Latest research in football - week 15 - 2014

#1 Ventilatory response to exercise of elite soccer players
Authors: Di Paco A, Catapano GA, Vagheggini G, Mazzoleni S, Micheli ML, Ambrosino N.
Reference: Multidiscip Respir Med. 2014 Apr 2;9(1):20. doi: 10.1186/2049-6958-9-20.
Summary: The purpose of this study was to evaluate the role of ventilatory parameters in maximal exercise performance in elite soccer players. From September 2009 to December 2012, 90 elite soccer players underwent evaluation of lung function test and ergospirometry by means of an incremental symptom-limited treadmill test. Results were analyzed according to i) maximal exercise velocity performed (Hi-M: high-performers, >18.65 km/h; Lo-M: low-performers, <18.65 km/h) and ii) usual role in the team. Hi-M showed higher peak minute ventilation (V˙Epeak: 158.3 ± 19.5 vs 148.0 ± 18.54 L/min, p = 0.0203), and forced expiratory volume at first second (5.28 ± 0.50 vs 4.89 ± 0.52 liters, p < 0.001) than Lo-M, independently of playing role. Moreover, a significant correlation between peak oxygen uptake and V˙E (r = 0.57, p < 0.001) was found. Ventilatory response plays a role in the assessment of exercise capacity in elite soccer players.


#2 Allopurinol prevents cardiac and skeletal muscle damage in professional soccer players
Authors: Sanchis-Gomar F1, Pareja-Galeano H, Gomez-Cabrera MC, Candel J, Lippi G, Salvagno GL, Mann GE, Viña J.
Reference: Scand J Med Sci Sports. 2014 Apr 1. doi: 10.1111/sms.12213. [Epub ahead of print]
Summary: Xanthine oxidase (XO), a free radical-generating enzyme, is involved in tissue damage produced during exhaustive exercise. Our aim was to test whether allopurinol, a powerful inhibitor of XO, may be effective in preventing exercise-induced tissue damage in soccer players. Twelve soccer players were randomized into two experimental groups. One received allopurinol, before a match of the premier Spanish Football League, and the other placebo. Allopurinol prevented the exercise-induced increase in all the markers of skeletal muscle damage analyzed: creatine kinase, lactate dehydrogenase, aspartate aminotransferase, and myoglobin. Creatine kinase-MB isoenzyme and highly sensitive troponin T, specific biomarkers of myocardial injury, increased significantly in the placebo but not in the allopurinol-treated group after the football match. We also found that the exercise-induced lipid peroxidation, as reflected by malondialdehyde measurements, was prevented after allopurinol administration. However, inhibition of XO did not prevent the increment in the activity of alanine aminotransferase found after the match. No changes in the serum gamma glutamyltransferase activity was found after the match on either the placebo and the allopurinol groups. These two enzymes were determined as biomarkers of liver injury. Allopurinol represents an effective and inexpensive pharmacological agent to prevent tissue damage in soccer players.


#3 Effects of a Carbohydrate-Electrolyte Drink on Specific Soccer Tests and Performance
Authors: Ostojic SM, Mazic S.
Reference: J Sports Sci Med. 2002 Jun 20;1(2):47-53. eCollection 2002.
Summary: The aim of this study was to examine the effects of a carbohydrate-electrolyte drink on specific soccer tests and performance. Twenty-two professional male soccer players volunteered to participate in the study. The players were allocated to two assigned trials ingesting carbohydrate-electrolyte drink (7% carbohydrates, sodium 24 mmol.l-1, chloride 12 mmol.l-1, potassium 3 mmol.l-1) or placebo during a 90 min on-field soccer match. The trials were matched for subjects' age, weight, height and maximal oxygen uptake. Immediately after the match, players completed four soccer-specific skill tests. Blood glucose concentration [mean (SD)] was higher at the end of the match-play in the carbohydrate-electrolyte trial than in the placebo trial (4.4 (0.3) vs. 4.0 (0.3) mmol.l-1, P < 0.05). Subjects in the carbohydrate-electrolyte trial finished the specific dribble test faster in comparison with subjects in the placebo trial (12.9 (0.4) vs. 13.6 (0.5) s, P < 0.05). Ratings of the precision test were higher in the carbohydrate-electrolyte trial as compared to the placebo trial (17.2 (4.8) vs. 15.1 (5.2), P < 0.05) but there were no differences in coordination test and power test results between trials. The main finding of the present study indicates that supplementation with carbohydrate-electrolyte solution improved soccer-specific skill performance and recovery after an on-field soccer match compared with ingestion of placebo. This suggests that soccer players should consume carbohydrate-electrolyte fluid throughout a game to help prevent deterioration in specific skill performance.


#4 Influence of sports injury changes in mood and precompetitive anxiety in soccer players
Authors: Olmedilla, A.; Ortega, E.; Gómez, J. M.
Reference: Cuadernos de Psicología del Deporte 2014 Vol. 14 No. 1 pp. 55-61
Summary: The study of the relationship between injury and psychological aspects of sport has increased in recent years, although many questions remain unanswered. The aim of this study was to analyze the incidence of injury on changes in mood and precompetitive anxiety of the players. The sample consisted of 13 players for men's soccer teams who were injured during the course of the 2011-2012 season. The age range was 21 to 29 years, with a mean of 24.58 years (SD=3.42). The injuries to players were from the point of view of the severity of moderate character. They conducted a longitudinal design, the data were taken during a full season of competition, evaluating each official competition match competitive anxiety, mood, and injuries in training and match recorded. The results indicate that the players before the injury manifested higher levels of stress and self-confidence, and after suffering an injury manifested higher levels of depression, cognitive anxiety and somatic anxiety. Results are discussed and practical applications derived from them are proposed.


#5 Rate of perceived exertion as a useful tool during a football competition in young soccer players
Authors: Calahorro Cañada, F.; Torres-Luque, G.; Lara-Sánchez, A. J.
Reference: Cuadernos de Psicología del Deporte 2014 Vol. 14 No. 1 pp. 75-81
Summary: The purpose of this study is to analyze an official football competition between young soccer players and test the effectiveness of the Rate of Perceived Exertion (RPE) to measure the intensity during the match. 22 players were selected (17,43±0,84 years, 71,71±5,71 kg, 178,65±4,10 cm) from of a youth football team from the first Spanish division. An official football competition was assessed, carrying out 6 measurements (first and second halves, halftime and fulltime) from three variables: RPE (6-20 items); Heart Rate (FC) and (Blood Lactate Concentration) ([Lac]). The results show an average values of RPE of 14,13; a FC of 158,65 lat.min-1; and a [Lac] de 3,75 mmol.l-1. It has been found in general, a similar behavior between the RPE-FC and RPE-[Lac]. RPE might be a good indicator to register the intensity for young soccer players, being an easy and effective tool for coaches to use it while controlling the internal load that involves the official competition