Latest research in football week 48

#1. Modeling developmental changes in functional capacities and soccer-specific skills in male players aged 11-17 years.

Authors: Valente-Dos-Santos J, Coelho-E-Silva MJ, Simões F, Figueiredo AJ, Leite N, Elferink-Gemser MT, Malina RM, Sherar L.
Reference: Pediatr Exerc Sci. 2012 Nov;24(4):603-21.
Summary: The study evaluated the contributions of age, growth, skeletal maturation, playing position and training to longitudinal changes in functional and skill performance in male youth soccer. The authors followed 83 players for 5 years. Composite scores for functional and skill domains were calculated via regression analysis to provide an overall estimate of performance. Scores improved by age and body mass was an additional predictor: 13.48 + 1.05 × centered on chronological age (CA)-0.01 × centered CA2-0.19 × fat mass (FM) + 0.004 × annual volume training-1.04 × dribbling speed; skills (defenders): 7.62 + 0.62 × centered CA-0.06 × centered CA2 + 0.04 × fat-free mass-0.03 x FM + 0.005 × annual volume training-0.19 × repeated-sprint ability + 0.02 × aerobic endurance. Skeletal maturity status was a significant predictor of functional capacities and playing position of skill performance.

#2. Optimizing lifestyles for men regarded as 'hard-to-reach' through top-flight football/soccer clubs.

Authors: Zwolinsky S, McKenna J, Pringle A, Daly-Smith A, Robertson S, White A.
Reference: Health Educ Res. 2012 Nov 27. [Epub ahead of print]
Summary: The study assessed the effect of a 12-week behavioral intervention delivered in and by English Premier League football/soccer clubs, and its influence on lifestyle behaviors, in 138 men aged 18 years or older typically regarded as hard-to-reach. Authors used self-reported data from the players on optimal lifestyle behaviors (OLBs) (physical activity, diet, smoking and alcohol consumption) at pre- and post-intervention. After 12-week behavioral changed in part of the men involved in the study and therefore it is possible to reach and engage a proportion of at risk men. The authors conclusion was that the intervention helped to stabilize and improve several of the most important lifestyle behaviors that impact mortality and morbidity.

#3. Evaluation of heart rate recovery in relation to playing position in professional soccer players.

Authors: Bonaiuto M, Di Mauro D, Speciale F, Pagano F, Buda D, Vita G, Magaudda L, Trimarchi F.
Reference: J Sports Med Phys Fitness. 2012 Dec;52(6):583-8.
Summary: The purpose of the study was the evaluation of the autonomic cardiac function in professional soccer players by heart rate recovery (HRR) measurement after 1' or 2' of active recovery (HRR1 or HRR2, respectively) from an exercise stress test. Professional soccer players (N=92) performed an cycle ergometer exercise test followed by an active recovery phase. The study showed better autonomic function in roles with alternate aerobic-anaerobic activity compared to other roles (such as goalkeeper) and confirms the positive action of intense aerobic-anaerobic physical activity on cardiovascular autonomic system adjustment.

#4. Designing small-sided games for training tactical aspects in soccer: Extrapolating pitch sizes from full-size professional matches.

Authors: Fradua L, Zubillaga A, Caro O, Iván Fernández-García A, Ruiz-Ruiz C, Tenga A.
Reference: J Sports Sci. 2012 Nov 28. [Epub ahead of print]
Summary: The purpose of the study was to examine the 1) individual playing area, 2) length and width of the rectangle encompassing the individual playing area and 3) distance between the goalkeepers and their nearest team-mates during professional soccer matches and compare these to previously reported pitch sizes for small-sided games (SSGs). The authors collected data time motion analysis data from four Spanish La Liga matches of the 2002-03 season.  The pitch sizes obtained from real matches were smaller and different from those used previously for SSGs and the current pitch sizes show significant  effect of ball location in all variables examined, meaning that the overall individual playing area varied significantly across six different zones of the pitch. Based on these results the authors gave recommendations to design SSG with a more valid representation of the tactical conditions experienced in full-size matches. The pitch sizes with individual playing areas should range from 65 m2 to 110 m2 and length to width ratio of 1:1 and 1:1.3.

