Influence of the COVID-19 pandemic on changes in aerobic fitness and injury incidence in elite male soccer players.

BACKGROUND: The SARS-CoV-2 agent initiated a global pandemic. The initial response to the pandemic was severe disruption to the public and private sector including sports. The resultant was that soccer clubs had to prescribe that the players trained in isolation for a prolonged period of time in an attempt to maintain fitness. The aim of the present study was to evaluate the impact of a 10-week period of training in isolation on aerobic fitness, body composition and injury incidence on the return to preseason team-training in a group of elite, male soccer players. METHODS: Twenty-two professional soccer players (age: 25.2±4.4 years) who played for an English Championship first team participated in this study. A weekly training program was sent to each player at the start of each week. Prior to the start of the isolated training period, all players underwent a maximal aerobic speed test (MAS), and Body Mass Index data (BMI) were obtained. These measurements were repeated on the return to team training. RESULTS: There was a significant (P<0.05) increase in MAS pre-post isolated training (pre: 4.71±0.15 vs. post: 4.92±0.17 m/s), no change in BMI (pre: 24.3±1.3 vs. post: 24.1±1.1 kg/m2) and a low non-contact, soft-tissue injury incidence on the return to team training. CONCLUSIONS: The evidence from this study suggests that a more prolonged preseason schedule can enhance aerobic conditioning and mitigate the injury risk on the return to competitive match-play in elite soccer players.

The influence of a soccer season on non-contact injury and isokinetic peak torque of the quadriceps and hamstrings in professional youth soccer players.

Isokinetic strength screening is utilized in professional soccer. However, there has been little research on the interaction between seasonal changes in players' peak torque (PT) and injury incidence. Twenty-five (age 16.5±0.68 years) professional youth soccer players participated in the study. Bilateral isokinetic concentric (CON) and eccentric (ECC) testing of Quadriceps (Q) and Hamstrings (H) were conducted at three time-points across the season. Absolute CON and ECC PT were measured at 60 degree/sec and in a supine 170-degree position. Testing data was normalized to body mass. A mixed design (2 by 3) repeated measures ANOVA with injury as a co-variate was conducted to evaluate the effect of season and/or limb dominance on PT and injury incidence. With regard to the seasonal variation and injury incidence, an interaction was identified with respect to non-dominant limb (NDL) QCON (p = 0.01) and to a lesser extent the dominant limb (DL) QCON (p = 0.05). The seasonal variation of the PT of the NDL QCON was different between the injured and non-injured individuals. Non-injured individuals, QCON strength increased over the course of the season. While for the Injured players, QCON declined from pre-season to mid-season then increased but never recovered to starting pre-season values.