70 research outputs found
Utjecaj datuma rođenja na vrijeme provedeno u igri tijekom međunarodnih rukometnih natjecanja s obzirom na igračku poziciju
While a relative age effect (RAE) has been reported in handball, such analyses do not consider the actual playing time during competitions, which may actually have more impact on matches performance in matches. The objective of the present study was to examine the RAE on playing time during international competitions with respect to playing positions. Team compositions (477 players) of the quarter finalists of the 2012 Olympic Games, 2013 World Championships, and 2014 European Championship were analyzed. Month and year of birth where collected in the starting list of each team for center, left and right backs, left and right wings, goalkeepers and pivots. Players were categorized into birth quartile (Q1 Jan–Mar; Q2 Apr–Jun; Q3 Jul–Sep; and Q4 Oct–Dec) and as odd/even year. Playing times were retrieved from official statistics. Data were analyzed for practical significance using magnitude-based inferences. We observed a strong selection bias towards players born earlier within a two-year selection period for all playing positions (Chi-square, p<.001). There was, however, an inconsistent effect of age (i.e. expected, reversed or a lack of) on actual playing time during competitions. In conclusion, the present study showed for the first time that, despite its large effect on players’ selection, players’ relative age had a limited and position-dependent effect on their actual playing time during top-level competitions. Present findings suggest that the reasons supporting the relative age effect with respect to team selection are at odds with the current utilization of players by coaches in the field.Iako je utjecaj relativne dobi igrača potvrđen u rukometu, takve analize ne uzimaju u obzir stvarno vrijeme provedeno u igri tijekom natjecanja, a što može snažnije utjecati na uspješnost tijekom utakmice. Cilj je ovog istraživanja bio utvrditi utjecaj relativne dobi igrača na vrijeme igranja tijekom međunarodnih natjecanja s obzirom na igračku poziciju. Analizirane su postave nacionalnih selekcija (477 igrača) koje su igrale četvrtinu finala na Olimpijskim igrama 2012. godine, Svjetskom prvenstvu 2013. te Europskom prvenstvu 2014. godine. Informacije o mjesecu i godini rođenja za srednje, lijeve i desne vanjske igrače, lijeva i desna krila, vratare i kružne napadače prikupljeni su iz službenih startnih popisa svake momčadi. Igrači su podijeljeni u kvartile definirane prema datumu rođenja (Q1 – siječanj do ožujak, Q2 – travanj do lipanj, Q3 – srpanj do rujan i Q4 – listopad do prosinac) te prema tomu jesu li rođeni u parnoj ili neparnoj godini. Vrijeme provedeno u igri za svakog igrača dobiveno je iz službenih statistika. Veličina učinka analizirana je u odnosu na minimalnu značajnu praktičnu vrijednost. Uočili smo snažnu selekcijsku pristranost prema igračima koji su rođeni ranije unutar dvogodišnjeg selekcijskog perioda za sve igračke pozicije (χ2, p<0,001). Ipak, utvrđen je i nekonzistentan utjecaj dobi (tj. očekivan, suprotan ili izostanak utjecaja) na stvarno vrijeme igranja tijekom natjecanja. Zaključno, ovo je istraživanje prvi put pokazalo da, usprkos velikom utjecaju na selekciju igrača, relativna dob igrača ima ograničen te o pozicijama ovisan utjecaj na stvarno vrijeme igranja igrača tijekom velikih natjecanja. Rezultati pokazuju da su razlozi za podržavanje utjecaja relativne dobi igrača u kontekstu selekcije igrača u ekipu u suprotnosti s trenerovim stvarnim korištenjem igrača
Respiratory muscle strength is decreased after maximal incremental exercise in trained runners and cyclists
The respiratory muscle fatigue seems to be able to limit exercise performance and may influence the determination of maximal oxygen uptake (VO2max) or maximum aerobic work rate during maximal incremental test. The aim of this study was therefore to investigate whether maximal incremental exercise decreases respiratory muscle strength. We hypothesized that respiratory muscle strength (maximal pressure) will decrease after maximal incremental exercise to exhaustion. 36 runners and 23 cyclists completed a maximal incremental test on a treadmill or a cycle ergometer with continuous monitoring of expired gases. Maximal inspiratory (MIP) and expiratory (MEP) pressure measurements were taken at rest and post- exercise. At rest, the MIP and MEP were 140 +/- 25 and 172 +/- 27 in runners vs. 115 +/- 26 and 146 +/- 33 in cyclists (p 0.05), respectively. Our results suggest that respiratory muscle strength is decreased following maximal incremental exercise in trained runners and cyclists
Physiological responses to shuttle repeated-sprint running
