Search

The aims of the current study were (a) to analyze the characteristics of acceleration efforts using individual relative thresholds according to the initial speed during official matches in elite young soccer players according to player position and (b) to compare the differences between absolute and relative thresholds in assessing high-intensity acceleration. Player acceleration profiles were assessed using an individual relative threshold based on their acceleration capacity at different initial speeds (standing, 6, 10.8, and 15 km⋅h-1), and the number of accelerations (>75% of the maximal acceleration) performed during soccer matches was divided into 3 categories attending to the initial speed. (S1 = 0-7km⋅h-1; S2 = 7.1-14km⋅h-1; and S3 = >14.1 km⋅h-1). Within-group analyses showed that the number of accelerations performed in each category was higher when the effort started from a static or walking position than at moderate- or high-intensity running (S1 > S2 > S3; very likely to almost certain). Between-group analyses revealed substantial differences between some playing positions according to initial speed. In S1 and S3, central defenders had the lowest number of accelerations (likely to almost certain), whereas midfielders had the greatest number of high-intensity accelerations in S1 and S2. There were also substantial differences between the other playing positions (possibly to almost certain). Regarding relative and absolute thresholds (>3 m⋅s-2), the results showed that absolute threshold overestimated the number of high-intensity accelerations compared with the individual relative threshold in S1 and underestimated the results in S2 and S3 (almost certain). The use of an individual relative threshold to measure acceleration demands allows to distinguish between the numbers of accelerations in function of the initial speed and playing positions. In addition, the absolute acceleration threshold could overestimate or underestimate the acceleration demands in young soccer players as a function of the initial speed. Then, the absolute acceleration thresholds should be taken with caution in the assessment of acceleration activities. [ABSTRACT FROM AUTHOR]

The aims of this study were (a) to assess the relationship between laboratory-measured VO2max with total distance covered in a soccer match, (b) to assess the relationship between laboratory-measured VO2max with the distance covered at a different running intensity in a soccer match, (c) to quantify different intensity running in various playing positions, and (d) to determine the differences of running performance between halves. Analyzed match running performance of the Greek elite (n = 14) soccer players using a global positioning system within the second division professional league. No correlation was found between VO2max and match running performance at any velocity. The players covered greater distances in the first half at all speed levels except walking. In the first half, they covered a greater distance than in the second half (1,533 vs. 1,297 m, p < 0.001; 879 vs. 708 m, p < 0.001; 433 vs. 359 m, p < 001; 185 vs. 152 m, p < 0.01; 81.4 vs. 65.5 m, p < 0.001) when jogging, running, high-intensity running, fast running, sprint and total, respectively. Wide players covered greater distances at fast running (p < 0.001) and sprint zone than the players who played at the axon of the field (348 vs. 297 and 186 vs. 113 m, respectively). In addition, midfielders covered a greater distance at high-intensity running zone and at fast running zone than the defenders and forwards (1,768 vs. 1,372 m, p < 0.01 and 1,768 vs. 1,361 m, p < 0.01; 686 vs. 878 m, p < 0.01 and 709 vs. 878 m, p < 0.05, respectively). The results demonstrate that match running performance and the distance covered depends on the tactical role of each player in the team. These data provide valuable information for coaches regarding the running profile of the Greek elite soccer players that could be used to design a more effective training program. [ABSTRACT FROM AUTHOR]

The article discusses research on the use of a graded shuttle run test for evaluating physiological differences between elite female basketball players in varying playing positions. Topics explored include the measurement of physiological parameters such as oxygen consumption, respiratory quotient, and pulmonary ventilation, the heart rate and maximal lactate values recorded during the intermittent fitness testing, and the factors being considered in determining basketball playing positions.