artificial Intelligence , Sports , Reproducibility of Results , Surveys and Questionnaires
6.
Article in English | MEDLINE | ID: mdl-37510637

ABSTRACT

The impact that occurs on the runner's foot when it lands on the ground depends on numerous factors: footwear, running technique, foot strike and landing pattern, among others. However, the surface is a decisive factor that can be selected by the runner to improve their sports practice, thereby avoiding injuries. This study aimed to assess the number and magnitude of accelerations in impact (produced by the runner when their foot strikes the ground) on three different surfaces (grass, synthetic track, and concrete) in order to know how to prevent injuries. Thirty amateur runners (age 22.6 ± 2.43 years) participated in the study. They had to run consecutively on three different surfaces at the same speed, with a three axis-accelerometer placed on the sacrum and wearing their own shoes. The results showed that the running impacts differed based on the type of surface. Higher mean acceleration (MA) and mean peak acceleration (PA) in the impacts were observed on concrete compared to the other two surfaces. There were small differences for MA: 1.35 ± 0.1 g (concrete) vs. 1.30 ± 0.1 g (synthetic track) SD: 0.43 (0.33, 0.54) and 1.30 ± 0.1 g (grass) SD: 0.36 (0.25, 0.46), and small differences for PA: 3.90 ± 0.55 g (concrete) vs. 3.68 ± 0.45 g (synthetic track) SD 0.42 (0.21, 0.64) and 3.76 ± 0.48 g (grass) SD 0.27 (0.05, 0.48), implying that greater impacts were produced on concrete compared to synthetic track and grass. The number of peaks of 4 to 5 g of total acceleration was greater for concrete, showing small differences from synthetic track: SD 0.23 (-0.45, 0.9). Additionally, the number of steps was higher on synthetic track (34.90 ± 2.67), and small differences were shown compared with concrete (33.37 ± 2.95) SD 0.30 (-0.25, 0.85) and with grass (35.60 ± 3.94) SD 0.36 (-0.19, 0.91). These results may indicate a change in technique based on the terrain. Given the increasing popularity of running, participants must be trained to withstand the accelerations in impact that occur on different surfaces in order to prevent injuries.


Subject(s)
Acceleration , Foot , Humans , Young Adult , Adult , Biomechanical Phenomena , Shoes , Poaceae
7.
Int J Sports Med ; 44(12): 871-881, 2023 Nov.
Article in English | MEDLINE | ID: mdl-37524114

ABSTRACT

The purpose of this study was to evaluate young male and female handball players' perceptions of the bio-banding concept. The estimated biological maturity status was assessed in a sample of 46 male and 40 female handball players (aged 14.06±1.40 years), who competed in both an annual age-group and bio-banded tournament. To test the players' perception of bio-banding, a post-competition questionnaire was conducted. A series of ANOVA and one-sample t-tests were used in order to examine the differences in perception between the different maturity groups. An inductive thematic analysis of the qualitative data recorded in the open-ended questions was also carried out. The results showed that early-maturing boys enjoyed the bio-banding tournament more than late-maturing boys (p<0.05). Conversely, no differences were found in girls (p>0.05). Furthermore, discussions were conducted based on the qualitative analysis of the players' written comments regarding their overall experience, finding individual variance in biological maturity may be less relevant in female sports contexts due to gender-related differences. Thus, a greater influence on play and leadership in late maturing boys and early maturing girls, a greater physical challenge in early maturing boys and an opportunity to express themselves technically and tactically in late maturing boys and on-time maturing girls were observed. Therefore, stakeholders must consider the different consequences of bio-banding in order to maximize the athlete's sport development process.


