1,720,978 research outputs found

    Weight cycling in combat sports: revisiting 25 years of scientific evidence

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    Background: As combat sports are classified by body mass, many athletes engage in rapid weight loss (RWL) prior to competition so they can gain an advantage over lighter opponents. Following the weigh-in, athletes engage in rapid weight gain (RWG), whereby some athletes have been able to compete up to three weight categories greater than the official division weighed in at. Results: Although the impact of weight cycling on performance remains equivocal, robust scientific evidence indicates serious acute and chronic negative consequences on physiological and health-related parameters. Still, weight cycling remains highly prevalent in combat sports, and interventions to limit or stop this cultural norm are recommended. Conclusions: Weigh-ins for combat sports should be transitioned to take place closer to the start of competition. This reduced time and access to engage in RWG will cut down, if not completely prevent, weight cycling. These rule changes that aim to benefit athlete’s health and promote fairness must be made at the international level, which will promote them at those levels below, as well, given qualification protocols

    Lower back pain in young climbers: a retrospective cross-sectional study

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    ObjectiveThe popularity of sport climbing has been growing since its inclusion in the Olympic Games program, which led to more people practicing it on recreational, amateur, and professional levels. Strenuous climbing training sessions and competitions might lead to frequent and serious musculoskeletal injuries and complaints among competitive climbers. This study aimed to investigate the prevalence of low back pain (LBP) and to explore the influence of various risk factors on LBP in adolescent climbers.MethodsThe sample included 180 competitive climbers (46.6% males) aged 13-19 years competing in under-16 (48.3%) or under-20 categories. Data collection was carried out using the Nordic Musculoskeletal Questionnaire (NMQ) and the Graded Chronic Pain Scale (GCPS).ResultsA total of 74.4% of the entire sample of participants (male = 75%; female = 74%) reported lower back complaints throughout the past twelve months, and only 15.5% during the last seven days. A major part of complaints was classified as low intensity-low disability (Grade I, 62.8%; male = 72.6%; female = 54.2%). Under-20 competitors reported a small but significantly higher percentage of almost all NMQ measures compared to under-16 athletes.ConclusionsThis study found a relatively high prevalence of LBP, although complaints were of limited severity and did not affect climbers' regular training practice. Moreover, climbers did not differ in LBP prevalence according to sex, while climbers from the older age group reported higher complaints and seeking medical attention than younger climbers. Future studies should prospectively monitor the influence of climbing on LBP in youth climbers

    Make Fitness Fun: Could Novelty Be the Key Determinant for Physical Activity Adherence?

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    The benefits of physical activity (PA) are well known and are extensively delineated in the scientific literature. Regular participation in PA, or exercise as its subset (structured, preplanned form of PA), is positively associated with numerous physical and psychological health benefits across all population subgroups (i.e., different age groups, gender, ethnicity, and socioeconomic status) (Paterson and Warburton, 2010; Warburton and Bredin, 2017). The current PA guidelines for adults, proposed by the American College for Sports Medicine and American Heart Association (ACSM/AHA), recommend the accumulation of at least 150 min of moderate intensity aerobic PA per week (Nelson et al., 2007). Additionally, it is recommended that adults should engage in muscle-strengthening activities at least two times per week (Garber et al., 2011). Despite this, sedentary behavior remains a major challenge, and insufficient PA rates have remained stable at the global level between 2001 and 2016 (Guthold et al., 2018). Physical inactivity is the fourth leading cause of death worldwide and its annual health-care costs have been estimated at 53.8 billion US dollars in 2012 internationally (Ding et al., 2016). However, it has recently been shown that with sufficient PA, as many as 3.9 million premature deaths could be averted annually (Strain et al., 2020), and thus more needs to be done to improve engagement and maintenance of PA throughout the lifespan

