Ερευνητικά

The importance of aerobic capacity and nutrition in recreational master mountain runners’ performance and race-induced changes in body composition and biochemical blood indices.

 

Spyridon Methenitis, Evgenia D. Cherouveim, Christos Kroupis ,Argyrios Tsantes, Kleopatra Ketselidi, Elpiniki Vlachopoulou,
George Stavroulakis, Andreas Mavrogenis, Charilaos Tsolakis and Panagiotis Koulouvaris

Abstract
This study aimed to explore the importance of aerobic capacity and nutrition on 28-km mountain running performance and race-induced changes in body composition and biochemical blood indices, in recreational master athletes of different performance levels. Twenty male master runners (age: 44.6 ±7.7 years) were divided into two groups, slower and faster runners, according to their race performance. Maximum oxygen uptake (VO2max), velocity at VO2max (vVO2max), oxygen consumption ( VO2Thr), and velocity (vVO2Thr) during the second ventilatory threshold were evaluated. Nutrition was assessed for one week before and during the race. Body composition was evaluated, and blood samples were collected before and 3 h after the race. Slower runners exhibited a greater reduction in lean body mass and greater changes in all muscle damage/inflammation/metabolism blood indices than the faster runners (η2=0.201–0.927; p < 0.05). When all the participants were assessed as one group (n=20), significant correlations were found between (vVO˙ 2max, vVO2Thr, race time, energy intake, expenditure, carbohydrate, protein intakes, and post-race changes in body composition and blood markers (r: −0.825–0.824; p < 0.05). The strongest determinants were (vVO˙ 2max and vVO2Thr, while energy intake, expenditure, carbohydrate, and protein intakes seemed to be the weakest determinants of race performance and race-induced changes in body composition and blood indices. The results suggest that race-induced changes in body composition and blood indices are determined mainly by master runners’ race performance and endurance capacity and to a lesser extent by nutrition. However, it seems that carbohydrate and protein intakes have equal importance.

 

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Bilateral asymmetries in male and female young elite fencers in relation to fencing performance

Vasiliki Drakoulaki, Nikolaos Kontochristopoulos, Spyridon Methenitis, Theocharis Simeonidis, Evgenia Cherouveima, Panagiotis Koulouvaris, Olga Savvidou and Charilaos Tsolakis

Abstract.
BACKGROUND: Data about lower extremities’ strength and power asymmetries in fencers, and their relationships to fencing performance are limited and inconsistent.
OBJECTIVE: The aim of the present study was to investigate asymmetries, between dominant (D) and non-dom (ND) legs of elite young male and female fencers, in relation to performance in fencing specific tests.
METHODS: Anthropometric characteristics, unilateral vertical-horizontal jumping, isokinetic strength, lunge and step lunge performances were evaluated in 16 male and 22 female elite fencers.
RESULTS: Significant differences between genders were found for all anthropometric measurements (p < 0.05). No significant bilateral asymmetries and gender x laterality effects were observed (p > 0.05). Fencing performance was negatively correlated with the D leg’s flexion/extension (F/E) ratio at 300◦ /s (r: −0.564 to −0.619, p < 0.05). In addition, D leg’s F/E ratio at 300◦ /s was positively related to lung peak velocity and power in female fencers (r: 0.562–0.649; p < 0.05). Finally, only in female fencers, unilateral triple hop distance was significantly related to lung peak velocity and power (r: 0.442–0.500; p < 0.05).
CONCLUSIONS: The results of the present study suggest that the differential activation/movement pattern of the D and ND leg muscles do not lead to anatomical, dynamic and functional lower extremities asymmetries.

 

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The science of biomechanics can promote dancers’ injury prevention strategies

 

Aspasia Fotaki , Athanasios Triantafyllou , Georgios Papagiannis , Sophia Stasi , Papathanasiou Georgios , Savvidou Olga , Charilaos K. Tsolakis & Panayiotis Koulouvaris

ABSTRACT
Background: The most common sports activities leading to menisci injuries are tennis, jogging, gymnastics, and dancing. Menisci injuries in dancers most frequently occur due to rotational forces applied to the knee. Objectives: Since dancers’ movement is of great biomechanical and rehabilitation interest, the purpose of this review is to explore the biomechanical approach of this issue as well as to identify any gap to this process and propose corresponding assessments. A literature review search database of Pubmed, Medline, EMBASE, AMED, Scopus, Google Scholar, and CINAHL was conducted using relevant keywords and phrases.
Major Findings: The most common dance movement that can cause meniscus injury, is the grand plie, because of the excessive range of motion combined to compressive forces and axial rotations that occur during the execution of the movement.
Conclusions: A complete three-dimensional kinematic assessment of the lower limb joints from dynamic grand plies or in intermidiate positions of the legs has not been made. Thus, further research has to be done with the use of optoelectronic cameras and force plates, to accurately identify weather excessive knee rotation range of motion or moments could lead in medial or/and lateral meniscus tear during the grand plie.

