Ioannis Gissis

Strength and Speed Characteristics of Elite, Subelite, and Recreational Young Soccer Players

The purpose of the present study was to compare maximal isometric force, force-time curve characteristics, pedaling rate, vertical jump, and sprint performance among young soccer players from different competition levels. Fifty-four (54) young soccer players were divided into three groups according to competition level: the elite group (n = 18) consisted of soccer players from the national youth soccer team of Greece, the subelite group (n = 18) consisted of youth soccer players who participated in the local championship, and the recreational group (n = 18) consisted of recreational soccer players. All groups were evaluated for maximal isometric force, explosive force at 100 msec, peak force relative to body mass, rate of force development, squat and drop jump heights, 10 m sprint time, and pedaling rate. The elite group presented significantly (p < 0.05) higher maximal isometric force, vertical jump height, and pedaling rate, and lower 10 m sprint time in comparison with the subelite and recreational groups. No significant differences were observed in strength and speed characteristics between the subelite and recreational young soccer players. The findings of the present study suggest that the elite young soccer players can be distinguished from subelite and recreational young soccer players in strength and speed characteristics. These strength and speed measures can be used for strength and speed diagnosis, and for designing and evaluating training programs.

The effect of high vs. low carbohydrate diets on distances covered in soccer.

Abstract Souglis, AG, Chryssanthopoulos, CI, Travlos, AK, Zorzou, AE, Gissis, IT, Papadopoulos, CN, and Sotiropoulos, AA. The effect of high vs. low carbohydrate diets on distances covered in soccer. J Strength Cond Res 27(8): 2235–2247, 2013—The purpose of this study was to compare the distances covered during a 11-a-side soccer match after players had consumed either a high carbohydrate (CHO) or a low CHO diet. Twenty-two male professional soccer players formed 2 teams (A and B), of similar age, body characteristics, and training experience. The 2 teams played against each other twice with a week interval between. For 3.5 days before the first match, the players of team A followed a high CHO diet that provided 8 g CHO per kg body mass (BM) (HC), whereas team B players followed a low CHO diet that provided 3 g CHO per kg BM (LC) for the same time period. Before the second match the dietary treatment was reversed and followed for the same time period. Training during the study was controlled, and distances covered were measured using global positioning system technology. Every player covered a greater total distance in HC compared with the distance covered in LC (HC: 9,380 ± 98 m vs. LC: 8,077 ± 109 m; p < 0.01). All distances covered from easy jogging (7.15 km·h−1) to sprinting (24.15 km·h−1) were also higher in HC compared with LC (p < 0.01). When players followed the HC treatment, they won the match (team A vs. team B: 3-1 for the first game and 1-2 for the second game). The HC diet probably helped players to cover a greater distance compared with LC. Soccer players should avoid eating a low (3 g CHO per kg BM) CHO diet 3–4 days before an important soccer match and have a high CHO intake that provides at least 8 g CHO per kg BM.

The effect of a 4-week training regimen on body fat and aerobic capacity of professional soccer players during the transition period.

Sotiropoulos, A, Travlos, AK, Gissis, I, Souglis, AG, and Grezios, A. The effect of a 4-week training regimen on body fat and aerobic capacity of professional soccer players during the transition period. J Strength Cond Res 23(6): 1697-1703, 2009-The purpose of this study was to evaluate the changes in body fat percentage and aerobic capacity in professional soccer players, after the implementation of a specific 4-week training regimen during the transition period. Fifty-eight professional soccer players of the Greek Premier National Division were separated in experimental (n = 38) and control groups (n = 20). Body composition and maximum oxygen intake were evaluated before and after a 4-week training regimen followed during the transition period. The experimental design used for analyzing weight (kg), percent body fat (%) and &OV0312;O2 max values (ml·kg−1·min−1) was a 2 × 2 (Groups × Measures), with Groups as a between-subjects factor and Measures as a within-subjects factor. The level of significance was set at p ≤ 0.05 for all analyses. Analyses of variances showed that the experimental and the control groups achieved statistically significant (a) increases from pretest to posttest measures in body weight (0.595 kg and 1.425 kg, respectively) and percent body fat (0.25 and 0.82, respectively), and (b) decreases in &OV0312;O2max values from pretest to posttest measures (0.81 and 3.56, respectively). The findings of the study revealed that the players who followed the training regimen compared with the players that did not follow any specific training program gained less weight and body fat and exhibited lower reduction in their &OV0312;O2 max values.

