Volume 27 (2011): Issue 2011 (March 2011)

The take-off is often considered the most significant and difficult phase of a ski jump. Thus, the purpose of this study was to compare three groups of ski jumpers representing different skill levels during the execution of the take-off and start of the early flight phase in ski jumping. A total of 30 athletes, recruited from competitors performing ski jumps on an HS-134 m jumping hill, were categorized into three groups based on jump-length execution. Two-dimensional (2-D) kinematic data were collected from the lower extremities, trunk, and skis of the ski jumpers. Findings indicated that the ski jumpers with shorter jump length demonstrated significantly smaller in-run velocity (p < .05), while the elite and mediocre level ski jumpers exhibited a significantly faster shift of the thigh at the transition from take-off into the early flight of the jump (p < .05) than did the low-level ski jumpers. In addition, the centre of body mass (CoM) of the elite group shifted significantly more forward over the skis (p < .01) than did that of the other two groups. Finally, interindividual differences existed among ski jumpers at similar performance levels. The largest coefficients of variation (CVs) were found for the position changes of the trunk and shank behind the jumping hill edge.

This study defined the differences in physical qualities and anthropometric characteristics among playing positions in young male handball players, and investigated the relationship between ball throwing velocity and all measured parameters.

182 young male handball players, aged 14.3yrs, with playing experience of 4.5yrs, were classified as: back players, centre backs, pivots, wing players, and goalkeepers. Body height, body mass, BMI, arm span, hand length, standing long jump, 30m sprint, flexibility, VO_2max and throwing velocity were measured.

Significant differences were detected among individual positions for all measured variables, except for flexibility. Backs were tallest, while pivots showed the largest arm span and hand length. Wings were shortest, with the lowest weight and BMI. Backs and wings performed best in the standing long jump, 30m sprint, flexibility and VO_2max. Goalkeepers underperformed in all motor abilities. Ball velocity significantly correlated to all variables except for BMI and flexibility. Anthropometric and physical differences exist among different positions in young male handball players. These parameters influence ball velocity.

The findings suggest that a high performance level requires advanced physical qualities as well as anthropometric features for these ages, and coaches should apply specific training programs for each playing position.

The purposes of this study were threefold: to present the specific physical structure of elite water polo players by playing positions, to access its throwing velocity in different conditions (without goalkeeper, with goalkeeper and with previous displacement), and to observe the relationships between the assessed anthropometric and throwing velocity parameters. Nineteen water polo players of the Spanish National Team (nine offensive wings, five center back and five center forwards) were evaluated. The anthropometric profile (particularly the lengths, breaths, girths and skinfolds) was obtained according to the International Working Group of Kinanthropometry, and the throwing velocity was assessed in 3 × 2 maximal intensity shoots (3 min interval) from the penalty line using a radar. It was possible to observe higher values of body mass, BMI, and muscle mass of the center forwards compared to the wings, and foot length of the center backs compared with the wings, reflecting a specific physical profile for each playing position. However, no difference was found between groups regarding the breadths values. In addition, the somatotype of the wings is a balanced mesomorph, and the center backs and center forwards endo-mesomorphs. Despite center backs have higher hand grip values in comparison with wings, no differences were observed between specific playing positions in each throwing condition, as well as between conditions in each specific playing position. Moreover, observing the correlation coefficient values between anthropometric and throwing velocity variables by specific position for the three throwing conditions, a higher number of relationships was found for the center backs and center forwards rather than for the wings. When the total sample was analysed, a superior number of relationships was observed between the studied parameters in throwing with goalkeeper situation. These data reflects the dependence of the throwing skill on the anthropometric characteristics of water polo players.