#5. Match Performance Comparison in Top English Soccer Leagues

Authors: Di Salvo V, Pigozzi F, González-Haro C, Laughlin MS, De Witt JK.
Reference: Int J Sports Med. 2012 Nov 26. [Epub ahead of print]
Summary: This study compared motions of soccer players in the English Premier (1st) and Championship (2nd) League and compiled 26 449 observations from players during 4 seasons (2006-2010) using Prozone® System and categorized by speed intensity. Number of actions, total distance and the mean distance covered at each speed intensity were measured. While there were significant differences in many variables, the authors suggested that the differences were negligible in practical terms, meaning the match-related activities do not explain the general superiority of Premiership players over Championship players in England.

#6. Differences in soccer players' dynamic balance across levels of competition

Authors: Butler RJ, Southers C, Gorman PP, Kiesel KB, Plisky PJ.
Reference: J Athl Train. 2012;47(6):616-20. doi: 10.4085/1062-6050-47.5.14.
Summary: The study investigated the differences on the Lower Quarter Y-Balance Test in male high school, collegiate, and professional soccer players. The high-school players had had a greater anterior reach distance than the other 2 groups, but also less reach distance in the posteromedial and posterolateral directions than the other groups. The authors suggested that dynamic balance performance varied with competition level, which may indicate that athletes' movement strategies may be different depending on the competition level and that normative values may need to be established for each competition level.

#7. Strength and jump biomechanics of elite and recreational female youth soccer players

Authors: Chrisman SP, O'Kane JW, Polissar NL, Tencer AF, Mack CD, Levy MR, Schiff MA.
Reference: J Athl Train. 2012;47(6):609-15. doi: 10.4085/1062-6050-47.6.01.
Summary: The study examined the injury risk factors of strength and jump biomechanics by soccer level in female youth athletes and determined whether research recommendations based on elite youth athletes could be generalized to recreational players. Ninety-two female soccer players aged 11 to 14 years were recruited and completed a questionnaire about demographics, history of previous injury, and soccer experience. Physical therapists used dynamometry to measure hip strength (abduction, adduction, extension, flexion) and knee strength (flexion, extension) and Sportsmetrics to measure vertical jump height and jump biomechanics. Linear regression analysis was used to adjust for age and mass. The results were that female elite youth players had similar lower extremity strength and jump biomechanics compared to recreational players. This suggests that recommendations generated from research with elite youth soccer players could be generalized to recreational players.

#8. Effects of a soccer season on anthropometric characteristics and physical fitness in elite young soccer players.

Authors: Hammami MA, Ben Abderrahmane A, Nebigh A, Le Moal E, Ben Ounis O, Tabka Z, Zouhal H.
Reference:  J Sports Sci. 2012 Nov 27. [Epub ahead of print]
Summary: The purpose was to evaluate the effect of a soccer-training season on the anthropometric and performance characteristics of elite youth soccer players. The authors compared 24 soccer players after a competitive season vs. 26 non-athletic controls and measured anthropometry, aerobic (Yo-Yo Intermittent Recovery test level 1) and anaerobic (counter-movement-jump (CMJ), squat-jump (SqJ), five-jump-test (5JT), and speed (5m, 10 m, 30 m)) twice during 8 months of the competitive season. The soccer players had better physical fitness test scores at both testing occasions and even improved during the training season.

#9. Half-Time and High-Speed Running in the Second Half of Soccer

Authors: Mugglestone C, Morris JG, Saunders B, Sunderland C.
Reference: Int J Sports Med. 2012 Nov 23. [Epub ahead of print]
Summary: This study investigated if the quantity of high-speed running (>15 km/h) completed in the first 15 min of competitive football matches differed from that completed in the corresponding 15 min of the second half. Twenty semi-professional soccer players were used and fifty soccer matches using Global Positioning Satellite technology. There was no differences the first 15 min of each half for the distance completed at high-speed (>15 km/h) or sprinting (>21 km/h), or in the number of sprints undertaken. However, the total distance covered and the average speed was lower in the first 15 minutes in second half compared to the first half. As a result, there is no difference between the amount of high-speed running and sprinting completed by semi-professional soccer players when the first 15 min of the first and second half of competitive matches were compared.