Multiarticular Isokinetic High-Load Eccentric Training Induces Large Increases in Eccentric and Concentric Strength and Jumping Performance

Abstract Papadopoulos, C, Theodosiou, K, Bogdanis, GC, Gkantiraga, E, Gissis, I, Sambanis, M, Souglis, A, and Sotiropoulos, A. Multiarticular isokinetic high-load eccentric training induces large increases in eccentric and concentric strength and jumping performance. J Strength Cond Res 28(9): 2680–2688, 2014—This study investigated the effects of short-term eccentric exercise training using a custom-made isokinetic leg press device, on concentric and eccentric strength and explosiveness as well as jumping performance. Nineteen healthy males were divided into an eccentric (ECC, n = 10) and a control group (CG, n = 9). The ECC group trained twice per week for 8 weeks using an isokinetic hydraulic leg press machine against progressively increasing resistance ranging from 70 to 90% of maximal eccentric force. Jumping performance and maximal force generating capacity were measured before and after eccentric training. In the ECC group, drop jump (DJ) height and maximal power were increased by 13.6 ± 3.2% (p < 0.01) and 25.8 ± 1.2% (p < 0.01), whereas ground contact time was decreased by 17.6 ± 2.6% (p < 0.01). Changes in ankle, knee, and hip joint angles were also reduced by 33.9 ± 1.1%, 31.1 ± 1.0%, and 32.4 ± 1.6% (all p < 0.01), respectively, indicating an increase in muscle stiffness during the DJ. Maximal eccentric and concentric leg press force was increased by 64.9 ± 5.5% (p < 0.01) and 32.2 ± 8.8% (p < 0.01), respectively, and explosiveness, measured as force attained in the first 300 milliseconds, was increased by 49.1 ± 4.8% (p < 0.01) and 77.1 ± 7.7% (p < 0.01), respectively. The CG did not show any statistically significant changes in all parameters measured. The main findings of this study were that maximal concentric and eccentric force, explosiveness, and DJ performance were markedly increased after only 16 training sessions, possibly because of the high eccentric load attained during the bilateral eccentric leg press exercise performed on this custom-made device.

Muscle-contraction properties in overarm throwing movements.

On the basis of dynamic and kinematic data, this study identifies the type of muscle contraction in unloaded over-arm throwing movements. An unloaded throw or nearly unloaded throw is defined as the throw in which the external resistance is too small (e.g., the team handball, baseball, and water polo throws as well as the tennis and badminton smashes). A special arm-force–measuring apparatus was constructed to imitate an overarm throw. Forty-two subjects were placed into 3 groups: untrained subjects, weight-trained athletes, and team handball players. The measured parameters included the velocity of the initial movement, the release velocity, the velocity of the first 50 milliseconds of the concentric phase, the force value at the moment of deceleration of the initial movement, and the impulse values during the eccentric and concentric phases of the test movement. Statistically significant higher values of the above parameters (p < 0.05) were determined in that test at which the initial speed of movement was higher. Also, the correlation coefficients of the parameters of the initial phase of the throw movement were very high (p < 0.001), especially the parameters related with the movements first 50 milliseconds. The results support the thesis that the stretch–shortening cycle is the type of muscle contraction in unloaded overarm throws. Furthermore, it is possible to increase the throw velocity by increasing the velocity of the initial movement (i.e., by provoking higher inertia forces).

Changes in Homocysteine and 8-iso-PGF2a Levels in Football and Hockey Players After a Match

The aim of the present study was to evaluate the levels of homocysteine and 8-iso PGF2a in football and hockey players before and soon after a match, on the predisposition for development of atherosclerosis. We measured 8-iso-PGF2a and homocysteine in 21 football athletes aged 21.8 ± 3.7 years old and 18 hockey athletes 22.2 ± 3.3 years old, respectively. All the athletes presented significant increases in serum homocysteine levels following the match (p = 0.001 for football and p = 0.001 for hockey players) Also a statistically significant increase of 8-iso-PGF2a levels was found in hockey and football athletes following the match (p < 0.001 and p = 0.071). Our findings suggest that strenuous exercise such as a football or a hockey match causes a marked increase in serum homocysteine and 8-iso-PGF2a. Due to the fact that homocysteine and 8-iso-PGF2a are contributing to atheromatosis, it may be useful to follow a restoration exercise program that involves mild exercise and to pay special attention to folate, vitamin B6, and vitamin B12 balance during the first 24 h after the match.