This study investigated the influence of 180° changes of direction during a repeated-sprint running test on performance, cardiorespiratory variables, muscle deoxygenation and post-exercise blood lactate ([La]b) levels. Thirteen team-sport athletes (22±3 yr) performed 6 repeated maximal sprints with (RSS, 6×[2×12.5 m]) or without (RS, 6×25 m) changes of direction. Best and mean running time, percentage speed decrement (%Dec), pulmonary oxygen uptake (V˙ O2), vastus lateralis deoxygenation (Hbdiff) and [La]b were calculated for each condition. Best and mean times for both protocols were largely correlated (r=0.63 and r=0.78, respectively), and were ‘almost certainly’ higher for RSS compared with RS (e. g., 5.30±0.17 vs. 4.09±0.17 s for mean time, with the qualitative analysis revealing a 100% chance of RSS time being greater than RS). In contrast, %Dec was‘possibly’ lower for RSS (2.6±1.2 vs. 3.2±1.3%, with a 79% chance of a real difference). Compared with RS,V˙ O2 (40.4±4.2 vs. 38.9±3.8 mL.min−1.kg−1, with a 90% chance of a real difference) and [La]b (10.0±1.7 vs. 9.3±2.4 mmol.L−1, with a 70% chance of a real difference) were‘possibly’ higher. Conversely, there were no differences in Hbdiff (11.5±3.2 vs. 10.9±3.0 μM, with the comparison rated as‘unclear’). To conclude, the present results suggest that the ability to repeat sprints can be considered as a general quality. They also suggest that repeated shuttle sprints might be an effective training practice for eliciting a greater systemic physiological load, but perhaps not a greater loading of the vastus lateralis
Is there a beneficial effect difference between age, gender, and different cardiac pathology groups of exercise training at ventilatory threshold in cardiac patients?
Background: Research on cardiac rehabilitation has raised interesting methods and effects
without however establishing the share of the profits according to age, sex and cardiac pathology.
Yet today, this disease with various pathologies strikes people of all ages and both sexes, and
the recommended rehabilitation exercise intensity is often the ventilatory threshold. The aim of
this study was to compare benefits of a training program at ventilatory threshold according to
age, gender and cardiac pathology.
Methods: One hundred and eighty eight cardiac patients, of whom 62 had coronary artery
bypass surgery, 22 artery angioplasty, 54 myocardial infarction and 50 valve replacements,
aged 31–82 years, performed spirometric and cardiopulmonary exercise tests before and after
a training program. This program consisted of exercise on a cycloergometer for three sessions
of 45 min per week for eight weeks at heart rates attenuated at ventilatory threshold (VTh)
obtained during a cardiopulmonary exercise test conducted before the training period.
Results: Peak heart rate, peak aerobic power, and peak oxygen uptake determined at VTh
increased during the training period in all groups of subjects. Men and adult groups had
higher absolute values compared to women and elderly groups. No difference was observed in
cardiac pathology groups. Similar improvements of aerobic capacities were observed in age,
gender and cardiac pathology groups.
Conclusions: A training program conducted at personalised VTh significantly improves the
aerobic physical capacities of all cardiac patients, and inducessimilar benefits whatever the
age, gender or cardiac pathology. (Cardiol J 2011; 18, 6: 632–638
The Livelihood Change of Fishermen Recipient Grant Program of Coalition Party in Lubuk Puding Village Buru District of Karimun Regency of Riau Islands Province
This study was conducted in January 2016 in the village of Lubuk Puding in the District of Buru Karimun Riau Islands Province. The objective of this study was to determine the characteristics of fishing grantees, to determine changes in fishing livelihoods after receiving the grant, and to determine the relationship characteristic of changes, livelihoods and grants program. The method used in this study was survey of 160 grantees fishermen population, in which this study taken as much as 15% of the 160 populations or 24 peoples.Based on the research result, the characteristics of grant recipient are productive fishermenage, low education and the number of family member of fishermen. The livelihood of fishermen grant recipients changed from the preparatory stage to the growth stage, while in food consumption and employment on a fixed income and sanitation and hygiene unchanged. Characteristics with real changes in the livelihoods of fishermen are age which have relationship with income and with the job opportunities, the number of family member has relationship with food consumption and grant, and food consumption have relationships with the grant
FIFA World Cup Qatar 2022: Solutions to the Physical Fitness Challenge
In 2022, the FIFA World Cup has been scheduled to take place in Qatar in November and December, months which coincide with the in-season period of the European soccer season. This will be challenging for the staff of the participating national teams and the domestic clubs to which participating players are attached. The aim of this letter to the editor is to propose solutions on how to manage the associated challenges.