Subject(s)
Sports , Humans , Male , Female , Anthropometry/methods , Body Height
8.
Article in English | MEDLINE | ID: mdl-36981742

ABSTRACT

Strength training in prepubertal children is one of the topics that has aroused the most interest and controversy among training professionals in recent years. Therefore, the aim of the present study was to analyze the available scientific evidence on the influence of strength training variables on morphological and/or neuromuscular adaptations in healthy prepubertal populations with no previous experience in this type of training according to the descriptive sample characteristics. According to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis, 22 studies were selected after a systematic search and selection process using four electronic databases: Google Scholar, PubMed, Scopus, and SPORT Discus. Furthermore, the internal validity of the studies included was assessed using the modified PEDro scale. The sample consisted of 604 prepubertal children (age, 10.02 ± 0.75 years), of whom 473 were boys and 131 were girls, with 104 strength training programs recorded. Strength training resulted in a significant increase in jumping (n = 29) and sprinting (n = 13) abilities. Moreover, muscle strength was increased in 100% of the cases. Morphologically, strength training resulted in a decrease in body fat percentage (n = 19) and an increase in lean body mass (n = 17). With regard to gender, increases in general sport skills and basic physical abilities were significant in males but not in females. Thus, the results are more heterogeneous in girls due to the small number of studies carried out. Therefore, this research provides practical applications for coaches to design and implement more effective training programs to maximize adaptations, enhance physical performance, and reduce injury risk.


Subject(s)
Resistance Training , Sports , Male , Female , Humans , Child , Resistance Training/methods , Muscle Strength/physiology , Adaptation, Physiological , Acclimatization
9.
Article in English | MEDLINE | ID: mdl-36834047

ABSTRACT

An understanding of physical demands during official competitions is essential to achieving the highest performance in handball. The aim of this systematic review was to summarise the available scientific evidence associated with physical demands during official competitions in elite handball according to playing positions, competition level and gender. Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, 17 studies were selected after a systematic search and selection process of three digital databases: PubMed, Web of Science and Sport Discus. The quality of the selected studies was evaluated using the Strengthening the Reporting of Observational Studies in Epidemiology checklist; the average score was 18.47 points. The sample consisted of 1175 handball players, of whom 1042 were men (88.68%) and 133 were women (11.32%). The results show that an elite handball player covered on average 3664.4 ± 1121.6 m during a match. The average running pace was 84.8 ± 17.2 m∙min-1. The total distance covered was largely greater in national competitions (4506.7 ± 647.9 m) compared with international competitions (2190.3 ± 1950.5 m) (effect size (ES) = 1.2); however, the running pace did not present any significant difference between the international or national level (ES = 0.06). In regard to gender, the total distance covered was moderately greater in female competitions (4549.1 ± 758.6 m) compared with male competitions (3332.6 ± 1257.7 m) (ES = 0.9), and the running pace was largely greater in female competitions (110.5 ± 7.2 m∙min-1) compared with male competitions (78.4 ± 19.7 m∙min-1) (ES = 1.6). In relation to playing position, backs and wings covered a moderately greater total distance (ES = 0.7 and 0.6) and slightly more meters per minute (ES = 0.4 and 0.2) than pivots. Moreover, the technical activity profile differed between playing positions. Backs performed moderately more throws than pivots and wings (ES = 1.2 and 0.9), pivots exhibited largely more body contact than backs and wings, and wings performed moderately more fast breaks (6.7 ± 3.0) than backs (2.2 ± 2.3) (ES = 1.8). Therefore, this research study provides practical applications for handball coaches and strength and conditioning professionals with respect to designing and implementing more individualised training programmes to maximise performance and reduce injury risk.


