Are Genome-Wide Association Study Identified Single-Nucleotide Polymorphisms Associated With Sprint Athletic Status? A Replication Study With 3 Different Cohorts.

PURPOSE: To replicate previous genome-wide association study identified sprint-related polymorphisms in 3 different cohorts of top-level sprinters and to further validate the obtained results in functional studies. METHODS: A total of 240 Japanese, 290 Russians, and 593 Brazilians were evaluated in a case-control approach. Of these, 267 were top-level sprint/power athletes. In addition, the relationship between selected polymorphisms and muscle fiber composition was evaluated in 203 Japanese and 287 Finnish individuals. RESULTS: The G allele of the rs3213537 polymorphism was overrepresented in Japanese (odds ratio [OR]: 2.07, P = .024) and Russian (OR: 1.93, P = .027) sprinters compared with endurance athletes and was associated with an increased proportion of fast-twitch muscle fibers in Japanese (P = .02) and Finnish (P = .041) individuals. A meta-analysis of the data from 4 athlete cohorts confirmed that the presence of the G/G genotype rather than the G/A+A/A genotypes increased the OR of being a sprinter compared with controls (OR: 1.49, P = .01), endurance athletes (OR: 1.79, P = .001), or controls + endurance athletes (OR: 1.58, P = .002). Furthermore, male sprinters with the G/G genotype were found to have significantly faster personal times in the 100-m dash than those with G/A+A/A genotypes (10.50 [0.26] vs 10.76 [0.31], P = .014). CONCLUSION: The rs3213537 polymorphism found in the CPNE5 gene was identified as a highly replicable variant associated with sprinting ability and the increased proportion of fast-twitch muscle fibers, in which the homozygous genotype for the major allele (ie, the G/G genotype) is preferable for performance.

Caffeine and Exercise Performance: Possible Directions for Definitive Findings.

Caffeine is one of the most studied supplements in the world. Studies correlate its use to increased exercise performance in endurance activities, as well as its possible ergogenic effects for both intermittent and strength activities. Recent findings show that caffeine may increase or decrease exercise performance. These antagonist responses may occur even when using the same dosage and for individuals with the same characteristics, making it challenging to explain caffeine's impact and applicability. This review article provides an analytic look at studies involving the use of caffeine for human physical performance, and addresses factors that could influence the ergogenic effects of caffeine on different proposed activities. These factors subdivide into caffeine effects, daily habits, physiological factors, and genetic factors. Each variable has been focused on by discussions to research related to caffeine. A better understanding and control of these variables should be considered in future research into personalized nutritional strategies.

Total genotype score and athletic status: An exploratory cross-sectional study of a Brazilian athlete cohort.

The purpose of the present study was to explore the ability of the total genotype score (TGS) for evaluation of the polygenic profile of elite athletes. Data from a Brazilian athlete cohort were used in this study, which included 368 athletes and 818 nonathletes. The TGS targeted to power athletes was computed using from two to 10 associated polymorphisms. In all models, the power group showed a higher TGS mean compared to the nonathlete group. In particular, scores using more associated polymorphisms showed stronger differences (P < 0.0001). Moreover, the more polymorphisms included in the score, the greater its discriminatory power. The frequency distribution of individuals according to the TGS computed using 10 associated polymorphisms showed that both the power group and the replication group were overrepresented in scores ≥60.0 (P < 0.0075). Individuals with a score ≥60.0 had an increased odds ratio (OR) of being an elite athlete compared to the nonathlete group (OR > 2.03; P < 0.006), although there were athletes with TGS values ranging from 15.0 to 90.0. By setting 60.0 as the cutoff point, the sensitivity and specificity of the TGS was approximately 30% and 82.5%, respectively. In conclusion, the TGS computed using 10 associated polymorphisms proved to be effective in discriminating the target athlete group, but with limited accuracy as evidenced by its sensitivity rate.

Analysis of sports-relevant polymorphisms in a large Brazilian cohort of top-level athletes.

In recent years, there have been an increasing number of genetic variants associated with athletic phenotypes. Here, we selected a set of sports-relevant polymorphisms that have been previously suggested as genetic markers for human physical performance, and we examined their association with athletic status in a large cohort of Brazilians. We evaluated a sample of 1,622 individuals, in which 966 were nonathletes, and 656 were athletes: 328 endurance athletes and 328 power athletes. Only the AGT M268T minor allele was nominally associated with the endurance status. Conversely, we found that seven polymorphisms are more frequent in power athletes (MCT1 D490E, AGT M268T, PPARG P12A, PGC1A G482S, VEGFR2 Q472H, NOS3 C/T, and ACTN3 R577X). For all of these polymorphisms, power athletes were more likely than nonathletes or endurance athletes to carry the major allele or the homozygous genotype for the major allele. In particular, MCT1 D490E, AGT M268T, NOS3 C/T, and ACTN3 R577X showed stronger associations. Our findings support a role for these variants in the achievement of power athletic status in Brazilians: MCT1 D490E (T allele), AGT M268T (G allele), PPARG (C allele), PGC1A G482S (C allele), VEGFR2 Q472H (T allele), NOS3 C/T (T allele), and ACTN3 R577X (R allele).

The AGTR2 rs11091046 (A>C) polymorphism and power athletic status in top-level Brazilian athletes.

