http://hdl.handle.net/10256/16303 Thu, 19 Jun 2025 10:43:10 GMT 2025-06-19T10:43:10Z http://hdl.handle.net/10256/26149 Explosive strength, arm-swing jump contribution and eccentric utilization ratio in youth and junior female volleyball players Vasileva, Fidanka; Misovski, Andrijana; Milenkoski, Josko; Georgiev, Georgi; Aceski, Aleksandar; Vasilev, Angjel Vertical jumps are a defying predictor of performance in sports that require explosive action. Objectives of the present study are: 1) to evaluate anthropometric characteristics (height, body mass and BMI), explosive strength (squat jump, countermovement jump and countermovement jump with an arm-swing) and kinematic parameters (the arm swing jump contribution and the eccentric utilization ratio) in female volleyball players; and 2) to compare assessed parameters between youth and junior players. Thirty participants, players that are part of Macedonian Youth (N=15) and Junior (N=15) National Teams, aged 13-18 years, were included in the study. Anthropometric characteristics were measured according to the WorldHealth Organization manual, explosive strength was assessed with the Optojump system, and kinematic parameters were calculated as proposed by Abdel-Rahman (2013). SPSS 23 statistical package was used to perform statistical analysis. Normality of data distribution was tested by K-S test, Skewness and Kurtosis values. Appropriate statistical methods were used to calculate descriptive statistical parameters, and t-test was applied to determine the significance of the difference between youth and junior players. In addition, Cohen's d was applied to calculate the effect size. No statistically significant differences were found between youth and junior players in parameters assessed. Coaches should take in consideration anthropometric and morphological characteristics of the players during the selection process, and work more in a direction of motor abilities development and improvement of technical skills, especially in pioneer and youth categories, instead of putting the main emphasis on player specialization at early age Wed, 15 Jun 2022 00:00:00 GMT http://hdl.handle.net/10256/26149 2022-06-15T00:00:00Z http://hdl.handle.net/10256/25516 The Knowledge Map of Sport and Exercise Psychology: An Integrative Perspective Latinjak, Alexander T.; Hatzigeorgiadis, Antonis The present work contains a personal perspective on what sport and exercise psychology (SEP) is today. It is a global synthesis of research about psychological aspects related to the context and practice of sport and exercise. The intended impact was to positively influence teaching SEP to students, to promote interdisciplinary research and practice, and to assist the development of SEP as an applied science by helping experts develop a more holistic view of the field. Over 650 theoretical and review articles about psychological concepts in connection to sport and exercise were read in the process of creating a conceptual model that reflects the essence of SEP and leads to a conceptualization of SEP based on research topics. The result was a knowledge map of SEP made up of four main research clusters: biopsychological descriptors, external variables, psychological skills, and applied SEP practice. In terms of interdisciplinarity, the present perspective on SEP suggests that sport and exercise can be used as a research paradigm or natural laboratory to study psychological aspects relevant to various scientific fields, and that sport and exercise can be used as a therapeutic framework in response to challenges that researchers and practitioners in these fields are typically addressing Wed, 16 Jun 2021 00:00:00 GMT http://hdl.handle.net/10256/25516 2021-06-16T00:00:00Z http://hdl.handle.net/10256/25514 Cardiorespiratory Coordination During Exercise in Adults With Down Syndrome Oviedo, Guillermo R.; Garcia Retortillo, Sergi; Carbó Carreté, Maria; Guerra-Balic, Myriam; Balagué, Natàlia; Javierre, Casimiro; Guàrdia Olmos, Joan Down syndrome (DS) is a chromosomal disorder affecting simultaneously cardiovascular and respiratory systems. There is no research studying the coupling between these systems during cardiorespiratory exercise testing in a population with DS. Cardiorespiratory coordination (CRC), evaluated through principal component analysis (PCA), measures the covariation of cardiorespiratory variables during exercise. Objective: To investigate and compare CRC in adults with and without DS during maximal cardiorespiratory exercise testing. Methods: Fifteen adults with DS and 15 adults without disabilities performed a maximal cardiorespiratory exercise test on a treadmill. First, the slope, and afterward the velocity was increased regularly until participants reached exhaustion. The time series of six selected cardiorespiratory variables [ventilation per minute, an expired fraction of O2, the expired fraction of CO2, heart rate, systolic blood pressure (SBP), and diastolic blood pressure (DBP)] were extracted for the analysis. The number of principal components (PCs), the first PC eigenvalues (PC1), and the information entropy were computed for each group (non-DS and DS) and compared using a t-test or a Mann-Whitney U test. Results: Two PCs in the non-DS group and three PCs in the DS group captured the variance of the studied cardiorespiratory variables. The formation of an additional PC in the DS group was the result of the shift of SBP and DBP from the PC1 cluster of variables. Eigenvalues of PC1 were higher in the non-DS (U = 30; p = 0.02; d = 1.47) than in the DS group, and the entropy measure was higher in the DS compared with the non-DS group (U = 37.5; p = 0.008; d = 0.70). Conclusion: Adults with Down syndrome showed higher CRC dimensionality and a higher entropy measure than participants without disabilities. Both findings point toward a lower efficiency of the cardiorespiratory function during exercise in participants with DS. CRC appears as an alternative measure to investigate the cardiorespiratory function and its response to exercise in the DS population Wed, 08 Sep 2021 00:00:00 GMT http://hdl.handle.net/10256/25514 2021-09-08T00:00:00Z http://hdl.handle.net/10256/25513 Cardiorespiratory Coordination in Repeated Maximal Exercise Garcia Retortillo, Sergi; Javierre, Casimiro; Hristovski, Robert; Ventura, Josep Lluis; Balagué, Natàlia Increases in cardiorespiratory coordination (CRC) after training with no differences in performance and physiological variables have recently been reported using a principal component analysis approach. However, no research has yet evaluated the short-term effects of exercise on CRC. The aim of this study was to delineate the behavior of CRC under different physiological initial conditions produced by repeated maximal exercises. Fifteen participants performed 2 consecutive graded and maximal cycling tests. Test 1 was performed without any previous exercise, and Test 2 6 min after Test 1. Both tests started at 0 W and the workload was increased by 25 W/min in males and 20 W/min in females, until they were not able to maintain the prescribed cycling frequency of 70 rpm for more than 5 consecutive seconds. A principal component (PC) analysis of selected cardiovascular and cardiorespiratory variables (expired fraction of O2, expired fraction of CO2, ventilation, systolic blood pressure, diastolic blood pressure, and heart rate) was performed to evaluate the CRC defined by the number of PCs in both tests. In order to quantify the degree of coordination, the information entropy was calculated and the eigenvalues of the first PC (PC1) were compared between tests. Although no significant differences were found between the tests with respect to the performed maximal workload (Wmax), maximal oxygen consumption (VO2 max), or ventilatory threshold (VT), an increase in the number of PCs and/or a decrease of eigenvalues of PC1 (t = 2.95; p = 0.01; d = 1.08) was found in Test 2 compared to Test 1. Moreover, entropy was significantly higher (Z = 2.33; p = 0.02; d = 1.43) in the last test. In conclusion, despite the fact that no significant differences were observed in the conventionally explored maximal performance and physiological variables (Wmax, VO2 max, and VT) between tests, a reduction of CRC was observed in Test 2. These results emphasize the interest of CRC evaluation in the assessment and interpretation of cardiorespiratory exercise testing Wed, 07 Jun 2017 00:00:00 GMT http://hdl.handle.net/10256/25513 2017-06-07T00:00:00Z