Subject(s)
Athletic Performance , Humans , Male , Female , Anthropometry
10.
Article in English | MEDLINE | ID: mdl-36360619

ABSTRACT

(I) Training in unstable conditions, with different elements, platforms, or situations, has been used because there is a significant increase in muscle activation, balance, proprioception, and even sports performance. However, it is not known how the devices used are classified according to performance variables, nor the differences according to instability experience. (II) This study aims to analyze the differences in power and speed in push-ups with different situations of instability in trained and untrained male subjects. Power and speed in push-up exercise were analyzed in 26 untrained and 25 trained participants in 6 different situations (one stable and five unstable) (1) stable (PS), (2) monopodal (PM), (3) rings (PR), (4) TRX® (PT), (5) hands-on Bosu® (PH) (6) feet on Bosu® (PF). The variables were analyzed using a linear position transducer. (III) The best data were evidenced with PS, followed by PR, PM, PT, PH and PF. The trained subjects obtained better results in all the conditions analyzed in mean and maximum power and speed values (p < 0.001). The decrease in these variables was significantly greater in the untrained subjects than in the trained subjects in the PR situation (8% and 18% respectively). In PF there were differences between groups (p < 0.001), reaching between 32-46% in all variables. The difference between the two groups was notable, varying between 12-58%. (IV) The results showed a negative and progressive influence of instability on power and speed in push-ups. This suggests that instability should be adapted to the subject's experience and is not advisable in untrained subjects who wish to improve power.


Subject(s)
Athletic Performance , Muscle, Skeletal , Humans , Male , Muscle, Skeletal/physiology , Athletic Performance/physiology , Exercise/physiology , Adaptation, Physiological , Muscle Strength/physiology
11.
Article in English | MEDLINE | ID: mdl-36231498

ABSTRACT

The increase of low-cost technology for underwater filming has made quantitative analysis an affordable resource for swimming coaches on a frequent basis. In this context, a synthesis of the kinematic determinants of underwater undulatory swimming (UUS) seems to be lacking. The aim of the present study was to synthesise the scientific evidence on the kinematic characteristics of competitive swimmers during UUS and the main kinematic determinants of UUS performance, as well as to summarise the main methodological considerations for UUS kinematic analysis. A systematic literature search was performed through four electronic databases following the PRISMA guidelines and STROBE for evaluating the quality of the included studies. Twenty-three research studies from the first search and two from the second search were finally considered. In total, 412 competitive swimmers (321 males and 91 females) with a performance standard of international B (11%), national (51%), or regional (35%) level were analysed. Most studies focused on a two-dimensional analysis of the ventral UUS performed from a push start and filmed 6-12 m from the starting wall. Kinematic analysis of UUS included kicking parameters (kicking length, frequency, and amplitude) as well as selected segmental kinematics in 76% of studies and the analysis of UUS performance determinants in 36%. Information about the determinants of UUS performance was inconsistent due in part to inconsistencies in the definition of kinematic parameters. Further research studies where automatic motion capture systems are applied to the analysis of UUS on the aforementioned conditions should be conducted.


Subject(s)
Swimming , Biomechanical Phenomena , Female , Humans , Male , Motion
12.
J Therm Biol ; 109: 103318, 2022 Oct.
Article in English | MEDLINE | ID: mdl-36195386

ABSTRACT

The Infrared Thermography (IRT) is being used in the field of sport as a means of quantifying the effects of workload. The aims of this study were (i) to determine the variations in skin temperature (Tsk) of the lower limbs after an effort of auxotonic and isometric squat contractions using infrared thermography and (ii) to study jumping performance variations in handball players after those two different contraction types. A total of 15 national level handball players voluntarily participated in the study (age: 23.20 ± 5.23 years). Two types of protocols - isometric and auxotonic - were performed on different days, having previously calculated the maximal isometric squat strength and auxotonic 1RM. During the data collection, participants performed a specific standardized warm-up and then randomly performed 4x10 repetitions of auxotonic squat to 90° of knee flexion at 70% of 1RM and 4x10 s of isometric squat effort at 90° of knee flexion, at 70% of maximal isometric squat strength (both with a passive recovery of 90 s seated). Rate of perceived exertion (RPE) and countermovement jumping performance (CMJ) were measured before and immediately after efforts. Additionally, infrared thermography data from twelve regions of interest of the lower limbs were registered before, immediately after and 15 min after finishing the effort. The main results indicated no significant differences for RPE (p = 0.486), CMJ vertical height (VH; p = 0.344) and Tsk (p > 0.05) in any of the regions of interest after protocols. Significant differences (p < 0.05) were found for the time of data collection on Tsk with similar pre- and post-15 min values. In conclusion, Tsk decreased after both isometric and auxotonic effort at 70% of the maximal performance and recovered baseline values within 15 min of completion. Both efforts produced similar effects on skin temperature and did not affect jumping performance after exercise.


