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 VO2 max values (ml x kg(-1) x min(-1)) was a 2 x 2 (Groups x Measures), with Groups as a between-subjects factor and Measures as a within-subjects factor. The level of significance was set at p < or = 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 VO2 max 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 VO2 max values.

The present study investigated the effects of practice composition on acquisition and transfer of the underhand volleyball serve in a standard high school physical education setting. 72 middle-school students (M age = 14.1 yr., SD = 0.7) were selected and assigned to six groups: five experimental (Random, Serial, Blocked, Constant, Specific), and one Control group all pretested. The five experimental groups received 45 acquisition trials over three class periods. Directional quantitative knowledge of results was provided to the students after each trial. After a 72-hr. retention interval, all groups performed 15 underhand volleyball serves without knowledge of results. Analyses indicated (a) better acquisition in the Specific and Constant groups relative to the Serial, Random, and Blocked groups, and (b) significantly superior transfer performance in the Specific and Random groups relative to the Serial, Blocked, Constant, and Control groups. This provides partial support for specificity of learning and contextual interference hypotheses. Practice in accord with the contextual interference hypothesis permits differentiations among varied practice schedules only during transfer.

This study was conducted to investigate the influence of fitness level and gradually increased amounts of exercise on individuals' ratings of perceived exertion (RPE). 20 men served as paid subjects. They were divided into groups of high ( > 56 ml/kg/min.) and low fitness ( < 46 ml/kg/min.) according to their maximal oxygen uptake (VO2 (max)). Participants were required to pedal on a cycle ergometer at a progressively increased workload (every 10 min.) corresponding to 40, 50, 60, 70, and 80% of individual VO2 (max) values. Heart rates, RPE, and core temperatures were recorded every 5th minute after the initiation of exercising at a specific workload. Analysis indicated that, when controlling for VO2 (max) values, elevations of heart rate and core temperature were not affected by fitness. However, highly fit individuals perceived themselves under less exertion than did the group low in fitness. Correlations showed that, taking into consideration fitness, there is a stronger relationship between RPE and heart rate and RPE and core temperature for the highly fit individuals than for the less fit.

The purpose of the study was to (a) investigate gender and age differences in physical aggression, verbal aggression, anger, and hostility, and (b) examine the discriminatory power of the Greek version of the Aggression Questionnaire (GAQ) with high school students. The sample of the study consisted of 658 high school students (321 boys and 337 girls), with an age range from 13 to 17 years (M = 15.3, SD = 1.5). The students completed the Aggression Questionnaire adapted to Greek. Regarding gender, the overall correct identification rate in the discriminant analysis showed that 73.3% of the cases were correctly classified. In addition, the results indicated that physical aggression declined with age and that, compared to boys, girls of higher grades apply more indirect forms of aggression, such as anger and hostility. The findings of the study provide important information regarding the expression of aggressive behavior during adolescence.

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.

To examine the effects of increasing amounts of exercise on attention and speed of information processing 20 paid male subjects were separated into groups of high and low fitness according to their VO2max values. The experiment involved an attentional task (Random Number Generation) that was given after every 10 min. of cycling at work-load resistances calculated as 40%, 50%, 60%, 70%, and 80% of individual VO2max values. An eight-choice reaction time-movement time task was given before and after exercise as well as after a 15-min. recovery period. Individuals were tested within 10 min. after exercise cessation (exhaustion) for concentration and within 15 min. for choice reaction time and movement time to assess whether fitness differentially interacted with these variables. Split-plot factorial analyses of variance suggested that the CNS appeared capable of maintaining performance after 50 min. of exhaustive exercise compared to values obtained at the preexercise condition. A 15-min. recovery period significantly impaired MT but relatively highly fit individuals did not appear to perform the choice RT and concentration tasks better than individuals low in fitness.

Meta-analysis was performed to evaluate the temporal locus of knowledge of results. An extensive literature review was conducted, yielding 17 published articles suitable for the meta-analyses. These studies were then separated into 2 general categories of acquisition and retention. These categories were subdivided further into KR delay interval, KR delay and motor interpolated activities, KR delay and verbal interpolated activities, post-KR interval, post-KR interval and motor interpolated activities, and post-KR interval and verbal interpolated activities. 6 of the 12 categories gave enough data for the meta-analyses. The categories which showed significant results were KR-delay, post-KR interval, and post-KR interval and verbal interpolated activities in acquisition. Although significant, effect sizes were comparatively small. The discussion of findings focused on effects of the temporal locus of KR and interpolated activities on performance and learning.

Using a self-paced procedure, the effects of unconfounded temporal locus of KR in the acquisition of a simple linear-positioning task was examined. Changes in the chronological profile of KR delivery were evaluated when participants manipulated the time course of the experiment at their own discretion. 29 participants (18 to 32 years) practiced finding an 8-in. line with no fixed starting and ending points. One-way repeated-measures analyses of variance, simple regression analyses across blocks of practice (30), and Pearson product-moment correlations between the KR-time intervals and the performance scores indicated that (a) under self-paced procedures both the KR-delay and post-KR interval decreased congruently with performance error scores, while the temporal component of the task (movement time) and the ratio between the KR-delay and the post-KR interval remained unchanged, (b) any effect on intertrial interval and interstimulus interval in motor skill acquisition should be examined in terms of the KR-delay and post-KR interval, and (c) the relationship between the performance scores and post-KR interval may be used to indicate the point at which KR is no longer required.