    Cardiac response to Nage no Kata in judo

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    The first world judo Kata competition was held in October 2007 in Tokyo, Japan. The Nage no Kata was developed in 1884 and 1885 at the Kodokan. by Jigoro Kano, the founder of judo, who developed Kata to demonstrate the principles of judo and to provide a type of training which emphasized performing techniques under controlled setting. According to Kano, to fully develop judo skills, it is essential to involve both Randori and Kata techniques [1]. Most highgrade Japanese judo teachers emphasize the importance of Kata performance for judokas’ development, in particular Nage no Kata [2]. Results of the study conducted by Canestri et al. [3] suggested that session-RPE and HR monitoring is a simple and practical tool to quantify training loads in judo in different conditions. To date, no studies have investigated on possible association between HR and RPE related to Nage no Kata in judo athletes. Also, empirical evidence shows no studies that have researched correlation between Tori and Uke in any segment of judo performance. Thus, the aim of this study was to analyse the changes in HR and RPE of male and female judo athletes who performed Nage no Kata in a competitive setting

    Objectively evaluated physical activity among individuals following anterior cruciate ligament reconstruction: a systematic review and meta-analysis

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    Objective To compare time spent in moderate-to-vigorous physical activity (MVPA) per week, MVPA per day, and steps per day between individuals that were subjected to the anterior cruciate ligament reconstruction (ACLR) and healthy control group. Design Systematic review and meta-analysis of observational studies. Data sources Web of Science, Scopus, and PubMed have been comprehensively searched to identify relevant investigations. Eligibility criteria for selecting studies An observational research that objectively evaluated physical activity among respondents with a history of ACLR. Results Of 302 records, a total of 12 studies fulfilled the eligibility criteria. Four hundred and forty-three participants underwent the ACLR, 153 men and 290 women. The mean time between anterior cruciate ligament (ACL) surgery and evaluation of analysed outcomes was 34.8 months. The main findings demonstrated that the ACLR group spent less time in weekly MVPA (standardised mean differences (SMD)=−0.43 (95% CI −0.66 to −0.20); mean = −55.86 min (95% CI −86.45 to −25.27); p=0.0003; τ2=0.00), in daily MVPA (SMD=−0.51 95% CI −0.76 to −0.26]; mean = −15.59 min (95% CI −22.93 to −8.25); p<0.0001; τ2=0.00), and they had fewer daily steps (SMD=−0.60 95% CI −0.90 to −0.30); mean = −1724.39 steps (95% CI −2552.27 to −896.50); p<0.0001; τ2=0.00) relative to their non-injured counterparts. Additionally, available investigations indicated that individuals with a history of ACLR participated in 316.8 min of MVPA per week, 67 min in MVPA per day, and 8337 steps per day. Conclusion Long-term after ACLR, participants undergoing ACL surgery were less physically active compared with their non-injured peers, and they did not satisfy recommendations regarding steps per day. PROSPERO registration number CRD42023431991

    Going Beyond Counting First Authors in Author Co-citation Analysis

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    The present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed

    Variations on the Author

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    “Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship

    Appropriate Similarity Measures for Author Cocitation Analysis

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    We provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis

    The effects of rapid weight loss on skeletal muscle in judo athletes

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    Objective: To observe the effect of rapid weight loss (RWL) methods over 3 days on muscle damage in judokas. Methods: Eighteen judokas participated in this crossover study, meaning that judo athletes were subjected to exercise-only phase (4 days) and RWL phase (3 days). Subjects were tested for myoglobin, creatine kinase, aldolase, hemoglobin, and hematocrit values on seven consecutive days. These biomarkers served as indicators of acute muscle damage. Results: During the exercise-only phase, no significant changes were observed. Myoglobin (Mb) (p < 0.001), creatine kinase (CK) (p < 0.001) and aldolase (ALD) (p < 0.001) significantly increased only during the RWL phase, as well as hemoglobin (Hb) (p < 0.001) and hematocrit (Hct) (p < 0.005) values. It was detected that peak values for muscle damage biomarkers were reached on the sixth day, while Hct and Hb values were the highest on the seventh day of the study. Conclusion: Our study showed significant muscle damage induced by RWL. The prevalence of RWL use by judokas is high but firm scientific evidence is lacking in the evaluation of the current practice of it. Therefore, further knowledge must be gained to evaluate the effectiveness of RWL on performance and its impact on judokas' wellbeing
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