 

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Neuromuscular Screening to predict young fencers’ performance

 

Charilaos Tsolakis, Yiannis E. Tsekouras, Theodoros Daviotis, Panayiotis Koulouvaris, Panayiotis J. Papaggelopoulos

 

Abstract
The aim of this study was to investigate sport specific correlates of fencing performance, in both young male and female fencers. All assessments (anthropometry, arm strength, leg power, flexibility, fencing movement reaction times in visual stimuli velocity of arm extension, lunge velocity, step and lunge velocity and fencing specific agility test) were conducted on 9 males and 13 female young fencers 13.4±0.85 years old (mean age± standard deviation). Relationships were examined by calculating Pearson’s product moment correlation coefficient (r). A stepwise multiple linear regression was used to identify the best predictors of fencing performance. Females were found to have more body fat and higher BMI values compared to males. Males outperformed females in all leg power tests, while females were more flexible than males. Moreover males were faster in arm velocity, step-lunge velocity and change of direction velocity compared to females. Anthropometric parameters were not correlated to fencing performance. Long jump and squat jump were the best predictors of step and lunge velocity and change of direction velocity, respectively. The integration of power exercises in both the horizontal and vertical plane is recommended as regular regimen in physical condition protocols in order to optimize the fencing performance in young fencers.

 

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FORCE-VELOCITY RELATIONSHIP BETWEEN SPRINTING AND JUMPING TESTING PROCEDURES

Ioannis Stavridis, Angela Tsopanidou, Charilaos Tsolakis, Elias Zacharogiannis, Panagiotis Koulouvaris and Giorgos Paradisis

The aim of this study was to examine the relationship between the mechanical characteristics of the horizontal and vertical Force-velocity (F-v) profile as well as the performance variables of the sprinting and jumping testing procedures. Twenty high-level sprinters performed two maximal sprints and squat jumps against multiple external loads. Our main findings revealed very large correlations for maximal mechanical power output (Pmax) (r=0.72), as well as for performance variables between the sprinting and jumping tasks (r=-0.81) and large correlations for maximal velocity (V0) (r=0.66). The maximal force (F0) and the slope of the F-v relationship (F-v slope) were not significantly correlated
between both tasks. These results suggest that both testing procedures should be performed in order to gain a deeper insight into the maximal mechanical properties and function of the lower-body muscles in high-level sprinters.

 

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Efect of a home‑based exercise training program on anthropometric characteristics and exercise performance during Covid‑19 quarantine in young high‑level kayak athletes

 

Charilaos Tsolakis, Evgenia D. Cherouveim, Athanasios Viliotis, Theocharis Simeonidis, Apostolos Skouras, Panagiotis Koulouvaris

Abstract
Purpose The Covid-19 restriction exposed most athletes to insufcient training stimuli leading to detraining. This study investigated whether a home-based exercise training program could preserve body composition and exercise performance in young high-level kayak athletes during Covid-19 restriction.
Methods Seventeen healthy young high-level kayak athletes (10 males and 7 females), aged 14.7±1 yrs, participated in this study. A 7-week home-based training program was followed during Covid-19 restriction. Baseline measurements were assessed 4 weeks before Covid-19 pandemic and ended on 4 May 2020. Body composition, fexibility, isometric muscle trunk strength (Biodex), anaerobic power (30-s all-out trial), and aerobic capacity (4-min maximal test) were evaluated. Personal daily loads and wellness details were collected with AthleteMonitoring.com software.
Results Home-based exercise training program was efective to improve fexibility (9.20±2.85%) and lean body mass (3.96±0.89%), to maintain muscle strength, anaerobic power, body mass, and body fat percentage but insufcient to maintain aerobic capacity (− 8.96±2.49%).
Conclusion The fndings of the present study potentially highlight the importance of the implementation of such a program to minimize the detraining efect on young athletes during periods of movement restriction caused by pandemics.

 

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The Effects of High-Intensity Interval Exercise on Skeletal Muscle and Cerebral Oxygenation during Cycling and Isokinetic Concentric and Eccentric Exercise

Panagiotis A. Perentis, Evgenia D. Cherouveim, Vassiliki J. Malliou, Nikos V. Margaritelis, Panagiotis N. Chatzinikolaou, Panayiotis Koulouvaris, Charilaos Tsolakis, Michalis G. Nikolaidis, Nickos D. Geladas and Vassilis Paschalis

 

Abstract: The aim of the present study was to study the effects of cycling and pure concentric and pure eccentric high-intensity interval exercise (HIIE) on skeletal muscle (i.e., vastus lateralis) and cerebral oxygenation. Twelve healthy males (n = 12, age 26 ± 1 yr, body mass 78 ± 2 kg, height 176 ± 2 cm, body fat 17 ± 1% of body mass) performed, in a random order, cycling exercise and isokinetic concentric and eccentric exercise. The isokinetic exercises were performed on each randomly selected leg. The muscle and the cerebral oxygenation were assessed by measuring oxyhemoglobin, deoxyhemoglobin, total hemoglobin, and tissue saturation index. During the cycling exercise, participants performed seven sets of seven seconds maximal intensity using a load equal to 7.5% of their body mass while, during isokinetic concentric and eccentric exercise, they were performed seven sets of five maximal muscle contractions. In all conditions, a 15 s rest was adopted between sets. The cycling HIIE caused greater fatigue (i.e., greater decline in fatigue index) compared to pure concentric and pure eccentric isokinetic exercise. Muscle oxygenation was significantly reduced during HIIE in the three exercise modes, with no difference between them. Cerebral oxygenation was affected only marginally during cycling exercise, while no difference was observed between conditions. It is concluded that a greater volume of either concentric or eccentric isokinetic maximal intensity exercise is needed to cause exhaustion which, in turn, may cause greater alterations in skeletal muscle and cerebral oxygenation.

