The alteration of oral microbiota before and after training in swimmers.

We aimed to analyze the effect of acute exercise on oral microbiota in regularly trained swimmers. As environmental factors may affect the oral microbiota; we also aimed to analyze the short-duration effect of swimming training on the oral bacteria relative difference in swimmers. Saliva samples of 20 swimmers both before and after the training were used for the oral microbiota metagenesis. The next-generation sequencing method targeting 16S rDNA gene fragments was used for genotyping. The Wilcoxon signed-rank test was used for the statistical evaluation of the taxons. The alfa diversity comparisons were assessed with the One-Way ANOVA, and the Kruskal-Wallis test was used to determine bacterial diversity. Decayed- Missed- Filled total (DMF-T) scores were the indicators of oral hygiene. A comparison of the before and after exercise microbiota of the swimmers gave rise to a statistically significant difference for Firmicutes (p=0.014) and Bacteroidetes (p=0.007) phylum; Clostridia (p=0.006) and Bacilli (p=0.048) classes; Clostridiales (p=0.004), Entomoplasmatales (p=0.009) and Bacillales (p=0.006) for ordo; Lachnospiraceae (p=0.001) family and Stenotrophomonas (p=0.013) genus. Although there were some differences within the other taxa of the bacteria, all were statistically insignificant. Streptococcus, Pseudomonas and Rothia mucilaginosa showed a correlation with the DMF-T values in swimmers. This study was the first in Turkish swimmers to investigate the relative abundance of oral microbiota. We showed that exercise within the pool water changed the oral bacteria's relative abundance. To confirm our results and clarify the effect of pool water on oral bacteria relative abundance, more studies on dietary intake should be carried out.

The Determination Of The Relationship Between Vo2max And The Angiotensin-Converting Enzyme Gene (ACE) rs1799752 Polymorphisms In The Turkish National Ice Hockey Sports Team.

In the present study, the effect of ACE rs1799752 polymorphism on maximal oxygen consumption (VO2max) in ice hockey players was analyzed. For this reason, 21 male National Ice Hockey players, aged between 18-25, were recruited for the study. The conventional polymerase chain reaction (PCR) was used on the genotype rs1799752 polymorphism. The VO2max values were calculated by using the 20m Shuttle Run tests. The numbers and percentages of the II, ID and DD genotypes were 9 (%43), 7 (%33), and 5 (%24), respectively. The allelic distribution for I and D alleles was found to be 25 (60%) and 17 (40%), respectively. The mean VO2max of all the athletes was calculated as 47.52 ml. The mean VO2max of the II, ID, and DD genotypes were 49.74ml, 47.34 ml, and 46.43 ml, respectively. We found that the oxygen utilization capacity increased from the DD genotype to the II genotype. However, this increase was not statistically significant (p> 0.05). In order to confirm our findings, it is recommended that larger prospective studies depending on the effect of the relevant polymorphisms needed to be carried out.

Effects of static stretching duration on muscle stiffness and blood flow in the rectus femoris in adolescents.

AIMS: To compare the effects of 2 and 5 min of passive static stretching (SS) on stiffness and blood flow in the rectus femoris in adolescent athletes using shear wave elastography (SWE) and superb microvascular imaging (SMI).Material and methods: This prospective study included 20 male athletes with median age of 14.5 (12.5-16.5) years. The subjects were divided into two groups based on the SS duration as follows: 2 min (n=10) and 5 min (n=10). At rest and after 2 and 5 min of SS, stiffness and blood flow values were compared in the rectus femoris for each group. Inter-operator reliability was also analysed. RESULTS: There was no significant difference between resting and 2 min of SS in terms of stiffness. The stiffness values decreased significantly from resting to 5 min of SS. The blood flow increased significantly from resting to 2 and 5 min of SS. Inter-operator reliability was moderate to perfect for SWE and SMI measurements (ICC: 0.52-0.83). CONCLUSIONS:  SWE and SMI can be used to acquire reliable quantitative data about muscle stiffness and blood flow in adolescents. While stiffness parameters significantly decreased from resting after only 5 min, blood flow significantly increased both after 2 and 5 min. For physical rehabilitation protocols, 5 min of SS may be chosen to reduce stiffness. For competitions, 2 min of SS may be sufficient for warm-up exercise because it increases the blood flow optimally. Five min of SS may be preferred for the cool-down exercise to enhance recovery.

Effects of passive muscle stiffness measured by Shear Wave Elastography, muscle thickness, and body mass index on athletic performance in adolescent female basketball players.

AIMS: Athletic performance in basketball comprises the contributions of anaerobic and aerobic performance. The aim was to investigate the effects of passive muscle stiffness, using shear wave elastography (SWE), as well as muscle thickness, and body mass index (BMI), on both aerobic and anaerobic performances in adolescent female basketball players.Material and methods: Anaerobic and aerobic (VO2max) performance was assessed using the vertical jump and shuttle run tests, respectively, in 24 volunteer adolescent female basketball players. Passive muscle stiffness of the rectus femoris (RF), gastrocnemius medialis (GM), gastrocnemius lateralis (GL) and soleus muscles were measured by SWE, and the thickness of each muscle was assessed by gray scale ultrasound. The BMI of each participant was also calculated. The relationship between vertical jump and VO2max values, and those of muscle stiffness, thickness, and BMI were investigated via Pearson's correlation and multivariate linear regression analysis. RESULTS: No significant correlation was observed between muscle stiffness and VO2max or vertical jump (p>0.05). There was significant negative correlation between GL thickness and VO2max (p=0.026), and soleus thickness and VO2max (p=0.046). There was also a significant negative correlation between BMI and VO2max (p=0.001). Conclusions: This preliminary work can be a reference for future research. Although our article indicates that passive muscle stiffness measured by SWE is not directly related to athletic performance, future comprehensive studies should be performed in order to illuminate the complex nature of muscles. The  maintenance of lower muscle thickness and optimal BMI may be associated with better aerobic performance.