Exposure of alpine skiing athletes, while training, at altitude hypoxia and low ambient temperature can modify the response of the immune system and increase reactive oxygen and nitrogen species (RONS) generation. The aim of this study was to evaluate the impact of six day training model "live low - train high" on selected indicators of immune and antioxidant-prooxidant balance of alpine skiing competitors. The study was performed in 7 men, alpine skiers, who underwent 6-day training at Kaunertal glacier (3160 m). Before departure to glacier training, and after returning to sea level participants underwent series of tests. Somatic characteristics, anaerobic exercise capacity, blood morphological parameters and concentrations of interleukin 6 (IL-6), C-reactive protein (hsCRP), thyroid stimulating hormone (TSH), thiobarbituric acid reactive substances (TBARS), total antioxidant status (TAS), total iron (Fe) and total iron binding capacity (TIBC) were assessed. High altitude training has led to a significant increase in anaerobic capacity (p<0.05) and serum concentrations of IL-6 and hsCRP (p<0.05). A negative correlation among the difference in iron (ΔFe) concentration between two study terms and the change of hsCRP levels was also found (p<0.05). Alpine training conditions led to a slight increase in immunological indices concentration in studied skiers. However, it did not cause any significant change in prooxidant-antioxidant balance, which could be related to earlier anaerobic training adaptation.

The aim of the study was to examine whether self-selected walking speed during downhill treadmill walking by older adults would result in muscle injury and changes in physiological responses during level walking. Twenty-six participants (age: 67 ± 4 yrs; height: 1.69 ± 0.09 m; body mass: 74.9 ± 13.1kg) were assigned to level (n = 11, 30 min, 0%) or downhill walking (n=15, 30 min, -10%) at a self-selected walking speed. Self-selected walking speed and exercise intensity were similar for both groups (level: 4.2±0.4 km·hr^-1, 42±6% VO₂max; downhill: 4.6±0.6 km·hr^-1, 44±15% VO₂max). After 48-hours, downhill walking had reduced maximal voluntary isometric force of the m. quadriceps femoris (-15%, P<0.001), indicative of muscle injury, but no changes were observed for walking economy, minute ventilation, heart rate and respiratory exchange ratio during level walking. For older adults, downhill walking at a selfselected walking speed causes muscle injury without any detrimental effect on walking economy. Regular downhill walking at a self-selected walking speed by older adults is an eccentric endurance activity that may have the potential to improve cardiovascular fitness and muscle strength.

Cross-Education is characterized as the improvement in strength of the contralateral homologous muscle after unilateral practice. One potential mechanism to explain this phenomenon is that a unilateral maximal voluntary contraction (MVC) induces an involuntary irradiation of the contralateral homologous muscles. The purpose of the present two studies was to determine if contralateral irradiation is a potential mechanism to explain effects of cross-education. Contralateral irradiation was measured as the EMG co-activation in the homologous unpracticed arm. In Study 1 a unilateral dynamic extension/flexion arm movement was used to activate the triceps. The results indicated that unilateral practice induced a contralateral co-activation on the unpracticed arm. The same result can be reported for an isometric contraction (Study 2). The two studies provided empirical evidence that unilateral MVC did induce an involuntary muscle co-activity on the contralateral homologous muscles with increasing practice time in one testing session.

The aim of this study was to analyze the effects of sports training on the physiological response to supra-maximal exercise during consecutive phases of the annual training cycle. The study was carried out in volleyball players at the onset of each training phase. VO₂ max was determined by an indirect method using the Ästand-Rhyming nomogram and biochemical analyses were performed before and after the Wingate test. Concentrations of lactate in capillary blood were measured and levels of glucose, insulin, visfatin, resistin, thiobarbituric acid reactive substances (TBARS) of serum and the total antioxidative status of plasma were determined using venous blood.

Most significant differences with respect to physiological and biochemical variables centered around the pre-competitive phase when compared to other phases of the annual training cycle. Blood visfatin concentration in highly trained volleyball players is reduced by supra-maximal exercise, whereas levels of resistin remain relatively constant at rest. With the exception of the competitive phase, values of the insulin resistance index fit within the reference range. Levels of lipid peroxidation products were inversely correlated with the insulin resistance index and resistin concentrations.

The physical training during the annual cycle does not affect resistin levels, but influences insulin, glucose and visfatin concentrations, along with markers of pro-oxidant/antioxidant balance in beach volleyball players.

