BRIEF REPORT Injuries in Youth Soccer During the Preseason Joa ˜o Brito, BSc,* Anto ´nio Rebelo, PhD,* Jose ´ M. Soares, PhD,* Andre ´ Seabra, PhD,* Peter Krustrup, PhD,† and Robert M. Malina, PhD‡§ Objective: To evaluate injuries occurring during the preseason in youth soccer players. Design: Prospective cohort study over 1 preseason. Setting: 2009-2010 preseason. Participants: Subjects were 912 youths aged 12 to 19 years. Assessment of Risk Factors: The club’s medical staff pro- spectively recorded all injuries. A reportable injury was defined as by the consensus statement on soccer injuries. Estimated injury rates per 1000 hours of exposure during the preseason period were calculated. Main Outcome Measures: Injury rates (injuries per 1000 hours of soccer exposure) during preseason practices by age group, as well as prevalence, severity, and type of injuries. Results: Total incidence was 2.5 injuries per 1000 hours of expo- sure. Incidence of match and training injuries were 6.7 and 1.8 in- juries per 1000 hours (P = 0.02), respectively. Injuries were sustained by 7.2% of players during the preseason, and 79% of the injuries involved the lower limbs, of which 23% were located to the thigh. Muscle strains and contusions were the most common injuries and external trauma the main cause. Conclusions: No age-related trend in the incidence of preseason injuries was found. During the preseason training period, athletic trainers should expect a majority of muscle strains, especially in the thigh region. Key Words: youth sports, young athletes, injury epidemiology, conditioning, adolescents (Clin J Sport Med 2011;21:259–260) INTRODUCTION Soccer is the most popular sport worldwide. Despite its attractiveness, there is a lack of empirical information on the incidence of injuries in youth soccer in southern Europe. 1 It has been suggested that injuries among youth players occur more often during the preseason than during the competitive season. 2 Nevertheless, preseason injuries in youth soccer merit further study. The purpose of this study was to prospectively evaluate injuries sustained by youth soccer players during preseason training. METHODS A random sample of 40 sub-elite youth Portuguese soccer teams from several competitive age groups participated in the prospective cohort study (U13, U15, U17, and U19; 10 teams per age group). The 40 teams included 912 male players aged 12 to 19 years. The study was approved by the Research Ethics Committee of the Faculty of Sport, University of Porto, and by each club. Each club provided written notice after receiving informed consent from the parents and players. Data were collected prospectively for 741 players (82.3%) during the 2009-2010 preseason [approximately 6 weeks from August through mid-September (39 6 8 days)]. Each team trained 3 to 4 times per week. Methodological procedures were consistent with the consensus statement on soccer injuries. 3 An injury was defined as any physical complaint occurring during practice that prevented a player from participating in training or match play for at least 1 day after the day of the onset. 3 Injury severity was classified by time loss: minimal (1-3 days), mild (4-7 days), moderate (8-28 days), and severe (.28 days). Time loss due to injury was prospectively recorded on a weekly basis by each team’s medical staff (physiotherapists in 37 teams; coaches in 3 teams) using a standardized injury report form during the preseason and during the regular season, if necessary. 3 Exposure data were collected on a team basis. Injury incidence was calculated per 1000 hours of exposure to training and matches. In addition to descriptive statistics, paired-sample t tests were used. Statistical significance criterion was 0.05. RESULTS Fifty-three injuries (match, 16; training, 37) were sustained by 7.2% of the players during the preseason. Total exposure was 23 364 hours (training, 20 847 hours; match, 2517 hours). The estimated total incidence was 2.5 injuries per 1000 hours of exposure (95% confidence interval, 1.6-3.4). Incidence during matches [6.8 (2.9-10.6) injuries/1000 hours] was significantly higher than during training [1.8 (0.9-2.7) injuries/1000 hours] Submitted for publication January 23, 2010; accepted March 14, 2011. From the *Centre of Research, Education, Innovation and Intervention in Sport, Faculty of Sport, University of Porto, Porto, Portugal; †Department of Exercise and Sport Sciences, Section of Human Physiology, University of Copenhagen, Copenhagen, Denmark; ‡Department of Kinesiology and Health Education, University of Texas at Austin, Austin, Texas; and §Department of Kinesiology, Tarleton State University, Stephenville, Texas. The authors report no conflict of interest. Corresponding Author: Joa ˜o Brito, BSc, Faculty of Sport, University of Porto, Rua Dr. Pla ´cido Costa, 91-4200.450 Porto, Portugal (jbrito@fade.up.pt). Copyright Ó 2011 by Lippincott Williams & Wilkins Clin J Sport Med  Volume 21, Number 3, May 2011 www.cjsportmed.com | 259