Regular training and competition over the course of a season in European professional soccer is generally characterized by a pre-competition preparation period of five to six weeks, followed by two competition phases, interspersed with a winter break (Eliakim et al., 2018). Certain leagues such as the English Premier League do not typically have a winter break meaning that games are played almost continuously across the season. During World Cup years, there is usually an average of four to five weeks between the end of national domestic championships and the start of the World Cup tournament (Table 1, Figure 1) which traditionally takes place during the off-season period.
However, in 2022, the FIFA World Cup has been scheduled to take place in November and December, months which coincide with the in-season period of the European soccer season (Figure 1). With the World Cup being staged during this part of the season, many national team players (notably those in the major European Leagues) will have just one week of preparation between the last match of their domestic leagues and the start of the World Cup tournament (November 20th, 2022). More precisely, the major European soccer leagues will interrupt match schedules between November 9th and 13th with differences in the number of games completed at this time of the season ranging from 14 to 17 across the various leagues (Table 2).
The physical and mental demands placed on modern professional players have steadily risen over recent years due to an increase in the number of matches played during congested periods across the season (Anderson et al., 2016). Since the number of matches is not evenly distributed across the typical 40-week season, players can often compete in as many as three matches in a seven-day period. Aside from the physical and mental demands that are imposed during a match, players might experience insufficient recovery between these games; in part due to extensive travelling which can disrupt the sleep/wake cycle (Lastella et al., 2019). Indeed, poor quality of sleep and the stress induced by a match can negatively affect physical fitness and may even increase the risk of sustaining injuries and/or infections (Clemente et al., 2021) in the period leading up to the World Cup.
National teams are composed of players from different leagues who have varying levels of exposure to match-play (e.g., starters, non-starters) in terms of the average weekly volume of soccer matches at their clubs (“Rapports - Observatoire du football CIES”). Moreover, both starters and non-starters are exposed to different external match and training loads (Anderson et al., 2016). External loads have previously been defined as the overall volume of activity that a player performs during both training sessions and matches (Ravé et al., 2020). There is evidence that this metric correlates with a player’s physical fitness status (Clemente et al., 2019) and their injury risk (Malone et al., 2017). Accordingly, it will be challenging for national teams to manage the fitness of players such that they are physically ready to play at the World Cup tournament. This is especially applicable to individuals who play in the major European leagues and we note a significant contrast between European match schedules and those on other continents. For example, in Major League Soccer (MLS) in North America, match schedules will be interrupted from November 5th, 15 days before the World Cup tournament begins. Similarly, in the Japanese J-League in Asia, Saudi Pro League and Qatar Star League, matches will be interrupted one month before the World Cup tournament begins, leaving more time for players on these continents to prepare.