Subject(s)
Isometric Contraction , Thermography , Adolescent , Adult , Exercise , Humans , Lower Extremity , Muscle, Skeletal , Young Adult
14.
PLoS One ; 17(1): e0262276, 2022.
Article in English | MEDLINE | ID: mdl-35045106

ABSTRACT

Technical elements are related to shooting performance; however, the importance of each factor regarding performance, especially in elite-level pistol shooters, remains controversial. The objective of this study was to determine the technical factors that influence pistol performance. One elite-level shooter was analysed during the season before the Olympic classification European championship through a total of six competitions (n = 360 shots). Aiming point trajectories were measured with the SCATT optoelectronic system. Variables were classified into six categories: performance; aiming time; stability of hold; aiming accuracy; cleanness of triggering and shooting delta. Principal component analysis, multiple regressions, Pearson correlations and ANOVAs were used to analyse the data. The results showed that five components (aiming time, stability of hold, aiming accuracy, cleanness of triggering and shooting delta) determined a total of 79.68% of the shooting variance. Specifically, aiming accuracy and cleanness of triggering explained up to 25% of the shooting score, with cleanness of triggering serving as the determining factor. Correlations were found among the performance and stability of hold, aiming accuracy, cleanness of triggering and shooting delta. Last, significant differences were found among 8-score, 9-score and 10-score shots. We conclude that while aiming accuracy seems to be related to the performance, cleanness of triggering could be the most critical technical element; furthermore, while stability of hold does not seem to be a determining factor of the score, it could be a general prerequisite to achieve high levels of performance in elite-level air pistol shooters.


Subject(s)
Athletic Performance/physiology , Postural Balance/physiology , Psychomotor Performance/physiology , Adult , Firearms , Humans , Male , Principal Component Analysis , Task Performance and Analysis
15.
J Hum Kinet ; 80: 223-237, 2021 Oct.
Article in English | MEDLINE | ID: mdl-34868431

ABSTRACT

The relative age effect (RAE) is a phenomenon present in team sports, but it does not influence each gender to the same extent. This study aimed to examine the RAE and its relation to performance in international women's handball competitions (2017/18 World Championships). The sample was composed of 1,096 female players distributed into three categories: youth or under 18 (n = 369); junior or under 20 (n = 328) and senior (n = 399). The teams were divided into four groups based on their final position (medalist, quarter-finalist, eight-finalist and bottom-eight teams). The birthdate distribution (trimesters and semesters) was analysed according to the competition category and the playing position. Differences between the expected and observed birthdate distribution were checked using the chi-square statistical test followed by the calculation of the odds ratio. The results revealed, by trimester, the presence of the RAE in the youth (x2(7) = 87.22; p < 0.001) and junior (x2 (7) = 33.12; p < 0.001) categories, with no impact on senior (p > 0.05). The effect size was relatively strong in the youth category (Vc = 0.48). By semester, the prevalence of the RAE was also found in the senior category (p < 0.05). According to the playing position, the RAE was especially detected in 'goalkeeper' (p < 0.01) and 'centre-back' (p < 0.05) positions, both in U-18 and U-20 categories. Surprisingly, this effect also appeared in the 'back' players in the senior category (p < 0.05). A prevalence of the RAE was identified in teams with a higher final position, but interestingly had a greater impact in the quarter-finalist teams (p < 0.001) than in the medalist teams (p < 0.01). The findings demonstrated that the RAE tends to decrease as the chronological age of players increases, demonstrating a strong presence according to collective performance in international women's handball.

