Ioannis Bayios | National & Kapodistrian University of Athens (original) (raw)

Papers by Ioannis Bayios

A digital electronic device was constructed in order to measure the accuracy of throwing in handb... more A digital electronic device was constructed in order to measure the accuracy of throwing in handball. This innovative device consists of two parts: a) the central unit which generates visual stimuli and collects data and b) tabloids. HARDWARE AND SOFTWARE SPECIFICATION: The device consists of three independent tabloids placed inside and connected to the handball goal post. The dimensions of the two vertical tabloids are 200x60x2cm, and those of the horizontal 180´60´2cm. The dimensions of the goal post are 300´200´8 cm, constituting a total surface of 60,000 cm2, of 38,400 cm2 are covered by the tabloids. A total of 2,130 holes were made in all three tabloids. The same number of light emitting diodes (LED) were placed on the back side of each tabloid in each hole so that they would be visible on the front side. The LED’s were placed in such a way as to form a net of squares (40´40mm). One of these squares, when lit up, determined the ‘target-point’ to be hit in a throw (shot). The n...

The Journal of sports medicine and physical fitness

Aim. The purpose of the study was to identify the playing level (Under 16: U16, Under 18: U18 and... more Aim. The purpose of the study was to identify the playing level (Under 16: U16, Under 18: U18 and Under 20: U20) and the playing position (Goalkeepers, Backs, Wings, Pivots, Centers) differences of elite junior handball players expressed in the anthropometric and physical fitness characteristics. Methods. The anthropometric characteristics of body height, arm span, hand length, hand width, body mass, adipose tissue percentage, somatotype components and the physical fitness characteristics of ball throwing velocity, sprinting time, standing long jump, aerobic capacity, lower back and hamstring flexibility were measured in a total of sixty (60) handball players all members of the Greek Junior National Teams. Results. There were significant (P <= 0.05) differences among playing levels regarding hand length, hand width, ball velocity (U18>U16), body mass, ball velocity and standing long jump (U20>U16). Significant differences among playing positions (P <= 0.05) were found fo...

Medicine & Science in Sports & Exercise

International Journal of Performance Analysis in Sport

Journal of sports science & medicine, 2016

The fatiguing effect of long-distance running has been examined in the context of a variety of pa... more The fatiguing effect of long-distance running has been examined in the context of a variety of parameters. However, there is scarcity of data regarding its effect on the vertical jump mechanics. The purpose of this study was to investigate the alterations of countermovement jump (CMJ) mechanics after a half-marathon mountain race. Twenty-seven runners performed CMJs before the race (Pre), immediately after the race (Post 1) and five minutes after Post 1 (Post 2). Instantaneous and ensemble-average analysis focused on jump height and, the maximum peaks and time-to-maximum peaks of: Displacement, vertical force (Fz), anterior-posterior force (Fx), Velocity and Power, in the eccentric (tECC) and concentric (tCON) phase of the jump, respectively. Repeated measures ANOVAs were used for statistical analysis (p ≤ 0.05). The jump height decrease was significant in Post 2 (-7.9%) but not in Post 1 (-4.1%). Fx and Velocity decreased significantly in both Post 1 (only in tECC) and Post 2 (both...

Sport Management Review, 2015

Journal of Athletic Enhancement, 2014

The aim of this study was to examine the relationship between Ground Reaction Forces (GRF) and pe... more The aim of this study was to examine the relationship between Ground Reaction Forces (GRF) and performance of throwing above the shoulder towards known and unknown visual target. Fifteen elite handball athletes of the A1 League and 15 physical education students performed in total 10 throwing attempts each, with a cross-over step, under conditions of known and unknown visual target. The foot contact before the throwing attempt was made on an electronic force plate (Kistler, 9281, sampling rate 500 Hz ), whereas ball velocity as well as ball accuracy were measured by using separate specially designed electronic devices. There were no significant differences in the variables of throwing performance between the conditions of known and unknown target, except for the time of foot contact (p<.01). Significant relationships were observed between GRF and throwing performance with regard to the lateral component mainly (ranging from 23.0 to 26.7 % and 27.5 to 33.5 % in the condition of kn...

The Journal of sports medicine and physical fitness, 2007

The purpose of this study was to examine: a) the influence of simulated game activities (SGA) in ... more The purpose of this study was to examine: a) the influence of simulated game activities (SGA) in throwing effectiveness and rotational strength of the shoulder; and b) the relationship between the rotational strength of the shoulder and ball velocity and accuracy in team handball. Sixteen female handball players participated following a SGA, which included distinctive handball activities for 60 min (2 halves of 30 min). For testing ball velocity and accuracy, every 10 min, subjects performed 3 shots on the spot towards a target from 7 m distance. Shoulder isokinetic strength during internal (IR) and external rotation (ER) was evaluated in 3 angular velocities (60, 180, and 300 degrees /s) before SGA, during half-time and at the end of SGA. Throwing effectiveness was significantly affected by time, as aiming accuracy was gradually decreased. However, ball velocity remained stable. The correlation between ball velocity and deviation was not significant throughout the SGA. No statistic...

