Eduardo Mendonça Pimenta

Angiotensin-converting enzyme (ACE-I/D) polymorphism frequency in Brazilian soccer players.

This study aimed to analyze the angiotensin-converting enzyme (ACE-I/D) allelic and genotypic frequencies in Brazilian soccer players of different ages. The study group comprised 353 players from first-division clubs in the under (U)-14, U-15, U-17, U-20, and professional categories. The allelic and genotypic frequencies did not differ significantly in any of the categories between the group of players and the control group. This was the first study of ACE-I/D polymorphism in Brazilian soccer players.

Repeated-sprint ability determined in game in elite male Brazilian football players

ABSTRACT Purpose: To analyse if the ability of elite Brazilian football athletes to perform repeated sprints, evaluated in real game situations, correlates with their previously determined VO2max. Methods: We analysed data from 10 male elite Brazilian football athletes, who had their movements monitored in the field through GPS devices, during 17 matches of official championships. For analysis of athletes’ movements in the field, we considered a block of repeated sprints (BRS), activities characterised by at least 3 sprints with velocity ≥20 km/h separated by a maximum of 21 s between each sprint. Results: There was no correlation between the ability to perform BRS in real game situations and the previously determined VO2max of athletes (r = 0.5828; p = 0.0770). On the other side, there was a positive correlation between the performance of blocks of repeated sprints and the number of actions within the blocks (r = 0.6712; p = 0.0336), and a negative correlation between the performance of blocks of repeated sprints and the recovery time between one block and another (r = –0.9191; p = 0.0002). Conclusions: Repeated-sprint ability determined in the game in elite male Brazilian football players is not correlated with VO2max.

Validity of inner canthus temperature recorded by infrared thermography as a non-invasive surrogate measure for core temperature at rest, during exercise and recovery

Abstract Research into obtaining a fast, valid, reliable and non-invasive measure of core temperature is of interest in many disciplinary fields. Occupational and sports medicine research has attempted to determine a non-invasive proxy for core temperature particularly when access to participants is limited and thermal safety is of a concern due to protective encapsulating clothing, hot ambient environments and/or high endogenous heat production during athletic competition. This investigation aimed to determine the validity of inner canthus of the eye temperature (T EC) as an alternate non-invasive measure of intestinal core temperature (T C) during rest, exercise and post-exercise conditions. Twelve physically active males rested for 30min prior to exercise, performed 60min of aerobic exercise at 60% V̇O2max and passively recovered a further 60min post-exercise. T EC and T C were measured at 5min intervals during each condition. Mean differences between T EC and T C were 0.61°C during pre-exercise, −1.78°C during exercise and −1.00°C during post-exercise. The reliability between the methods was low in the pre-exercise (ICC=0.49 [−0.09 to 0.82]), exercise (ICC=−0.14 [−0.65 to 0.44]) and post-exercise (ICC=−0.25 [−0.70 to 0.35]) conditions. In conclusion, poor agreement was observed between the T EC values measured through IRT and T C measured through a gastrointestinal telemetry pill. Therefore, T EC is not a valid substitute measurement to gastrointestinal telemetry pill in sports and exercise science settings.

ANALYSIS OF CREATINE KINASE AND ALPHA-ACTIN CONCENTRATIONS IN SOCCER PRE-SEASON DOI: http://dx.doi.org/10.18511/0103-1716/rbcm.v23n4p5-14