 

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Skeletal muscle and cerebral oxygenation levels during and after submaximal concentric and eccentric isokinetic exercise

 

Evgenia Cherouveim, Nikos Margaritelis, Panagiotis Koulouvaris, Charis Tsolakis, Vasiliki Malliou, Panagiotis Chatzinickolaou, Martino Franchi, Simone Porcelli, Antonios Kyparos, Ioannis Vrabas, Nikos Geladas, Michalis Nikolaidis, Vassilis Paschalis, PhD

 

Abstract: The aim was to investigate the potential differences in muscle (vastus lateralis) and cerebral (prefrontal cortex) oxygenation levels as well as in the number of repetitions and total work output between isokinetic eccentric and concentric exercise at a moderate relative intensity until exhaustion. Ten recreationally active young men underwent two isokinetic exercise sessions either concentric or eccentric, one on each randomly selected leg. The protocols were performed at 60°/s and an intensity corresponding to 60% of the maximal voluntary contraction (MVC) of each contraction type. Concentric torque was significantly lower compared to eccentric torque in both peak values and at values corresponding to 60% of MVC [230±18Nm vs. 276±19Nm (P=.014) and 137±12Nm vs. 168±11Nm, respectively (P=.010)]. The participants performed 40% more contractions during eccentric compared to concentric exercise [122±15 vs. 78±7, respectively]. No differences were found in the levels of oxyhemoglobin, deoxyhemoglobin, total hemoglobin and tissue saturation index when eccentric and eccentric exercise regimes were compared (all P>0.05). Our results demonstrate that eccentric exercise of moderate intensity leads to greater resistance to fatigue and more work output compared to concentric exercise, despite the comparable muscle and cerebral oxygenation levels.

 

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The adjunctive benefits of mirror cross education on kinetic chain exercise approach in volleyball athletes with scapular dyskinesis

 

Eleftherios Paraskevopoulos, Theocharis Simeonidis, Charilaos Tsolakis, Panagiotis Koulouvaris, Maria Papandreou

 

Abstract
Background: Volleyball players as overhead athletes have the highest risk of developing scapular dyskinesis. The kinetic chain exercise-approach has gained a lot of attention because of its claims to provide an improved motor control and scapular kinematics. A form of cross exercise, known as mirror therapy, may enhance the effects of a kinetic-chain-approach on scapular posture, upper and lower limb performance. The aim of this study was to investigate the adjunctive benefits of mirror cross education in a kinetic chain approach, in volleyball athletes with SD.

Methods: Thirty-nine professional volleyball athletes were randomly assigned to three groups of 13 each, two experimental, the mirror cross education and kinetic chain approach, and one control. Both experimental groups performed a kinetic chain approach program, however, the mirror cross education group performed the exercise program with the addition of two mirrors that allowed athletes to observe their opposite non-dyskinetic scapula. Scapular posture asymmetries in cm, the YBalance and the Upper-Quarter Y-Balance after normalizing by limb length the reach distance in each direction, were assessed before and after performing each intervention for 6 weeks.

Results: 3×2 two-way Mixed ANOVAs detected significant interactions on scapular posture (P=0.001) on both experimental groups when compared with the control. The Y-Balance and the Upper Quarter Y-Balance scores at both mirror cross education and kinetic chain approach groups showed significant differences when compared with the control (P<0.05). Overall, variables showed significant superiority
of the mirror cross education group.

Conclusions: The Mirror-Cross-Education demonstrated significant effects in scapular posture and in the functional balance tests of volleyball athletes with scapular dyskinesis.

 

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Mirror Cross-Exercise on a Kinetic Chain Approach Improves Throwing Performance in Professional Volleyball Athletes With Scapular Dyskinesis

 

Eleftherios Paraskevopoulos, Theocharis Simeonidis, Charilaos Tsolakis, Panagiotis Koulouvaris, and Maria Papandreou

 

Abstract

Context: Volleyball players have shown to be at an increased risk of developing scapular dyskinesis. The kinetic chain exercise approach has gained a lot of attention because of its claims to provide an improved motor control and scapular kinematics. A form of cross exercise, known as mirror therapy, may enhance the effects of a kinetic chain exercise approach in throwing performance. Objective: To examine the effects of mirror cross exercise (MCE), based on a kinetic chain exercise approach in the throwing performance of volleyball athletes with scapular dyskinesis. Design: Randomized controlled trial. Setting: Biomechanics laboratory. Methods: 39 volleyball players with scapular dyskinesis were randomly allocated into 3 groups. The first group completed a 6-week kinetic chain approach (KCA group), the second group completed a kinetic chain exercise approach program in addition to MCE group, and the control group followed only their regular training program. Before and after delivering both interventions, throwing accuracy, speed, and force were determined while measuring the ground reaction forces of the drive leg during throwing. Two-way mixed analysis of variance investigated the effects of intervention and time and their interaction. Results: The results showed intervention × time statistically significant interactions for throwing accuracy, speed, and force for the MCE and the KCA groups. Over the 6-week training period, the MCE and the KCA groups showed significant improvements in throwing accuracy (P < .01) and speed (P < .01), while the ground reaction forces did not change (P > .05). Throwing force increased significantly in the MCE group (P = .01). Between-group comparison showed statistically significant improvements in the throwing accuracy for the MCE and KCA groups against the control group (P < .01) at posttesting. The MCE demonstrated superior results over the KCA in the aforementioned measures. Conclusions: This study suggests that the addition of MCE in a KCA program enhances energy transfer throughout the distal and proximal segments, thus improving kinetic chain recruitment and potentially preventing shoulder pathology.