16.
Article in English | MEDLINE | ID: mdl-34682307

ABSTRACT

This systematic review aimed to examine the prevalence of the relative age effect (RAE) in swimming and its impact on competition performance according to different types of interacting constraints. A systematic literature search, following the PRISMA guidelines for preparing systematic reviews, was performed through four electronic databases, and nine studies met the inclusion criteria. The quality of the selected studies was evaluated using STROBE, and an average score of 16.2 points was obtained. In these studies, the prevalence of the RAE in swimming was observed in more than half (58.65%) of the participants analysed, and the effect of the RAE was more accentuated in young categories (decreased as age increased and was inverted in older ones) and in male swimmers (double that in female swimmers).The impact of the RAE on competitive performance appeared to be related to the strength demands of the event, as the performance in simultaneous strokes, in shorter events, and of swimmers in the postadolescence period seems to be more affected by the RAE. These results indicate that the RAE in competitive swimming relies on individual and environmental (the swimmer's age group and gender) but also task (the competitive events) determinants or limitations. This should serve as a guide for a more effective design of selection and development procedures for young athletes.


Subject(s)
Athletic Performance , Swimming , Aged , Athletes , Competitive Behavior , Female , Humans , Male , Prevalence
17.
Article in English | MEDLINE | ID: mdl-34501619

ABSTRACT

The outbreak of the COVID-19 pandemic and the resulting restrictions designed to slow the spread of infection greatly disrupted people's lives. The present study aimed to investigate the impact of lockdown on the psychology, training, and sleep habits of a cohort of basketball players. An online survey involving 169 professional and amateur athletes was conducted using four validated psychological questionnaires (WLEIS-S, POMS, BRS, SMS-II) and a Likert scale to measure the rating of perceived exertion (RPE) and training variables. Gender differences in fatigue (p = 0.022); friendships (p = 0.017); others' emotional appraisal (p < 0.001); and resilience (p = 0.031) were apparent, with higher values for women in all categories bar resilience. Comparisons before and during the lockdown revealed that all participants reduced their RPE (p < 0.001); training days (p = 0.004); and training hours (p < 0.001), and experienced a decline in the quality of sleep (p < 0.001). Sleep hours (p < 0.001) increased during lockdown. The professionals and females maintained their training days (p > 0.05), while the non-professionals and males did not. Psychological states during lockdown were a predictor of the differences in training and recovery variables. In situations where training and competition are limited, it is important to develop plans to maintain physical activity, good quality sleep, and promote greater emotional management and understanding to control negative moods.


Subject(s)
Basketball , COVID-19 , Athletes , Communicable Disease Control , Female , Habits , Humans , Male , Pandemics , SARS-CoV-2
18.
Plants (Basel) ; 10(8)2021 Jul 23.
Article in English | MEDLINE | ID: mdl-34451558

ABSTRACT

The cell wall (CW) is a dynamic structure extensively remodeled during plant growth and under stress conditions, however little is known about its roles during the immune system priming, especially in crops. In order to shed light on such a process, we used the Phaseolus vulgaris-Pseudomonas syringae (Pph) pathosystem and the immune priming capacity of 2,6-dichloroisonicotinic acid (INA). In the first instance we confirmed that INA-pretreated plants were more resistant to Pph, which was in line with the enhanced production of H2O2 of the primed plants after elicitation with the peptide flg22. Thereafter, CWs from plants subjected to the different treatments (non- or Pph-inoculated on non- or INA-pretreated plants) were isolated to study their composition and properties. As a result, the Pph inoculation modified the bean CW to some extent, mostly the pectic component, but the CW was as vulnerable to enzymatic hydrolysis as in the case of non-inoculated plants. By contrast, the INA priming triggered a pronounced CW remodeling, both on the cellulosic and non-cellulosic polysaccharides, and CW proteins, which resulted in a CW that was more resistant to enzymatic hydrolysis. In conclusion, the increased bean resistance against Pph produced by INA priming can be explained, at least partially, by a drastic CW remodeling.

