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The purpose of this study was to compare the muscular performance of Brazilian MMA athletes in strength and power tests for different genotype groups of ACTN3 R577X polymorphism. Eighteen male professional Brazilian MMA athletes (RR=6, RX=9, XX=3) participated in this study. Subjects performed handgrip test, supine and squat exercises in 1RM and 70% of 1RM tests, and countermovement jump test. The subjects’ blood samples were drawn from an antecubital arm vein. Genomic DNA was extracted from leukocytes using the salting-out technique. ACTN3 R577X polymorphism was determined by PCR test. Although the findings indicate there was no association between the ACTN3 and upper body muscle performance (handgrip test, 1RM supine test, and 70% of 1RM supine test) (P>0.05), the MMA athletes with ACTN3 RX genotype presented better local muscle endurance than the RR athletes (P=0.02). Also, the dominant model (RR vs. RX+XX) of ACTN3 genotype presented better local muscle endurance (P=0.04). Regarding the explosive muscle power of the MMA athletes’ lower limbs, the recessive model (RR+RX vs. XX) of ACTN3 genotype showed greater responses (P=0.03).

This article is free to read on the publishers website This study aimed identifying the effects of a 130-km cycling race on indices of physiological recovery markers of during a 72-h period. Thirteen endurance trained male cyclists underwent a collection of indices for measuring neuromuscular parameters, muscle soreness and heart rate variability at five different moments of data collections: before, after and at 24, 48 and 72-h following a cycling race. Results indicate that the neuromuscular parameters scores decreased after the race (maximal voluntary isometric contraction: 13.61%, p < .05; electromyography: 21.65%, p = .002), yet some parameters returned to baseline values at 72-h afterwards (maximal voluntary isometric contraction: p > .05) while other neuromuscular parameters values remained lower throughout the 72-h recover period (electromyography: 10.62%, p < .05). Muscle soreness increased after the race (p < .001) and returned to baseline values 48-h thereafter (p > .05). The heart rate variability values increased after the race and remained higher for 72-h afterwards (p < .05). These findings show that a 130-km cycling race has a noteworthy effect on indices of neuromuscular parameters, muscle soreness and heart rate variability responses. Moreover, these results suggest that a 72-h recovery period does not appear to be enough for long-distance cyclist and reinforce the propositions within scientific literature concerning athletes involved in endurance cycling need for a sufficient recovery period.

ACTN3 R577X and ACE I/D genotype frequencies of professional soccer players in Brazil. JEPonline 2017;10(1):1-10. The purpose of this study was to identify the genotype and allele distribution of ACTN3 and ACE genes in professional soccer players and to compare its distribution to the general population. Forty male professional players of a Brazilian first division soccer team participated in this study. Firstly, blood samples were drawn from an antecubital arm vein, and then, genomic DNA was extracted from leukocytes using the salting-out technique. Lastly, ACTN3 and ACE polymorphism was determined by the polymerase chain reaction (PCR). Regarding to the ACTN3 R3557X gene of soccer player frequency distributions, the genotype RX(50%)>RR(45%)>XX(5%) and the allele R(70%)>X(30%). About the ACE I/D gene distribution, the genotype ID(57.5%)>DD(30%)>II(12.5%) and allele D(58.8%)>I (41.2%). However, the soccer player genotype and allele frequencies were not different to the control groups. In conclusion, our data indicated that ACTN3 R577X and ACE I/D are not the best genetic marker for identifying a talent soccer player. Nevertheless, these results suggest that men who have the combination of both genotypes ‘ACTN3 RX’ and ‘ACE ID’ in these two different genes, are more likely to be a professional soccer player when compared to other genotype combinations.

BACKGROUND: Pre-exercise stretching is a commonly used practice by many competitive and recreational athletes. However, the effects of stretching on muscle performance are still incongruous. Furthermore, there is conflicting evidence regarding the intensity of stretching and the effect it has on muscular strength. OBJECTIVE: To investigate the effects of two different intensity levels of passive static stretching protocols on concentric knee extension strength. METHODS: Twenty-two male recreational athletes involved in regular resistance training programs were evaluated using a randomized design. Subjects performed an isokinetic test of the knee extensors following either maximal intensity static stretching, submaximal intensity static stretching, or no stretching. RESULTS: The only significant difference in the peak moment, amounting to 10.5%, was noted between maximal intensity stretching and no stretching. CONCLUSION: Maximal intensity stretching of the quadriceps may adversely affect the acute concentric moment production capacity of these muscles.

The purpose of the present investigation was to identify the effects of a 130km cycling race on indices of biochemical indirect markers of muscle damage and muscle soreness responses during a 72-hour recovery period. Fifteen endurance-trained male cyclists which were competing for more than 2 years and were involved in systematic training at least of 3 days/week underwent a collection of indirect biochemical markers of muscle damage (CK, LDH, Myo) and delayed onset of muscle soreness (DOMS), at five different moments of data collection: before (PRE) and immediately after (POST) a 130-km cycling race, and 24, 48, 72 hours following the cycling race. CK and LDH plasma concentrations significantly increased POST-race (p < 0.001) and remained high throughout the 72 hour recover period (CK: p < 0.05; LDH: p < 0.001). Myo increased significantly POST-race (p < 0.001) and returned to the PRE-race values 24 hours thereafter (p < 0.05). DOMS increased significantly POST-race (p < 0.001) and returned to the PRE-race values at 48 hours after (p > 0.05). A 130-km cycling race has a noteworthy effect on indices of biochemical indirect markers of muscle damage and muscle soreness responses, indicating that 72 hour recovery period do not seems to be enough for long-distance cyclist, and reinforce the propositions of scientific literature about the need of a sufficient recovery period for cycling endurance athletes.