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The effect of gender, age and sports specialisation on isometric trunk strength in Greek high level young athletes

 

Charilaos Tsolakis, Theoharis Simeonidis, Panagiotis Georginis, Evgenia Cherouveim, Spyridon Methenitis & Panagiotis Koulouvaris

 

Aim of the study was to compare the isometric strength of flexors and extensors trunk muscles between male and female elite adolescent athletes of different age and training experience. Absolute and relative trunk muscle isometric peak extension (PTE) and flexion (PTF) torque, as well as flexion/extension (F/E) ratio were evaluated in 388 elite adolescent athletes 188 males (Age: 15.4±1.8 years, Body height: 175.5±11.2 cm, Body mass: 68.8±14.5 kg, BMI: 22.1±0.3 kg/m2) and 207 females (Age: 15.1±1.6 years, Body height: 166.8±7.8 cm, Body mass: 60.8±8.4 kg and BMI: 21.8±0.4 kg/m2). Participants were assigned into seven different groups according to their sport specialisation (oars-paddle, swimming, contact–combat, team, racket, winter and mixed other sports). Significant effect of age (η2: 0.077–0.112, p < 0.05), gender (η2: 0.020–0.077; p < 0.05) and sport category factors (η2: 0.057–0.154. p < 0.005) for absolute/relative PTE, PTF and F/E ratio was found. The highest values were observed in contact–combat and the lowest in mixed other sports groups. F/E ratio significantly differs between the age groups, especially in female athletes. The present data suggest that TMSs and F/E ratio are highly affected by age, gender and sports specialisation in high level trained adolescents.

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Koulouvaris P, Tsolakis C, Tsekouras YE, Donti O, Papagelopoulos PJ. Obesity and physical fitness indices of children aged 5-12 years living on remote and isolated islandsRural Remote Health. 2018;18(2):4425. doi:10.22605/RRH4425

Η παιδική παχυσαρκία είναι μια σύγχρονη μάστιγα, η οποία περιορίζει την φυσική κατάσταση των παιδιών και επηρεάζει την υγεία τους. Η παιδική παχυσαρκία γνωρίζαμε, ότι εμφανίζεται σε υψηλότερες τιμές στις αστικές περιοχές, ενώ από τα αποτελέσματα της μελέτης του Sports Excellence σε 463 παιδιά Δημοτικού Σχολείου σε 18 ακριτικά νησιά της Ελλάδος διαπιστώθηκε ότι η παχυσαρκία είναι, επίσης, εμφανής και μάλιστα είχε παρόμοιες τιμές με αυτές των αστικών περιοχών. Αποτέλεσμα αυτών των παρατηρήσεων ήταν ότι το 50-75% των παιδιών είχαν μειωμένη απόδοση σε δοκιμασίες φυσικής κατάστασης των παιδιών σύμφωνα με τις νόρμες της μελέτης του Ευ ζην. Οι περιοχές αυτές χρήζουν ενημέρωσης και παρεμβάσεων άσκησης και διατροφής όχι μόνο στο περιβάλλον του σχολείου αλλά και στις εξωσχολικές ώρες, ώστε να αντιστραφεί η σημερινή εικόνα και να υπάρξει μακροπρόθεσμη βελτίωση της υγείας των παιδιών.

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 https://www.rrh.org.au/journal/article/4425

Obesity has become one of the major health risks in childhood, significantly affecting children’s health and physical fitness. Although the marked increase of obesity in urban areas is well established, evidence is limited in remote and isolated areas with adverse socioeconomic features. The aim of this study was to examine the prevalence of obesity and its association with physical performance indices in young school-aged children living in 18 remote and isolated Greek islands.

Methods:  Four hundred and sixty-three children (244 boys, 219 girls), aged 5–12 years underwent a series of physical fitness tests including 20 m sprint, standing long jump, 1 kg medicine ball throw, agility T-test and sit-and-reach test. Age and gender BMI cut-off points were determined according to World Health Organisation (WHO) norms.

Results:  The prevalence of obesity was 23.8% and 13.2% for boys and girls, respectively. A negative body mass index (BMI) main effect was observed for weight-bearing activities, such as 20 m sprint (F=6.21, p=0.000, η2=0.041) and standing long jump (F=11.369, p=0.000, η2=0.074), while medicine ball throw was positively correlated with BMI in children aged 9–12 years.
Conclusion:  The results of this study confirmed previous findings on obesity prevalence in Greece. A negative association was also found between BMI and physical fitness indices and, in particular, in weight-bearing activities. It is critical to establish physical education interventions and physical fitness programs at schools, aiming to increase motivation for physical activity participation.

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 https://www.rrh.org.au/journal/article/4425

Charilaos Tsolakis(1), Yiannis E. Tsekouras(2), Theodoros Daviotis(2), Panayiotis Koulouvaris(2), Panayiotis J. Papaggelopoulos(2)
(1) School of Physical Education and Sports Science, National Kapodistrian University of Athens, Greece
(2) 1st Orthopaedic Clinic «Attikon» General University Hospital, Orthopaedic Center of Research and Education PN Soukakos, Attikon Hospital, National Kapodistrian University of Athens, Greece