It is also important to note that the French, Spanish and English domestic championships will resume their match schedules on December 27th which is just ten days after the end of the World Cup (Figure 1). Clubs will clearly want their players to return uninjured and with sufficient fitness levels to resume domestic competition but these goals could be compromised by the aforementioned scheduling of the World Cup tournament.</jats:p
Changement de direction en course à pied (réponses physiologiques et effets sur la performance)
Dans de nombreux sports collectifs, la vitesse et les changements de direction (CDDs) sont considérés comme des paramètres déterminants de la performance. Ces CDDs peuvent se faire en demi-tour (180 ), ils sont alors définis comme des exercices en navette, ou de façon latérale à différentes vitesses et à différentes angulations. Or, cette habilité dépend de différents facteurs neuromusculaires et métaboliques. Le but de notre travail était donc 1)- d examiner des méthodes innovantes pour évaluer la capacité de CDD et le coût énergétique (Cr) avec CDD lors de tests incrémentaux 2)- d étudier l effet des CDDs sur la performance et les réponses physiologiques lors des exercices à différentes intensités de courses: sous-maximales (45, 60, 75, 90% de la vitesse maximale aérobie ; v 2max), maximales (tests incrémentaux) et supra-maximales (répétitions de sprint) et 3)- d analyser l effet de l angulation des CDDs (45,90, 135) sur la performance et les réponses physiologiques lors d exercices de répétition de sprints. 75 joueurs de sport collectifs sains, âgés de 18 à 30 ans ont participé aux études. L ensemble de ce travail de thèse a généralement permis de montrer que les changements de direction majorent les réponses physiologiques d un effort donné et affectent la performance. Les exercices de course sous-maximale (60, 75, 90% de v 2max) et maximale avec CDD sont associés à un coût énergétique plus élevé qui et une fatigabilité plus importante. Lors des exercices de course supra-maximale répétée, cette fatigabilité était en sus dépendante des angles des CDDs. L'estimation d une économie de course spécifique aux sports collectifs (incluant accélérations, décélérations et de CDD) semble être possible avec l'utilisation de plusieurs courses sous-maximales rectangulaires en navette, mais pas lors des tests incrémentaux sur piste avec des athlètes non spécialisés en endurance.AMIENS-BU Lettres (800212104) / SudocSudocFranceF
Evaluation des réponses et des adaptations cardiorespiratoires et neuromusculaires suite au réentraînement physique chez les patients coronariens (intérêt des tests de terrain, de l'entraînement aérobie et de la musculation)
AMIENS-BU Santé (800212102) / SudocSudocFranceF
Facteurs de variation de l'aptitude physique anaérobie (approche bioénergétique et électromyographique)
La présente thèse s'intéresse à l'évaluation des aptitudes physiques anaérobies par le moyen d'un test de terrain (la détente verticale) et, à la détermination des aspects bioénergétiques et neuromusculaires des exercices intenses répétés et brefs à charge croissante par le moyen d'un test de laboratoire (l'épreuve force-vitesse). Au total 15 sujets masculins sains et sportifs ont participé à l'épreuve force-vitesse. Ce test devrait servir, d'une part à comparer les aspects bioénergétiques et neuromusculaires des sujets Noirs et Blancs et, d'autre part à déterminer les effets d'une pré élévation par un exercice préalable intense de la lactatémie sur la puissance mécanique externe lors des exercices intenses répétés brefs à charge croissante. La comparaison de 9 sujets Noirs et 6 sujets Blancs appariés en aptitudes aérobies et en caractéristiques anthropométriques montrent qu'il existe des différences, mais très faibles entre les deux groupes de sujets au niveau des aspects bioénergétiques et neuromusculaires sur le plan anaérobie. Si la pré-élevation de la lactatémie chez 12 sujets par un exercice préalable intense n'a pas modifié significativement la puissance maximale anaérobie, elle a modifié de manière significative les comportements bioénergétiques et neuromusculaires lors de l'épreuve force-vitesse. L'étude transversale des aptitudes physiques anaérobie a connu la participation de 138 sujets divisés en 14 groupes en fonction de leurs sexes, âges (13,15, 17, 19 ans), ethnies (sujets Noirs et Bancs) et spécialités sportives (sprinters, demi-fondeurs et fondeurs). La détente verticale a consisté à réaliser un squat jump, un countermovement jump et un rebound jump sur l'ergojump. Les hauteurs de saut et les capacités des puissances anaérobies recueillies via le micro-ordinateur (psion) relié à l'ergo-jump ont permis de comparer les différents groupes de sujets. Les résultats de l'étude montrent que les plus âgés sautent plus haut et ont une capacité de la puissance anaérobie significativement plus importante que celle des plus petits. Les entraînés (surtout les sprinters) sont significativement plus performants que les non entraînés d'âge et de sexe identique. Cependant entre les filles et les garçons de même âge les garçons ont les performances supérieures mais sans différence significative. De même chez les sujets Noirs et Blancs, les différences sont très faibles et ne sont pas statiquement significatives.The present