Abstract
The aim of this study was to investigate changes in the linear running speed (LRS) for 30 m, change of direction speed (CODS), and endurance in young elite Czech soccer players. The following tests were conducted to assess CODS and endurance: Agility 505 turning toward the dominant (A505DL) and non-dominant lower limb (A505NL); Illinois Agility Test (IAT); and intermittent test (Yo-Yo IRT1). During the soccer season, we investigated performance at the following time periods: the start (t1) and the end of the pre-season period (t2); during (t3) and at the end of the competitive period (t4). Repeated measurement analysis of variance revealed a significant effect of time period on selected fitness parameters (p < 0.05). Post hoc analysis for test A505DL revealed significant improvements of performance at t3 (2.71 ± 0.08 s) and t4 (2.72 ± 0.06 s) compared to t1 (2.81 ± 0.09 s). A505NL was significantly different between t1 (2.83 ± 0.09 s) and t2 (2.76 ± 0.09 s), t3 (2.7 ± 0.07 s) and t4 (2.71 ± 0.09 s). Performance of CODS at t1 for the IAT (18.82 ± 0.56 s) was significantly lower (p < 0.05) than any other time period (t2 = 18.52 ± 0.63 s, t3 = 17.94 ± 0.51 s, t4 = 17.89 ± 0.66 s). The power of LRS was significantly different at t3 (4.99 ± 0.15 s), and t4 (4.98 ± 0.17 s) compared to t1 (5.15 ± 0.21 s), and t2 (5.07 ± 0.14 s). For the Yo-Yo IRT1 test, we observed a significant increase in performance between t1 (625.26 ± 170.34 m), t2 (858.95 ± 210.55 m), and t3 (953.68 ± 229.88 m). These results show the impact of soccer season time period on young soccer player performance and may further serve as a basis for comparison with similar research conducted by peers. These results may aid sports practice for clinicians, conditioning coaches, soccer coaches and physiotherapeutic coaches.
Highlights
In soccer, there are demands imposed on soccer players in terms of fitness readiness requirements to produce power, explosiveness, speed, agility, balance, body stability, flexibility and an adequate level of endurance [1,2,3]
We focused on young players from the under 13 years-of-age (U13) category where we observed changes over time from pre-season preparation to the end of the competitive period
In the agility 505 test, turning toward the dominant lower limb, players achieved a significant improvement from the start of pre-season (t1 ) to performance during the competitive period (t3 ) (3.6%), and at the end of the competitive period (t4 ) (3.2%)
Summary
There are demands imposed on soccer players in terms of fitness readiness requirements to produce power, explosiveness, speed, agility, balance, body stability, flexibility and an adequate level of endurance [1,2,3]. Aerobic capacity is an important factor which, in addition to the quality of the game itself, affects the final position of the teams in the league [4,5]. Aerobic capacity has beneficial effects on parameters such as total time spent on high intensity activities during the game, number of sprints and the number of contacts with the ball during the match. Components of anaerobic capacity have the biggest impact on the final outcome of the match and are characterized by repeated short high-intensity activity. The number of these high-intensity activities during the match falls in Sports 2017, 5, 12; doi:10.3390/sports5010012 www.mdpi.com/journal/sports
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