Στη σύγχρονη προπονητική είναι σημαντικό να γνωρίζουμε με ακρίβεια ποιές μεταβλητές της φυσικής κατάστασης επηρεάζουν την αγωνιστική απόδοση. Στο άρθρο αυτό οι συγγραφείς επιδιώκουν να διερευνήσουν την σχέση της ισχύος των κάτω άκρων με την απόδοση βασικών κινητικών δεξιοτήτων (βήμα-προβολή) που χρησιμοποιούν οι αθλητές ξιφασκίας κατά την αγωνιστική προσπάθεια. Η αλληλεπίδραση μεταξύ των μεταβλητών απόδοσης, η ενεργοποίηση πολλών μυικών ομάδων, η μηχανική των κινήσεων των βασικότερων κινητικών δεξιοτήτων, η ύπαρξη αντιπάλου, και η τακτική συνιστούν την ενδελεχή μελέτη της αγωνιστικής προσπάθειας στην ξιφασκία. Από τα αποτελέσματα της μελέτης φαίνεται ότι τα ανθρωπομετρικά χαρακτηριστικά δεν επηρεάζουν την απόδοση σε νεαρή ηλικία. Αντιθέτως η ισχύς των κάτω άκρων σε κατακόρυφη και οριζόντια διεύθυνση ερμηνεύουν την απόδοση στην κίνηση του βήματος-προβολής και των αλλαγών κατεύθυνσης στην αγωνιστική ξιφασκία.

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ABSTRACT

The aim of this study was to investigate sport specific correlates of fencing performance, in both young male and female fencers. All assessments (anthropometry, arm strength, leg power, flexibility, fencing movement reaction times in visual stimuli velocity of arm extension, lunge velocity, step and lunge velocity and fencing specific agility test) were conducted on 9 males and 13 female young fencers 13.4±0.85 years old (mean age
± standard deviation). Relationships were examined by calculating Pearson’s product moment correlation coefficient (r). A stepwise multiple linear regression was used to identify the best predictors of fencing performance. Females were found to have more body fat and higher BMI values compared to males. Males outperformed females in all leg power tests, while females were more flexible than males. Moreover males were faster in arm velocity, step-lunge velocity and change of direction velocity compared to females. Anthropometric parameters were not correlated to fencing performance. Long jump and squat jump were the best predictors of step and lunge velocity and change of direction velocity, respectively. The integration of power exercises in both the horizontal and vertical plane is recommended as regular regimen in physical condition protocols in order to optimize the fencing performance in young fencers.

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Charilaos Tsolakis ,Theoharis Simeonidis,Panagiotis Georginis,Evgenia Cherouveim,Spyridon Methenitis, Panagiotis Koulouvaris.

 

Σκοπός της παρούσας μελέτης ήταν να συγκριθεί η ισομετρική δύναμη κορμού μεταξύ ανδρών και γυναικών αθλητών υψηλού επιπέδου διαφορετικής ηλικιακής κατηγορίας και προπονητικής εμπειρίας. Μέθοδος: Συνολικά, 388 έφηβοι αθλητές, υψηλού επιπέδου ,συμμετείχαν εθελοντικά σε αυτήν την έρευνα. Οι 188 ήταν άνδρες (Ηλικία: 15.4±1.8 ετών, Σωματικό Ανάστημα 175.5±11.2 cm, Σωματικό Βάρος 68.8±14.5 kg, ΒΜΙ: 22.1±0.3 kg/m2) και οι 207 γυναίκες (Ηλικία: 15.1±1.6 ετών, Σωματικό Ανάστημα 166.8±7.8 cm, Σωματικό Βάρος 60.8±8.4 kg, ΒΜΙ: 21.8±0.4 kg/m2). Οι αθλητές/τριες ταξινομήθηκαν σε εφτά (7) διαφορετικές ομάδες σύμφωνα με την αθλητική ειδίκευση (αθλήματα κωπηλασίας και κανό καγιάκ, κολύμβησης, μαχητικά αθλήματα, ομαδικά, ρακέτας, χειμερινά και λοιπά αθλήματα). Οι αθλητές αξιολογήθηκαν στην μέγιστη ισομετρική δύναμη εκτεινόντων (ΡΤΕ) και καμπτήρων (ΡΤF) μυών κορμού με το ισοκινητικό δυναμόμετρο Biodex (Biodex Pro 4, Biodex Medical Systems, Inc, USA). Επιπλέον, η αναλογία δύναμης μεταξύ κάμψης / έκτασης (F/E) υπολογίστηκε. Αποτελέσματα: Παρατηρήθηκαν σημαντικές διαφορές μεταξύ ηλικίας (η2: 0.077-0.112, p<0.05), φύλου (η2: 0.020-0.077, p<0.05) και αθλητικής ειδίκευσης (η2: 0.057-0.154, p<0.005) για την απόλυτη και σχετική μέγιστη ΡΤΕ, PTF καθώς και αναλογίας F/E. Οι υψηλότερες τιμές παρατηρήθηκαν στους αθλητές/τριες των μαχητικών αθλημάτων, ενώ οι χαμηλότερες στην ομάδα των υπολοίπων αθλημάτων. Επιπλέον, παρατηρήθηκε σημαντική διαφοροποίηση στην αναλογία F/E μεταξύ των ηλικιακών ομάδων, ιδιαίτερα για τις αθλήτριες. Συμπεράσματα: Τα δεδομένα της παρούσας μελέτης έδειξαν ότι η δύναμη κορμού και η αναλογία κάμψης / έκτασης επηρεάζονται σημαντικά από την ηλικία, το φύλο και την αθλητική ειδίκευση σε έφηβους αθλητές υψηλού επιπέδου.

