Abstract
CONTEXT: The logistical efficiency and flexibility of small-sided games (SSG) to develop various soccer-specific attributes simultaneously make them a staple component of contemporary training programs in youth soccer. Their high ecological validity and consequential high utilization mean that if not considerately prescribed, players may be exposed to frequent repetitive mechanical stress that may induce maladaptation in skeletally and/or load-naïve or sensitive athletes. The purpose of this clinical review is to summarize mechanical load adaptations associated with the manipulation of area per player in SSG to outline the mechanistic pathway of load-related injuries in skeletally maturing athletes and to offer practical guidelines for coaches for the preservation of athlete health. EVIDENCE ACQUISITION: A nonsystematic search of computerized databases of peer-reviewed articles in English between 2010 and the present was used, and a critical appraisal of existing literature was subsequently conducted. STUDY DESIGN: Clinical review. LEVEL OF EVIDENCE: Level 4. RESULTS: The temporary relative strength deficit and inefficiency of the musculotendinous system associated with accelerated growth increase the mechanical cost of activity. As a result, the load tolerance (ie, tolerant, naïve, or sensitive) of athletes is transiently reduced as the musculoskeletal system struggles to attenuate force absorption adequately. Repeated exposure to submaximal mechanical loads that stimulate the accumulation of "microdamage" in structural tissue may lead to aggravation and/or tissue failure at connective sites in skeletally fragile athletes. CONCLUSION: Coaches and practitioners need to individualize exposure to mechanical load for load-tolerant, naïve, and sensitive athletes during adolescence. Subtle changes to SSG prescription including modifying the area per player, inclusion of goalkeepers, constrained floaters, and management of work; rest ratios can offer practical and efficient methods to mitigate risk without derailing the development process. This, in turn, should contribute to reducing injury burden in this population and enhance developmental opportunities for young players. STRENGTH OF RECOMMENDATION: A. Recommendation based on consistent and good-quality evidence published from 2010 onwards.