The aims of this study were to describe kinanthropometric characteristics of elite male and female young paddlers and to compare their proportionality with Olympic paddlers. One hundred and eighty seven young elite sprint paddlers (124 males and 63 females), aged 13 and 14 years, were assessed using a battery of 31 anthropometric dimensions. Somatotypes, Phantom Z-scores and corrected girths were calculated. Comparison between the 13 and 14 year old paddlers showed that 14 year old males had greater height, body weight, sitting height, arm span and upper body lengths, breadths and girths than their 13 year old counterparts, whereas 14 year old female paddlers only differed significantly from the 13 year olds in biacromial breadth and corrected arm girth. Mean somatotypes of male paddlers were best described as balanced mesomorphs, while female paddlers were centrals. Olympic paddlers had higher proportional dimensions in upper body girths, and biacromial breadth in both genders. The data provided in this study could be used as a guideline for talent identification in sprint canoeing and kayaking.

The objective of this work was to define and determine the effectiveness of defensive actions applied in judo fighting. The study was based on recordings of final fights from Olympic Games, World Championships and World Cup (2005-2008). Actions of female and male contestants participating in total of 56 fights were analyzed (to an accuracy of 10-second-periods of time). All actions, including attacks, counter-attacks and defense without counter-attack, were recorded and their effectiveness, preparatory actions, breaks and the referees' decisions were evaluated. Altogether fights of 95 contestants were subjected to analysis. According to the author's classification of defensive actions, 12 types of defense without counter-attack were defined as follows: (1) hand block, (2) hip block, (3) maneuvering around, (4) twist onto abdomen, (5) hand and hip block, (6) hand block and maneuvering around, (7) stepping aside, (8) separation from grasp, (9) leaving the mat, (10) leg entanglement, (11) bridge, (12) return to tachi-waza (escape from ne-waza). Types of defense most often applied according to the study - hand block and twist onto abdomen - were the least effective (93% and 70% respectively). Ashi-waza and te-waza were throws most often applied as counter-attack. However, sutemi-waza throws were most effectively (50%) applied. Highly effective counter-attacks (28%) should serve as a clue for coaches and athletes at the competitive level. The rules set forth by professor Jigoro Kano (among others: "give up in order to win") may not be adequate for today's competition.

There have been well-documented increases in overweight and obese children, sedentary lifestyles, and increased prevalence of a hypokinetic disease over the past 20 years. Thus understanding the physical activity patterns of children is essential for developing effective interventions. Little evidence exists that illustrates the contribution of weekend, physical education, and non-physical education days to overall physical activity patterns of children. The purpose of the study was to examine differences in pedometer-determined physical activity patterns of fourth and fifth grade children during weekend, physical education and non-physical education days. Three hundred and sixty-three children (8-11 years old) from six Southwestern USA elementary schools participated by wearing pedometers (Yamax Digiwalker SW-200) for seven consecutive days. Children recorded their steps at arrival to school and when they woke up and went to bed on weekend days. During weekdays, the fourth and fifth grade children averaged 13,196 ± 3,334 and 11,295 ± 3,168 steps/day for boys and girls, respectively. This is compared to a weekend average of 7,660 ± 4,647steps/day (boys) and 7,317 ± 4,062 steps/day (girls). Children were significantly more active on physical education days, averaging 12,979 steps/day (14,197 ± 4,697 steps/day for boys and 12,058 ± 3,772 steps/day for girls),compared to non-physical education school days, when they accumulated 11,809 steps/day (12,788 ± 3,600 steps/day for boys and 11,047 ± 3,382 steps/day for girls). Based on the findings in this study, children and youth are more active during school days than on weekend days. Furthermore, children are more active on physical education days than non-physical education days. These findings suggest that increased physical activity programming and interventions during weekend days may be needed to increase physical activity. The expansion of school-based physical education across more school days may also serve to increase children's physical activity during the school week.