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EVGENIA CHEROUVEIM1, CHARILAOS TSOLAKIS2 CHRISTOS NTOZIS3, NIKOLAOS APOSTOLIDIS4, KONSTANTINOS GKOUNTAS5, PANAGIOTIS KOULOUVARIS6

Sports Excellence, 1st Orthopedics Department, School of Health Sciences, National and Kapodistrian University of Athens, GREECE ,School of Physical Education & Sports Science, National and Kapodistrian University of Athens, GREECE; 3,5Hellenic Volleyball Federation, GREECE

Εισαγωγή. Παρά τη διαφοροποίηση των ανθρωπομετρικών χαρακτηριστικών και φυσιολογικών απαιτήσεων σύμφωνα με τις τεχνικές και τακτικές απαιτήσεις της κάθε θέσης παιχνιδιού σε ενήλικους αθλητές της πετοσφαίρισης, ελάχιστες είναι οι έρευνες που έχουν εξετάσει το παραπάνω ζήτημα σε νεαρές αθλήτριες της πετοσφαίρισης. Συνεπώς, σκοπός αυτής της μελέτης ήταν να διερευνηθεί η επίδραση της θέση του παιχνιδιού και της ηλικίας στα ανθρωπομετρικά χαρακτηριστικά και στην απόδοση σε νεαρές αθλήτριες της πετοσφαίρισης. Μέθοδος. Συνολικά 389 υγιείς γυναίκες (n = 389, 14,2 ± 5,5 ετών, σωματική μάζα 57,05 ± 9,48 kg, ύψος 1,67 ± 0,07 m και δείκτης μάζας σώματος 20,28 ± 2,76), αθλήτριες υψηλού επιπέδου της πετοσφαίρισης συμμετείχαν εθελοντικά σε αυτήν τη μελέτη. Οι συμμετέχοντες χωρίστηκαν σε έξι ομάδες ανάλογα με τη θέση παιχνιδιού τους [setters (n = 66), out-hitters (n = 125), mid-blockers (n = 66), opposites (n = 37), liberos (n = 25)], και χωρίς εξειδικευμένη θέση (n = 70)] και σε δύο ηλικιακές ομάδες [13 (AG13, n = 127) και 14 (AG14, n = 262) ετών]. Σε όλες τις αθλήτριες προσδιορίστηκαν τα ανθρωπομετρικά χαρακτηριστικά και η δοκιμασία απόδοσης σε γηπεδικές αξιολογήσεις. Συγκεκριμένα, οι αθλητές εκτέλεσαν τις παρακάτω δοκιμασίες: ρίψη ιατρικής μπάλας (MBT), άλμα άνευ φόρας (LJ), άλμα με προφόρτιση (CMJ), άλμα καρφώματος (SJ), ευλυγισία (SRT), ευκινησία (AΤ) και δύναμη κορμού (SU). Αποτελέσματα. Παρατηρήθηκε σημαντική διαφορά (p <0,05) μεταξύ των θέσεων παιχνιδιού αναφορικά με τα ανθρωπομετρικά χαρακτηριστικά και την απόδοση στις γηπεδικές αξιολογήσεις. Συγκεκριμένα, οι αθλήτριες χωρίς εξειδικευμένη θέση παιχνιδιού είχαν μικρότερα σωματομετρικά χαρακτηριστικά και χαμηλότερη απόδοση άσκησης (MBT, LJ, CMJ, SJ, SRT, AT και UP) σε σύγκριση με τις αθλήτριες των υπολοίπων θέσεων παιχνιδιού. Ωστόσο, η δοκιμασία απόδοσης ήταν παρόμοια (p> 0,05) μεταξύ των αθλητριών με εξειδικευμένες θέσεις παιχνιδιού. Αναφορικά με την ηλικία, υπήρξε σημαντική επίδραση στην δοκιμασία απόδοσης, με τις μέσες τιμές των αξιολογήσεων LJ, CMJ, SJ, MBT και SRT να είναι μεγαλύτερες στην ηλικιακή ομάδα των 14 ετών από ό,τι στην νεώτερη ηλικιακή ομάδα, ενώ η απόδοση στη δύναμη του κορμού να είναι υψηλότερη στην ηλικιακή ομάδα των 13 ετών σε σχέση με την ηλικιακή ομάδα των 14 ετών. Επιπλέον, παρατηρήθηκαν σημαντικές συσχετίσεις μεταξύ αλτικής ικανότητας και ανθρωπομετρικών χαρακτηριστικών. Συμπεράσματα. Τα αποτελέσματα αυτής της μελέτης μπορούν να χρησιμοποιηθούν ως τιμές αναφοράς κατά τη διαδικασία επιλογής ταλέντων για την παροχή συγκεκριμένων δεδομένων ανά θέσης παιχνιδιού για αυτήν την ηλικιακή ομάδα. Η έλλειψη φυσιολογικών διαφορών μεταξύ των θέσεων παιχνιδιού επιβεβαιώνει ότι τα ανθρωπομετρικά χαρακτηριστικά μπορεί να είναι ένας κρίσιμος παράγοντας ταυτοποίησης για την κύρια επιλογή ταλέντων για αυτήν την ηλικιακή ομάδα.

 

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Drakoulaki Vasiliki, Kontochristopoulos Nikolaos, Methenitis Spyridon, Georginis Panagiotis, Cherouveim Evgenia, Koulouvaris Panagiotis, Tsolakis Charilaos. Bilateral asymmetries in male and female young elite fencers in relation to fencing performance. Isokinetics and Exercise Science, 2020, 1-9, doi: 10.3233/IES-202200.

