How many trials are enough? Familiarization requirements in the Loughborough Soccer Passing Test

The Loughborough Soccer Passing Test (LSPT) has proven to be a valid and reliable method for assessing soccer skill performance. However, there are various preparation protocols that exist for the LSPT. The aim of this study is to determine how many trials are required to gather reliable data during LSPT familiarisation. 81 subelite male youths (12.70 ± 2.67 years; 158.32 ± 17.21 cm; 49.01 ± 14.19 kg) and 17 professional female soccer players (21.47 ± 2.37 years; 164.70 ± 5.00 cm; 57.11 ± 4.27 kg) participated in the study. Following a brief explanation, the participants underwent five repetitions of the LSPT, after which differences between trials were analysed using mixed ANOVA for original time, penalty time, and performance time of LSPT. Adjusted residual values and the Smallest Worthwhile Change (SWC) approach were employed to assess the distributions across repetitions and the practical significance of the observed differences. Mixed-repeated measures ANOVA showed that Trial 1 significantly underperformed relative to the subsequent four trials across all LSPT values (p < .05). There were no statistical differences observed within other trials. Considerable improvement was noted solely between the first trials and subsequent attempts; exceeding the smallest worthwhile change (SWC) thresholds of 1.38 s, 2.29 s, and 3.36 s for original time, penalty time, and total performance time, respectively. Performance time enhanced by 5% between first two trials, however strength of acquisitions remain inconsistent and negligible subsequent trials. A single trial primarily diminishes the learning effect in LSPT preparation, especially in young sub-elite athletes and professional female athletes. In particular, in situations where samples are large or testing time is limited, implementing a single familiarisation trial seems a practical and efficient option. At the same time, given the higher variability of penalty time, specialists can consider adapting the number of trials depending on the testing objectives. This finding has applicative value for coaches, physical trainers and researchers, as it allows them to reduce the time and resources required for the testing protocol without compromising the validity and reproducibility of the results.