Journal of science and medicine in sport / Sports Medicine Australia, 2008

The Journal of sports medicine and physical fitness, 2001

The purpose of this study was to examine the relationship between the rotational strength of shou... more The purpose of this study was to examine the relationship between the rotational strength of shoulder and ball velocity in team handball players from various levels. Three groups of young healthy, male subjects took part in the experiments: one group of 15 handball players, the best of League A1 scorers, another group of 12 handball players, the best of League A2 scorers and a random sample of 15 physical education students. Each subject was tested on a Cybex II isokinetic dynamometer. The concentric action of the internal and external rotation of the dominant shoulder was examined at 60, 180 and 300 deg/sec. Ball velocity was examined in three types of throw: (a) on the spot, (b) with a cross-over step, and (c) with a vertical jump. Statistical analysis was performed using the Pearson product-moment correlation and one-way analysis of variance. The differences of peak torque values of the internal and external shoulder rotation between the three groups were not statistically signif...

Journal of Science and Medicine in Sport, 2008

The aim of this study was to describe the morphological characteristics of competitive female vol... more The aim of this study was to describe the morphological characteristics of competitive female volleyball players. For this purpose, body weight and height, breadths and girths as well as skinfold thickness at various body sites were assessed in 163 elite female volleyball players (age: 23.8+/-4.7 years, years of playing: 11.5+/-4.2, hours of training per week: 11.9+/-2.9, means+/-S.D.). Seventy-nine of these players were from the A1 division and the rest from the A2 division of the Greek National League. Two-way ANOVA was used to compare the differences in these characteristics between competition level and playing position. Body height ranged from 161cm to 194cm, and the mean value (177.1+/-6.5cm) was not inferior to that of international players of similar calibre. Adiposity of these players (sum of 5 skinfolds: 51.8+/-10.2mm, percent body fat: 23.4+/-2.8) was higher than that reported in other studies in which, however, different methodology was used. Volleyball athletes of this study were mainly balanced endomorphs (3.4-2.7-2.9). The A1 division players were taller and slightly leaner with greater fat-free mass than their A2 counterparts. Significant differences were found among athletes of different playing positions which are interpreted by their varying roles and physical demands during a volleyball game. The volleyball players who play as opposites were the only subgroup of players differing between divisions; the A2 opposites had more body fat than A1 opposites. These data could be added in the international literature related to the anthropometric characteristics of competitive female volleyball players.

ISBS-Conference …, 2008

METHODS: In order to measure accuracy, an innovative electronic device was used which was placed ... more METHODS: In order to measure accuracy, an innovative electronic device was used which was placed on the inner side of a goal post and functioned as a 'targetpointer' (by means of a red light) and 'hit-detector'. Another lab-made laser device was used for measuring ball ...

International journal of sports physiology and performance, 2008

Handball is a sport with high anaerobic demands in lower body as has been indicated by Wingate te... more Handball is a sport with high anaerobic demands in lower body as has been indicated by Wingate test (WT) performed with the legs, but there are no data available concerning power production during a WT performed with the arms in handball players (HndP). Therefore, the purpose of this study was to explore the arm anaerobic profile of HndP during a WT. Twenty-one elite HndP and 9 physical education students (CON), performed a 30-s arm WT. Power production and muscle oxygenation were recorded. Peak power (PP) as well as mean power (MP) was higher (P = .017 and 0.03, and ES = 1.00 and 0.86, respectively) for HndP (HndP PP: 7.6 +/- 0.8 W x kg(-1); CON PP: 6.7 +/- 1.1 W x kg(-1); HndP MP 5.3 +/- 0.6 W x kg(-1); CON MP 4.7 +/- 0.9 W x kg(-1)) with no significant difference in fatigue index between the two groups. Muscle oxygen saturation (StO2) declined approximately 30% with exercise with no differences between groups. During recovery the HndP group had higher StO2 (P = .01, ES= 3.04), to...

Journal of sports science & medicine, 2013

Dietary supplement (DS) intake is high in elite level athletes, however few studies have investig... more Dietary supplement (DS) intake is high in elite level athletes, however few studies have investigated the impact that the performance level of the athletes has on supplementation intake in individual and team sports. The purpose of the study was to determine and compare the DS intake among individual and team sport athletes of various performance levels. A total of 2845 participants (athletes: 2783, controls: 62) between the ages of 11 and 44 years old participated in the study. A 3-page questionnaire was developed to assess the intake of DS. Athletes were categorized based on participation in individual (n = 775) and team sports (n = 2008). To assess the effect of performance level in supplementation intake, athletes were categorized based on training volume, participation in the national team, and winning at least one medal in provincial, national, international or Olympic games. Overall, 37% of all athletes of various performance levels reported taking at least one DS in the last...

Journal of Human Kinetics, 2011