Υπόβαθρο: Τα δεδομένα σχετικά με τη δύναμη των κάτω άκρων, τις ασυμμετρίες στην ικανότητα παραγωγής ισχύος στους ξιφομάχους και τις σχέσεις τους με την αγωνιστική απόδοση στην ξιφασκία είναι περιορισμένα και ασυνεπείς. Σκοπός: Ο στόχος της παρούσας μελέτης ήταν να διερευνήσει τις ασυμμετρίες, μεταξύ κυρίαρχου (D) και μη-κυρίαρχου (ND) ποδιού σε νεαρούς κορυφαίους, άνδρες και γυναίκες, ξιφομάχους, σε σχέση με την απόδοση σε ειδικές αξιολογήσεις του αγωνίσματος της ξιφασκίας. Μέθοδος: Τα ανθρωπομετρικά χαρακτηριστικά, η επίδοση στα μονοποδικά οριζόντια και κάθετα άλματα, η μέγιστη ισοκινητική δύναμη, οι επιδόσεις στην κίνηση προβολής και βήμα – προβολής αξιολογήθηκαν σε 16 άνδρες και 22 γυναίκες υψηλού επιπέδου ξιφομάχους. Αποτελέσματα: Παρατηρήθηκαν σημαντικές διαφορές μεταξύ των δύο φύλων για όλα τα ανθρωπομετρικά χαρακτηριστικά (p <0.05). Δεν παρατηρήθηκαν σημαντικές διμερείς ασυμμετρίες και δεν διαπιστώθηκε επίδραση του παράγοντα φύλου x πλευρικότητας (p> 0.05). Η απόδοση στην ξιφασκία συσχετίστηκε αρνητικά με την λόγο της μέγιστη δύναμης κατά την κάμψη / έκταση (F/E) του κυρίαρχου σκέλους στις 300 °/s (r: -0.564 έως -0.619, p <0.05). Επιπλέον, ο λόγος F/E του κυρίαρχου σκέλους στις 300 °/s συσχετίστηκε θετικά με την ταχύτητα και την ισχύ στις ειδικές αξιολόγησης απόδοσης της ξιφασκίας στις γυναίκες (r: 0.562-0.649, p <0.05). Τέλος, μόνο στις γυναίκες ξιφομάχους, η απόσταση κατά την αξιολόγηση των μονοποδικών αλμάτων εις τριπλούν συσχετίστηκε σημαντικά με την ταχύτητα και την ισχύ στις ειδικές αξιολόγησης απόδοσης της ξιφασκίας (r: 0.444-0.500, p <0.05). Συμπεράσματα: Τα αποτελέσματα της παρούσας μελέτης υποδηλώνουν ότι το διαφορετικό μοτίβο ενεργοποίησης / κίνησης κατά την ξιφασκία μεταξύ των μυών του κυρίαρχου και του μη κυρίαρχου ποδιού των ξιφομάχων δεν οδηγεί σε ανατομικές, δυναμικές και λειτουργικές ασυμμετρίες των κάτω άκρων.

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Validity and Reliability of New Equations for the Prediction  of Maximal Oxygen Uptake in Male and Female Elite Adolescent Rowers

 

Evgenia D. Cherouveim, Spyridon K. Methenitis, Theocharis Simeonidis, Panagiotis Georginis, Yiannis E. Tsekouras, Chrisa Biskitzi, Charis Tsolakis, Panagiotis Koulouvaris

 

The aim of this study was to develop accurate, reliable, and reproductive equations for the prediction of maximum oxygen uptake in male and female high-level adolescent rowers. This study included two parts. In the first part,Vo2Max was evaluated in 106 male and 83 female high-level adolescent rowers during an incremental step test (IRT) on a rowing ergometer, and stepwise multiple regression analyses were used for the development of new equations. In the second part, these equations were tested in 26 new high-level adolescent rowers of the same age and anthropometrical characteristics (boys: 15.27 ± 2.70 yrs and 15.34 ± 2.80 yrs; 72.37 ± 10.96 kg and 70.96 ± 10.65 kg; girls: 15.00 ± 2.11 yrs and 15.94 ± 2.71 yrs; 62.50 ± 7.14 kg and 63.41 ± 6.72 kg for parts 1 and 2, respectively; p > 0.05). Vo2Max was predicted from the combination of lean body mass (LBM) and the distance covered during the last 4 min stage of the IRT (boys: r2 = 0.715, F = 68.74, p = 0.001; girls: r2 = 0.769, F = 57.81, p = 0.001). In the second part, no significant differences were identified when the new equations were tested against measured Vo2Max (boys: 3971.15 ± 713.38 mL·min−1 vs.3915.83 ± 704.43 mL·min−1; girls: 3272.75 ± 551.46 mL·min−1 vs. 3308.94 ± 557.59 mL·min−1 for measured and predicted values, respectively; p > 0.05). In conclusion, Vo2Max of high-level adolescent rowers can be predicted with high accuracy, reliability, and repeatability using simple and easily evaluated anthropometric and performance variables.

