Author(s): SOUGLIS, A.G.1, TRAVLOS, A.K.2, KALIARNTAS, K.3, ANDRONIKOS, G.3, APOSTOLIDIS, A.1, NOUTSOS, K.1, BOURDAS, D.I.1, GELADAS, N.D.1, BOGDANIS, G.1, Institution: UNIVERSITY OF ATHENS, Country: GREECE, Abstract-ID: 894

INTRODUCTION:
Coaches teach technical skills using practice scheduling with higher rather than lower amounts of contextual interference (CI) [1]. Learning outcomes are greater when motor skills are practiced in a random order (high CI) than blocked practice (low CI) [2]. This study explored the effects of practice scheduling (random, serial, blocked) on soccer shooting performance.
METHODS:
Forty-two male players (age: 22.7 ± 2.2 y, experience: 14.3 ± 2.6 y) were randomly assigned into 3 groups (random, serial, blocked) and undertook 216 acquisition trials over six consecutive days (36 trials/day). During the acquisition phase, the three groups performed the shots on random, serial, and blocked practice schedules with verbal directional quantitative knowledge of results (KR). The practice schedule included 3 targets (lower left/right corners, upper middle of the goal). The random and serial groups per-formed 36 trials each day to all targets. The blocked group performed 36 trials on a different target each day. Targets consisted of concentric circles with a radius of 15, 30, 45 and 60 cm from the target’s center, scoring 4 points in the center and 3, 2, 1 points towards the outer target circles and 0 when there was no-contact of the ball with the target. Testing included 24 shots (20-meters distance from the middle of the goalposts) in a serial order on two targets placed at the upper left/right corners of a standard goal, at baseline and at the transfer phase (48-hour delayed retention interval) without additional KR. Groups by time (3x8) mixed repeated measures ANOVA was used for main and interaction effects followed by Bonferroni post hoc tests.
RESULTS:
Analysis showed significance for group (p < 0.001, η2 = 0.4), time (p < 0.001, η2 = 0.8) and group by time interaction (p < 0.001, η2 = 0.8). Bonferroni pairwise comparisons for the interaction showed: (a) no between groups differences at baseline (p > 0.05), (b) at the acquisition phase, the random and serial groups improved significantly from day 1 to day 6 (p < 0.05), while the blocked group improved significantly from day 1 to day 3 (p < 0.05), and from day 4 to day 6 performance returned to baseline (p > 0.05), and (c) at the transfer phase, the random group performed significantly better than the serial and blocked groups, which also differed (1.8 ± 0.1 vs. 1.5 ± 0.1 and 1.1 ± 0.1, respectively, all p < 0.05). At the transfer phase blocked group’s performance returned to baseline (1.1 ± .08).
CONCLUSION:
These findings agree with studies estimating the ecological validity of the CI hypothesis [3] and support the predictions of CI effect, indicating better performances when practicing with an increasing CI arrangement (random practice) compared to serial or blocked schedules. To improve long-term learning in mastering technical soccer skills, coaches are encouraged to implement random scheduling in their training programs.

1. Magill & Anderson (2021), 2. Makaruk et al. (2024), 3. Travlos (2010)