Purpose: The purpose of the present study was to assess muscle overload through changes in creatine kinase (CK) activity and serum concentration of α-actin in soccer players in response of two months of pre-season physical training. Basic procedures: Ten professional athletes (26 ± 6 years of age) undergoing arduous training were evaluated. Serum CK activity and α-actin serum concentration were determined at the beginning and end of two months of pre-season training. Effort intensity was determined throughout the training sessions by monitoring heart rate (HR). Serum CK activity was determined using the colorimetric method. Plasma α-actin concentration was evaluated using ELISA and confirmed using the Western Blot method. Main Findings: Serum CK activity and α-actin concentration were higher in the post-training period in comparison to the pre-training period (CK: PRE 65.5 ± 4.2 U/L, POST 435.7 ± 70.0 U/L, p=0.0004; α-actin by Western Blot: PRE 42.9 ± 21.6 μg/mL, POST 68.1 ± 19.1 μg/mL, p=0.0004; by ELISA: PRE 70.63 ± 10.4 μg/mL, POST 101.80 ± 17.3 μg/mL, p=0.0125). Conclusions: The significant increases in α-actin concentration and in CK activity of soccer players over the two-month pre-season indicated that an elevated training overload was imposed upon the athletes.

IMPACTO DO NÍVEL COMPETITIVO E DA FAIXA ETÁRIA SOBRE FORÇA E ASSIMETRIA DE FUTEBOLISTAS JOVENS

Rev Bras Med Esporte – Vol. 24, No 5 – Set/Out, 2018 ABSTRACT Introduction: Muscular strength is an essential capacity for soccer players; however, the profile of this capacity has not yet been clearly established in young players. Objective: To compare muscular strength performance in the countermovement jump (CMJ) task and the presence of lower limb asymmetry among soccer athletes of the under 15 (U15), under 17 (U17) and under 20 (U20) categories, and between two teams of different competitive levels. Methods: One hundred and fifty one young soccer players of three different categories (U15, U17 and U20) from two teams in the Brazilian first and second divisions performed six vertical jumps in a system of two force plates. Ground reaction force (GRF) was used to calculate jump height and to obtain the variables Peak force (FMAX), Impulse (I) and Peak power (PMAX) with regard to body mass and the respective asymmetry values. Results: No differences were found in the performance and asymmetry variable between the categories (Jump height: p=0.23; FMAX: p=0.15; I: p=0.11; PMAX: p=0.32; FMAX asymmetry: p=0.21; I asymmetry: p=0.58; PMAX asymmetry: p=0.58). The first division club had higher muscle strength and asymmetry values than the second division club (Jump height: p<0.01; I: p<0.01; PMAX: p<0.01; FMAX asymmetry: p<0.01; I asymmetry: p<0.01; PMAX asymmetry: p<0.01), except for FMAX (p=0.63). No variable had an interaction effect (club x category). Conclusion: As categories progress, jump height, relative I, PMAX and FMAX values and their respective asymmetries are stable. The asymmetry and strength performance of the first division club were higher than that of the second division club, except for FMAX, indicating that the competitive level may influence strength performance and the development of asymmetry. Level of Evidence II; Diagnostic study – Investigating a diagnostic test.

Effect of a professional soccer match in skin temperature of the lower limbs: a case study

The purpose of this study is to analyze the relationship between lower limbs skin temperature (Tsk) recorded by infrared thermography and creatine kinase (CK) response following an official soccer game. A professional soccer player, from the first division Brazilian League, defender, 27 years and 183 cm of height was analyzed. Measures of Tsk with a thermal camera and blood CK concentrations were obtained 24 hr before (24H-PRE), 24 (24H-POST) and 48 hr (48H-POST) after an official match. The results showed that CK values were 193 U/L 24 hr before, rising to 1,083 U/L 24 hr after the game and 414 U/L 48 hr after the game. Anterior thigh Tsk was 31.5°C, 33.8°C, and 31.8°C in the moments 24H-PRE, 24H-POST, and 48H-POST, respectively. Similarly, anterior leg presented temperature of 31.2°C, 33.3°C, and 31.5°C at the same moments. Qualitative analysis of the thermograms showed that whole lower limbs are much warmer 24 hr after the match and certain areas as the right anterior thigh, the left anterior leg, both anterior ankles, and both posterior thighs have not fully recovered their initial Tsk 48 hr after the match. The results of this study indicate that participation in a professional soccer match can lead to significant increases in Tsk values measured by IRT 24 hr after the match. Considering this variable as an indicator of muscular damage, it could help in the process of training control, being part of an injury prevention program in professional soccer clubs.