report interested the determination of the bioenergetics and electromyographics during repeated brief and intense exercises with increasing load friction using a laboratory test (force velocity test) and, the assement of the anaerobic fitness using vertical jump test. Fifteen healthy males subjects participated in the force-velocity test. This test permitted, on the one hand to compare the bioenergetics and neuromuscular aspects of the Black and White subjects and, on the other hand to determine the effects of a pre-elevation of blood lactate concentration by a previous intense exercise on the external mechanical power during the force-velocity test. The comparison of 9 Black subjects and 6 White subjects matched in aerobic aptitude and in anthropometrics characteristics showed that some differences existed, but very weak between the two groups of subjects in bioenergetics and neuromuscular aspects during the force-velocity test. If the pre-elevation of the blood lactate concentrations in 12 subjects by a previous intense exercise didn't modify the anaerobic maximal power, it modified the bioenergetics and neuromuscular aspects during the force-velocity test. A total of 138 subjects participated in the transverse survey of the anaerobic physical aptitude. They were separated in 14 groups according to their sexes, ages (13, 15, 17, 19 years), ethnic groups (Black subjects, and white subjects), and sports specialties (sprinters and long distance). The vertical jump consisted in achieving a squat jump, a countermovement jump and a rebound jump on the ergojump. The heights of jump and the anaerobic power were collected via a microcomputer (psion) connected on the ergo-jump. These variables permitted to compare different groups of subjects. The results showed significant increase of anaerobic power with the increase of âge. However between girls and boys with similar âge, boys demonstrated higher performance than girls but without significant difference. With identical âge and sex trained subjects are significantly more performing than untrained subjects. The differences between Black and White subjects are very weak and not statistically significant.AMIENS-BU Lettres (800212104) / SudocSudocFranceF
Contraintes ventilatoires à l'exercice chez l'obèse (effets de l'entraînement)
Les principales complications respiratoires de l obésité sont une demande accrue de ventilation, une augmentation du travail respiratoire, l inefficacité des muscles respiratoires et une diminution de la compliance respiratoire. Ces personnes présentent également une aggravation de la dyspnée et une diminution de la capacité d effort, éléments essentiels à la qualité de vie. Notre étude montre une que l exercice physique induit l installation de contraintes ventilatoires caractérisé par une augmentation du travail respiratoire, diminution de la force des muscles inspiratoires, altération de la performance des muscles inspiratoire, une dyspnée d effort et une distension pulmonaire dynamique à l exercice physique. Ces résultats sont donc en faveur de l existence d un cercle vicieux du déconditionnement chez ces sujets et ce d autant plus que leur activité physique était corrélé à leur tolérance à l effort. Ces observations justifient ainsi la prescription d un réentraînement pour améliorer la tolérance à l effort et la qualité de vie des sujets obèses. Nous avons montrés que le réentraînement à l effort améliore la tolérance à l effort, la performance des muscles inspiratoires et diminue la dyspnée d effort. En conclusion, les sujets obèses présentent des contraintes ventilatoires à l exercice constituant un facteur limitant à l exercice, le réentraînement à l effort chez les obèses constitue un traitement pertinent pour améliorer la tolérance à l effort et la qualité de vie des sujets obèses et permettre ainsi de freiner l évolution de la maladie vers l invalidité et le handicap psychosocialThe major respiratory complications of obesity include a heightened demand for ventilation, elevated work of breathing, respiratory muscle inefficiency and diminished respiratory compliance. Obese patients have increased dyspnoea and decreased exercise capacity, which are vital to quality of life. Our study shows that physical exercise is accompanied by an increased work of breathing, weakness of the inspiratory muscles, alteration of the inspiratory muscle performance, dyspnea of and a dynamic hyperinflation. Thus, these results are in favor of the existence of a vicious circle of deconditioning in these subjects and particularly as their physical activity were correlated with their exercise tolerance. These observations justify the prescription of endurance training to obese subjects to improve the exercise tolerance and the quality of life. Our results demonstrate that training improves exercise tolerance, performance of the inspiratory muscles and decrease dyspnoea. In conclusion, the obese subject present ventilatory constraints during exercise constituting a limitant factor to exercise, training improve exercise tolerance and the quality of life inducing a possible slow down to the evolution of the disease towards disability and psychosocial handicap in obese subjectsAMIENS-BU Lettres (800212104) / SudocSudocFranceF
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