Effect of Combined Sensorimotor-Resistance Training on Strength, Balance, and Jumping Performance of Soccer Players.

Abstract Manolopoulos, K, Gissis, I, Galazoulas, C, Manolopoulos, E, Patikas, D, Gollhofer, A, and Kotzamanidis, C. Effect of combined sensorimotor-resistance training on strength, balance, and jumping performance of soccer players. J Strength Cond Res 30(1): 53–59, 2016—The purpose of the study was to investigate the effects of resistance training (RT) and sensorimotor training combined with RT (SM-RT) on balance, 1 repetition maximum (RM), rate of force development (RFD), and squat jump (SJ) height. Twenty amateur soccer players were equally divided into 2 groups assigned as SM-RT group (age: 22 ± 1.7 years, body mass: 79.9 ± 6.3 kg, body height: 1.81 ± 0.06 m) and RT group (age: 21.3 ± 1.3 years, body mass: 77.4 ± 9.3 kg, body height: 1.78 ± 0.04 m). Both groups were trained over a 6-week period with 2 session units per week. SM-RT group performed sensorimotor training (balance on balance board) followed by a high-intensity RT at 8–5RM leg press. The RT group performed the resistance program only. Both groups showed significantly increased 1RM leg press strength, RFD, SJ height, and balance abilities (p ⩽ 0.05), whereas no significant between-group differences were observed in any of the outcome variables (p > 0.05). It was concluded that SM-RT was not superior compared with RT for both balance and strength enhancement. These findings have implications in time management during training for soccer players.

EVALUATION OF FORCE AND VERTICAL JUMP PERFORMANCE IN YOUNG SWIMMERS WITH DIFFERENT FORCE-TIME CURVE CHARACTERISTICS

The purpose of the present study was to examine the maximum isometric force, force produced in initial 100 ms, and vertical jump performance in swimmers with different force-time curve characteristics, such as the index of rate of force development (IRFD), the index of relative force (IRelF), and the index of reactive force (IReaF). Our results showed that swimmers with high IRFD, IRelF and IReaF values presented higher maximum isometric force, force produced in initial 100 ms, and drop jump height. Thus, the ability to develop high levels of maximum isometric force and vertical jump performance depends on force-time curve characteristics. (Biol.Sport 26:301-307, 2009)

Combined visual and dribbling performance in young soccer players of different expertise

ABSTRACT We aimed to evaluate dribbling performance in terms of technique and visual skills assessment of both young experienced (EX, n = 24) and novice (NO, n = 24) soccer players. Both groups performed two dribbling tests with four levels of difficulty in visual signals (A1–A4 and B1–B4; B – half distance of A; 1 – no visual signal; 4 – signal with the shorter flashing time). All players performed slower when visual signals were added to the testing process (~2.5 s; p < 0.01). EX completed all tests faster than NO (~3 s, p < 0.01). The average number of visual mistakes was significantly lower for EX than NO in all tests (p < 0.01). These results demonstrated the importance of evaluating dribbling along with visual stimuli in young soccer EX and NO players.

Playing Position: Anthropometric and Fitness Demands in Youth Soccer

Abstract The aim of this study was to examine the anthropometric and fitness characteristics of soccer players with different positional role. Although, players’ skills are not equally distributed in each position, at elite soccer they have to perform each skill at a sufficient level. However, coaches expertise those from an early age in specific positions without giving them an holistic individualized training. In the study participated 312 Greek players aged 6 to 17 (M= 11.89; SD= 2.33) of 5 age groups (group U7-U8; group U9-U10; group U11-U12; group U13-U14; group U15-U16; group U17). Anthropometric (height, weight, body mass index and body fat) and fitness characteristics (flexibility, vertical jump, running speed, agility and VO2max) of participants were measured. The study showed that goalkeepers and central defenders tend to perform worse than players of the other positional groups in most of their fitness characteristics for almost all the age groups. Furthermore, many tendencies were observed in anthropometric and fitness characteristics between players with different positional roles. This study provides suggestions to coaches regarding their practice of positioning players according to their anthropometric and fitness characteristics for a short term success.