 

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Exploring the predictors and prognostic significance of exercise-induced cardiac troponin release in master athletes following a 28 km mountain race. The Vamvakou research project

 

George Stavroulakis, Spyridon Methenitis, George Koutroulis, Dimitrios Xanthis, Eugenia Cherouveim, Christos Kroupis, George Anastasiadis, Kleopatra Ketselidi, Elpiniki Vlachopoulou, Charilaos Tsolakis & Panagiotis Koulouvaris

 

Background/objective

Aetiology and significance of exercise-induced troponin release remains a contentious issue. We investigated the effect of a 28 km mountain run on cardiac troponin I (cTnI), in relation to training, performance, nutritional, biochemical and echocardiography variables, in a group of 25 recreational male master athletes.

Material and methods

A comprehensive list of variables related with nutrition, training, performance and echocardiography, was collected pre- and post-race. Twenty-four months later, outcomes regarding cardiovascular events were obtained.

Results

Serum cTnI values were increased after the race, with mean values rising from 7.2 ± 2.2 (before) to 80.0 ± 33.2 ng/L (post race), (p < 0.001) and 23/25(92%) exceeding Upper Reference limit (50 ng/L). Echocardiography did not reveal significant alterations, or correlations with cTnI values. The percentage difference in hs-cTnI concentrations pre- and post-race correlated positively with age, race-induced changes of selected muscle damage indices, resistance training volume and negatively with endurance capacity and training volume (r: −0.727 to 0.725, p < 0.05). All athletes reported no cardiovascular event during the 24-month period post-race.

Conclusion

cTnI elevation induced by a 28 km mountain running race was not correlated with echocardiographic, nutritional parameters and was less pronounced in athletes with larger endurance training history, in contrast with resistance training and age.

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Anthropometric and physiological characteristics of 13–14-year-old female  volleyball players in different playing positions

EVGENIA CHEROUVEIM, CHARILAOS TSOLAKIS, CHRISTOS NTOZIS, NIKOLAOS APOSTOLIDIS, KONSTANTINOS GKOUNTAS, PANAGIOTIS KOULOUVARIS

 

Abstract
Introduction: Despite the differentiation of anthropometric and physiological demands according to the  technical and tactical requirements of each playing positionin adults, only few studies have examined this issue  in young female volleyball players. Thus, the aim of this study was to investigate the effects of playing  positions and age on anthropometric characteristics and exercise performance in young female volleyball players.

Material and Methods:A total of 389 healthy females (n = 389, 14.2 ± 5.5 years old, body mass of  57.05 ± 9.48 kg, height of 1.67 ± 0.07 m, and body mass index of 20.28 ± 2.76), who are high-level volleyball players, volunteered to participate in this study. Participants were divided into six groups according to their playing position [i.e., setters (n = 66), outside-hitters (n = 125), middle blockers (n = 66), opposites (n = 37), liberos (n = 25), and without a specific position (n = 70)] and into two age groups [i.e., 13 (AG13, n = 127) and
14 (AG14, n = 262) years old]. All athletes were assessed for anthropometric characteristics and physical performance. Specifically, athletes completed overhead medicine ball throw (MBT), standing long jump (LJ),countermovement jump (CMJ), spike jump (SJ), flexibility, agility T-test, and sit-ups (SU) trials.

Results:There was a significant difference (p < 0.05) among playing positions in terms of anthropometrics and exercise performance. Specifically, volleyball players without a specific playing position had a smaller body morphology and lower exercise performance (in MBT, LJ, CMJ, SJ, SRT, AT, and UP) compared to other playing positions. However, physiological characteristics were similar (p>0.05) among volleyball players with specific playing positions. Regarding age, there was a significant effect on exercise performance, and the mean values of LJ, CMJ, SPJ, MBT, and agility test were higher in olderathletes than in younger ones; whereas sit-ups values were higher in younger players than in older ones. Significant correlations were observed between jumping ability and anthropometric characteristics.

Conclusion: The results of this study can be used as reference values during the talent selection process to provide specific playing position data for this age-group category.The lack of physiological differences among playing positions confirms that anthropometric characteristics can be an adequate identification factor for the primary talent selection for this age group.

 

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The Impact of Obesity on the Fitness Performance of School-Aged Children Living in Rural Areas—The West Attica Project

Charilaos Tsolakis, Evgenia D. Cherouveim, Apostolos Zacharias Skouras, Dimitrios Antonakis-Karamintzas, Cara Czvekus, Panagiotis Halvatsiotis, Olga Savvidou and Panagiotis Koulouvaris

Abstract: This study aimed to investigate the relationship of body mass index (BMI) with muscle and cardiorespiratory fitness in children living within rural areas (regional unit of West Attica) in Greece. Participants included 399 students (187 boys, 212 girls), ages 8–12 years old, and were evaluated in physical performance tests. The point prevalence of overweight and obesity was 21.39% and 26.20% in boys, and 19.90% and 23.79% in girls. Significant differences were observed in all physical performance tests (handgrip, long jump, shuttle run, trunk flexors, and extensors endurance) between normal weight and obese participants. BMI was positively correlated with handgrip (r = 0.442−0.462, p < 0.001). There was a negative association with long jump (r = −0.206, p < 0.001), 20 m shuttle run (r = −0.394, p < 0.001), trunk flexors (r = −0.403, p < 0.001) and trunk extensors endurance (r = −0.280, p < 0.001). The regression analysis showed that 20–30% of the overall variation for physical performance assessments could be accounted for by BMI, age, and sex. With the exception of the long jump and the endurance of the trunk extensors, BMI alone may explain more than 10% of the outcome of most tests. This study highlights the determinant of BMI on muscle and cardiorespiratory fitness. The management of obesity should begin early in childhood to prevent
adult chronic cardiovascular and metabolic diseases.

 

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