19.
Sports (Basel) ; 9(7)2021 Jul 12.
Article in English | MEDLINE | ID: mdl-34357935

ABSTRACT

Relative age effects (RAEs) appear consistently prevalent throughout the youth basketball literature. However, the selection into and successful transition out of a national talent pathway in basketball is yet to be explored. Thus, the primary aim of this study was to explore the influence of relative age, gender, and playing time based on the selection into the Regional Talent Hubs and Basketball England youth teams (U16, U18, and U20) and the successful transition into the England National Senior Teams. Participants who were selected into the male (n = 450) and female (n = 314) Basketball England Talent Pathway were allocated into one of three cohorts: (a) Regional Talent Hubs (U12 to U15; n = 183), (b) England National Youth Teams (U16, U18, and U20; n = 537), and (c) England National Senior Teams (n = 44). A chi-square test was used to compare the birth quarter (BQ) distributions of each cohort against the expected distributions, with a Cramer's V (Vc) used to interpret effect sizes. Odds ratios (OR) and 95% confidence intervals were also calculated to compare the likelihood of each BQ being represented. Males revealed significant RAEs across both the Regional Talent Hubs (p < 0.001, Vc > 0.29, OR = 10) and England National Youth Teams (p < 0.001, Vc > 0.17, OR = 3.1). In comparison, females only had significant RAEs in the Regional Talent Hubs (p < 0.001, Vc > 0.29, OR = 2.3). Despite RAEs being prevalent throughout youth levels, there were no significant differences in the BQ distribution based on playing time and those who made the successful transition to the England National Senior Teams. These findings demonstrate the potential mechanisms of RAEs in basketball, as well as the impetus to explore more equitable competition structures within the England Basketball Talent Pathway.

20.
Front Psychol ; 12: 673434, 2021.
Article in English | MEDLINE | ID: mdl-34267706

ABSTRACT

Background: Competitive success is the ultimate objective of elite professional sport organisations. Relative age effects (RAE) impact athlete selection processes in the short and long-term performance. The aims of this study were: (i) examine the presence of RAE by gender, competitive level, and playing position, as well as evaluate the impact of RAE on individual (goals, percentage of effectiveness in shots, saves; percentage of effectiveness in saves, assists, turnovers, steals, blocked shots, penalties, minutes played, and minutes played per match) and collective competition performance (final team position); and (ii) analyse the impact of RAE on the evolutionary trends of individual performance in international competitions throughout 16 seasons in Spanish handball (2005-2020). Methods: The sample included 631 Spanish handball players (male: n = 359; female: n = 272). A Chi-square goodness-of-fit test was used to assess whether a skewed birthdate distribution occurred. A one-way analysis of variance (ANOVA) of independent measures was used to examine the individual and collective statistical parameters by birth quartiles. A linear regression in a Hopkins sheet were performed to compare individual performance trends. Results: The results revealed RAE in the male formative categories (p < 0.001), as well as the male and female senior categories (p < 0.05). By position, RAE especially affected the "centre-back" in the male formative (p < 0.01) and senior categories (p < 0.05). No significant relationship between RAE and individual performance was found in male formative categories, while an impact of RAE on the "minutes played" was detected in the female senior category (p < 0.05). With regard to collective performance, a higher number of relatively older handball players was observed in the best ranked teams in the male formative categories and in the quarter-final teams in the female formative categories (p < 0.05). Among the male players, relatively older players spent more minutes on the court than relatively younger players, although this advantage dissipated over time and did not lead to better performance. Among the female players, relatively younger players were found to perform better as the level of competitive handball increased. Discussion: These findings are important for talent identification and development policies in sport federations and other elite sport institutions by demonstrating the many unintended consequences of selections to international competitions at the youth level.

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