Purpose. The purpose of the present study was fourfold: (i) to describe the weekly variations of acute external load measures during a professional soccer season; (ii) to analyse the variability of external load measures within weeks; (iii) to analyse the acute:chronic workload ratio of players during the process; and (iv) to analyse the differences of external load measures between playing positions. Methods. Twenty professional soccer players (age: 24.9 ± 3.5 years; body mass: 71.6 ± 18.7 kg; height: 168.8 ± 41.4 cm) from the same team competing in the First Portuguese League (Europe) voluntarily participated in this study. They were daily monitored with a Global Positioning System (GPS) and the following external load variables were extracted per session: (i) total distance; (ii) running distance; (iii) high-speed running distance; (iv) distance at maximal speed; (v) distance at high accelerations; and (vi) players' training load. The acute load and acute:chronic workload ratio were weekly calculated for each of the GPS measures. Results. Week-by-week variations ranged from-57% to +115%, depending on the playing position and the variable measured. The within-week variability revealed coefficients of variation between 48% and 55%, depending on the measure. Considering the differences in mean load between playing positions, significant differences between players were found for the majority of the variables, with the only exceptions being maximal speed and high accelerations distances. Conclusions. Great between-week variations in the acute load as well as the variability of load within weeks were found. It was observed that acute load was position-dependent.

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Introduction. A soccer player with good ball control is the one who is able to perform complex coordinated situational motor actions in a certain space and in as short time period as possible. The analysis included variations in the angle of the knee joint of the leg receiving a ball (AKLR), angle of the knee joint of the supporting leg (AKLS), angle between thighs (ABT), trunk bending angle (TBA), hip joint point height (HPH), and ball distance after controlling the ball (BDAC) between effective and ineffective passing in soccer. Material and Methods. A total of 12 university soccer players (age: 20.8 ± .83 years old, experience: 4.7 ±.78 years) voluntarily participated in the study. The players made five attempts to control the ball with the inside foot. The best attempt was analysed for each case (effective and ineffective). Results. The degrees of AKLR, AKLS, ABT, TBA and HPH were significantly greater in effective passing than those in ineffective passing; the observed effect sizes were 4.87, 2.53, 1.77, 3.98, and 3.40, respectively. BDAC was meaningfully greater at ineffective passing (effect size: 2.03). Conclusions. There were significant differences in the values of kinematic variables used to test ball control by effective and ineffective passes (p < 0.05). The research sample, in terms of the values of kinematic variables, achieved noticeable progress during the performance of ball control for effective passing, which showed its effectiveness in reducing the distance after controlling the ball.

Purpose. the present study assesses the extent to which delayed mechanical feedback affects technical and numerical long jump performance. Methods. the participants were 45 first-grade students from the Department of Physical Education of Umm Al-Qura University. they were randomly divided into 3 equal groups. the first experimental group used delayed mechanical feedback, the second experimental group applied fast visual feedback, and the control group received oral explanation and guidance of a teacher. the delayed mechanical feedback condition lasted for 6 weeks. Each week included 2 units, each lasting for 90 minutes. Results. the educational programs had a significant main effect on technical and numerical long jump performance (p < 0.05), with a large effect size, as the percentage of improvement ranged 9.95-42.32%. Also, the differences across the 3 groups were statistically significant in terms of their technical and numerical performance (p < 0.05), favouring the mechanical feedback group, except for the difference between the fast visual feedback and the teacher guidance groups. Conclusions. the delayed mechanical feedback program had a more significant positive effect on technical and numerical long jump performance than the other 2 programs.