Quantifying exposure and intra-individual reliability of high-speed and sprint running during sided-games training in soccer players: a systematic review and meta-analysis
Authors: Dello Iacono Antonio , McLaren Shaun , Macpherson Tom , Beato Marco , Weston Matthew , Unnithan Vishanath , Shushan Tzlil 
Published: April 2022

Background Sided-games (i.e., small- [SSG], medium- [MSG], large-sided [LSG]) involve tactical, technical, physical and psychological elements and are commonly implemented in soccer training. Although soccer sided-games research is plentiful, a meta-analytical synthesis of external load exposure during sided-games is lacking. Objective The objective of this systematic review and meta-analysis was to: 1) synthesise the evidence on high-speed and sprint running exposure induced by sided-games in adult soccer players, 2) establish pooled estimates and intra-individual reliability for high-speed and sprint running exposure, and 3) explore the moderating effects of game format and playing constraints.Methods A literature search was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses 2020 guidelines. Four databases (PubMed/MEDLINE, Scopus, SPORTDiscus, Web of Science) were systematically searched up to 25 January 2022. Eligibility criteria were adult soccer players (population); training programmes incorporating sided-games (intervention); game manipulations including number of players, pitch dimension, game orientation (comparator); and high-, very high-speed and sprint relative (m∙min-1) running distances and associated intra-individual reliability (outcome). Eligible study risk of bias was evaluated using RoBANS. Pooled estimates for high-speed and sprint running exposure, and their intra-individual reliability, along with the moderating effect of tracking device running velocity thresholds, pitch dimension (i.e., area per player), and game orientation (i.e., score or possession), were determined via multilevel mixed effects meta-analysis. Estimate uncertainty is presented as 95% compatibility intervals (CI) with the likely range of relative distances in similar future studies determined via 95% prediction intervals (PI).Results A total of 104 and 7 studies met our eligibility criteria for the main and reliability analyses, respectively. The range of relative distances covered across SSG, MSG and LSG was 14.8 m∙min-1 (95% CI: 12.3 to 17.4) to 17.2 m∙min-1 (95% CI: 13.5 to 20.8) for high-speed running, 2.7 m∙min-1 (95% CI: 1.8 to 3.5) to 3.6 m∙min-1 (95% CI: 2.3 to 4.8) for very high-speed running, and 0.2 m∙min-1 (95% CI: 0.1 to 0.4) to 0.7 m∙min-1 (95% CI: 0.5 to 0.9) for sprinting. Across different game formats, 95% PI’s showed future exposure for high-speed, very high-speed running, and sprinting to be from 0 m∙min-1 to 46.5 m∙min-1, 0 m∙min-1 to 14.2 m∙min-1, and 0 m∙min-1 to 2.6 m∙min-1, respectively. High-speed, very high-speed running, and sprinting showed poor reliability with a pooled coefficient of variation of 22.8% with distances being moderated by device speed thresholds, pitch dimension and game orientation.Conclusions This study is the first to provide a detailed synthesis of exposure and intra-individual reliability of high-speed and sprint running during soccer sided-games. Our estimates, along with the moderating influence of common programming variables such as velocity thresholds, area per player and game orientation should be considered for informed planning of SSG, MSG and LSG soccer training.