The aim of the present study was to identify performance indicators that discriminate winning teams from drawing and losing teams in the UEFA Champions League. All 288 matches played at the group stage in the 2007-2008, 2008-2009, and 2009-2010 seasons were analyzed. The game-related statistics gathered were: total shots, shots on goal, effectiveness, passes, successful passes, crosses, offsides committed and received, corners, ball possession, crosses against, fouls committed and received, corners against, yellow and red cards, venue, and quality of opposition. Data were analyzed performing a one-way ANOVA and a discriminant analysis. The results showed that winning teams had significantly higher average values that were for the following game statistics: total shots (p<0.01), shots on goal (p<0.01), effectiveness (p<0.01), passes (p<0.05), successful passes (p<0.05), and ball possession (p<0.05). Losing teams had significantly higher values in the variable yellow cards (p<0.01), and red cards (p<0.01). Discriminant analysis allowed to conclude the following: the variables that discriminate between winning, drawing and losing teams were the shots on goal, crosses, ball possession, venue and quality of opposition. Coaches and players should be aware of these different profiles in order to increase knowledge about game cognitive and motor solicitation and, therefore, to design and evaluate practices and competitions for soccer peak performance teams in a collective way.

In order to improve the influence of Physical Education within schools on the creation of a healthy lifestyle, it is essential to analyze students' opinions in regard to this subject and its teachers. The aim of this research was to establish lifestyle typologies and to find out if these are correlated with the perception of Physical Education and its teachers. The participants in this research consisted of 745 teenagers belonging to three different rural environments. In order to establish typologies related to the use of spare time, a cluster analysis was carried out. Then, the relation between lifestyle and the evaluation of Physical Education was determined by means of the Chi-square test. The results show the existence of two lifestyle typologies. The group with a healthier lifestyle is the one that rates Physical Education and its teachers more positively.

This paper presents a statistical analysis of basketball team leaders performance during a championship status tournament in team sports using the example of the 36th European Championships EuroBasket 2009. The list of player-leaders of particular national teams was developed by means of the expert method, based on the analysis of qualitative and quantitative data. Empirical data gathered were taken from the website of EuroBasket 2009 Poland (www.eurobasket2009.org) and FIBA Europe (www.fiba.com). Formal statistical methods concerning sample description were used. The comparative analysis was conducted by means of various tabular and graphic techniques. The calculations were performed in a STATISTICA spreadsheet. The applied statistical methods allowed a series of conclusions to be drawn concerning the performance of leader-players and their cooperation with other players on the court. The knowledge of particular SGCs (standard game components) realization allows those dispositions of leader-players which are especially significant in the process of cooperation in a basketball team to be improved by coaching.

This study is an examination of the relationship between competitive anxiety and coping strategies in young athletes. Sixty karatekas and 72 track and field athletes were the subjects of the study. The age of the athletes ranged between 18 and 25 years. All had been practicing their sports for 6-8 years. The research instruments employed are the Competitive State Anxiety Inventory-2 (CSAI-2) and the Coping Inventory for Stressful Situations (CISS).

Results show that martial arts athletes reported a significantly higher level of self-confidence and lower levels of cognitive and somatic anxiety compared to track and field athletes. The two groups also differed in regard to the use of coping strategies in stressful situations. For example, the karate athletes used more effective strategies such as task-oriented coping. In the next step of the study, the subjects were divided into two groups according to the level of performance (i.e. "winners" and "losers"). The "losers exhibited higher levels of anxiety, both cognitive and somatic, than "winners". They also had higher scores on less effective coping subscales, e.g. emotion-oriented and avoidance-oriented.

There is a significant interdependence between anxiety and level of performance in competitive stress situations. Future research should also consider the possible mediating role of other psychological factors, such as personality traits.

This study investigated the academic self-efficacy of physical education and sport school students. The research group consisted of 518 students. The research data was collected following the "Academic Self Efficacy Scale" principle. Results indicated that physical education and sport school students obtained high academic self efficacy scores. While no significant difference was observed with regard to gender, class level and sport branches with gender, a significant difference was observed when considering only sport branches.