title: Are elite soccer players being physically prepared for the next level? Physical profiling of elite soccer players: a comparison from youth to professional level
Creators: name: Millar, Kirsty
Publisher: name: University of Glasgow
Year: 2021

description: Progression to top tier soccer is not guaranteed for elite youth soccer players; in fact, there is a substantial attrition rate between youth academy and First Team level. Previous research has investigated the differing physical demands between academy age groups (Buchheit et al. 2010) and between tiers of adult professional soccer (Mohr, 2003). No previous research has combined the two and examined the physical demands between older academy squads and the First Team of an elite club, including the transitional Reserve squad (sometimes referred to as the development squad). The aim of this study was, therefore, to examine the differences in physical profiles across the 2019/20 season between top academy squads, the transitional Reserve team squad, as well as looking into the differing external demands experienced across levels of play, including the transition between the Reserve and First Team squad. The end goal was to determine whether players are being physically prepared to progress to the next level of play. It is important to note data collection across the season was not completed due to the COVID-19 pandemic. Physical profiles were determined using a battery of tests to measure: agility (adapted 505 test), speed (30 m sprint), strength (Nordic Curl), power (CMJ, SJ, HJ) and aerobic capacity (1500 m time-trial (TT)) at the start of the season (October) and mid-season (January). Demands of play, both in training and matches, were established by analysing GPS data collected by 10 Hz Catapult X4 (U16), Catapult Clearsky (U18) and Catapult EVO (Reserve and First Team) GPS devices. The testing results showed a general increase in physical capacities with age, particularly strength and power qualities across both October and January testing timepoints. In October, the U18 and Reserve squad countermovement jump results were 3.57 cm and 5.06 cm greater than the U16 group, respectively. Additionally, bilateral eccentric strength results in October showed the U18 and Reserve squad to be 86.85 N and 161.7 N stronger than the U16 group, respectively. Both of the U16 to Reserve squad differences were deemed significant (p &lt;0.05). The results highlight a greater jump between U16 and U18 level than U18 and Reserve team level, who performed similarly. This is likely due to less opportunity to develop these qualities in a strength and conditioning (S+C) program following maturation. Training and match GPS data displayed similarities in terms of total distance between academy and Reserve team squads, however, a jump in high-speed distance between training and matches was apparent, suggesting players may not be adequately prepared for match-play in training. For example, between August to October, the U18 squad covered 124.66 m over 5 m/s in training compared to 592.83 m in matches, on average. The same trend was also reported in January across the U16 squad. However, it was important to consider the effects of periodisation. Between the Reserve and First Team, the most notable difference was match congestion, as the Reserve team competed in one match per week compared to between two and three in the First Team. This resulted in an approximate 10 km greater total distance covered in an average week by the First Team. It was suggested that the Reserve squad introduce a ‘bounce game’ mid-week to “bridge the gap” between the two teams. In conclusion, several limitations hindered the validity and reliability of results, therefore, to increase the meaningfulness of results, testing protocols should be more strongly adhered to. The academy squads are on-track to reaching the physical capacities of the Reserve squad through their appropriately loaded S+C programs following maturation. The primary concern highlighted by this study is the discrepancy in match congestion as a player progresses to top tier level, suggesting that Reserve players may not be being physically prepared for First Team level, increasing injury risk, and possibly prevalence.