The main purpose of this study was to investigate if the rs11091046 (A>C) polymorphism in AGTR2 gene is associated with athletic status in top-level athletes from Brazil. Since the AGTR2 gene is located on the X chromosome, the case-control association study was done separately for women and men. The female cohort was composed of 205 athletes and 241 non-athletes, and the male cohort was composed of 419 athletes and 490 non-athletes. We did not identify an association between the C-allele and the endurance phenotype. However, power athletes had a higher frequency of the A-allele. In women, A/A genotype was overrepresented in international-level power group compared with non-athletes or international-level endurance athletes (23.2% vs. 16.6% or 8.8%, respectively; p < 0.05). In men, the A-allele frequency observed in power athletes or international-level power athletes was statistically different from that observed in non-athletes (51.6% or 57.8% vs. 40.4%; p < 0.009). Furthermore, men sprinters with the A-allele showed significantly faster personal best times for the 100 m than those with the C-allele (10.56 ± 0.32 s vs. 10.93 ± 0.49 s; p < 0.02). In conclusion, it was found that the AGTR2 A-allele is a candidate genetic marker for top-level power athletes.

Single Nucleotide Polymorphisms in Carnosinase Genes (CNDP1 and CNDP2) are Associated With Power Athletic Status.

Carnosine (ß-alanyl-L-histidine), abundantly found in skeletal muscle, plays an important role during exercise, especially for high-intensity contractions. Variability in muscle carnosine content between individuals exists and may also be explained by different genetic bases, although no study has addressed the association of polymorphisms in genes related to carnosine metabolism in athletes. This study aimed to investigate the frequency of single nucleotide polymorphisms (SNPs) in the carnosinase genes (CNDP1 and CNDP2) in a large Brazilian cohort of athletes and nonathletes. Eight SNPs were compared between a representative cohort of elite athletes from Brazil (n = 908) and a paired group of nonathletes (n = 967). The athletes were stratified into three groups: endurance (n = 328), power (n = 415), and combat (n = 165). The CNDP2 rs6566810 (A/A genotype) is overrepresented in endurance athletes, but only in international-level endurance athletes. Three SNPs (CNDP2 rs3764509, CNDP2-CNDP1 rs2346061, and CNDP1 rs2887) were overrepresented in power athletes compared with nonathletes. Carriers of the minor allele had an increased odds ratio of being a power athlete. For the rs2346061, no significant difference was observed in genotype frequencies between power and combat sports athletes, but for rs2887 the power and combat groups showed an inverse genotype distribution. In conclusion, we found that minor alleles carriers for CNDP2 rs3764509 (G-allele), CNDP2-CNDP1 rs2346061 (C-allele), and CNDP1 rs2887 (A-allele) are more likely to be a power athlete. These polymorphisms may be novel genetic markers for power athletes. Furthermore, these results are suggestive of a distinct CNDP genotype for sporting development.

Embryonic stem cells improve skeletal muscle recovery after extreme atrophy in mice.

INTRODUCTION: We injected embryonic stem cells into mouse tibialis anterior muscles subjected to botulinum toxin injections as a model for reversible neurogenic atrophy. METHODS: Muscles were exposed to botulinum toxin for 4 weeks and allowed to recover for up to 6 weeks. At the onset of recovery, a single muscle injection of embryonic stem cells was administered. The myofiber cross-sectional area, single twitch force, peak tetanic force, time-to-peak force, and half-relaxation time were determined. RESULTS: Although the stem cell injection did not affect the myofiber cross-sectional area gain in recovering muscles, most functional parameters improved significantly compared with those of recovering muscles that did not receive the stem cell injection. CONCLUSIONS: Muscle function recovery was accelerated by embryonic stem cell delivery in this durable neurogenic atrophy model. We conclude that stem cells should be considered a potential therapeutic tool for recovery after extreme skeletal muscle atrophy.

Genetics and sport performance: current challenges and directions to the future

In recent years there has been a great progress in molecular biology techniques, which has facilitated the researches on influence of genetics on human performance. There are specific regions of DNA that can vary between individuals. Such variations (i.e., polymorphisms) may, in part, explain why some individuals have differentiated responses to certain stimuli, including the responses to sports training. In a particular sport, the presence of specific polymorphisms may contribute to high levels of performance. Since 1998, several polymorphisms have been associated with athletic phenotypes; however the accumulation of information generated over these 15 years shows that the influence of genetics to sport is extremely complex. In this review, we will summarise the current status of the field, discussing the implications of available knowledge for the practice of professionals involved with the sport and suggesting future directions for research. We also discuss topics related to the importance of polygenic profile characterization of athletes, methods for the identification of new polymorphisms associated with physical performance, the use of genetic testing for predicting competitive success, and how crucial is the genetic profile for the success athletes in competition.

The effects of two different doses of calcium lactate on blood pH, bicarbonate, and repeated high-intensity exercise performance.

We investigated the effects of low- and high-dose calcium lactate supplementation on blood pH and bicarbonate (Study A) and on repeated high-intensity performance (Study B). In Study A, 10 young, physically active men (age: 24 ± 2.5 years; weight: 79.2 ± 9.45 kg; height: 1.79 ± 0.06 m) were assigned to acutely receive three different treatments, in a crossover fashion: high-dose calcium lactate (HD: 300 mg · kg(-1) body mass), low-dose calcium lactate (LD: 150 mg · kg(-1) body mass) and placebo (PL). During each visit, participants received one of these treatments and were assessed for blood pH and bicarbonate 0, 60, 90, 120, 150, 180, and 240 min following ingestion. In Study B, 12 young male participants (age: 26 ± 4.5 years; weight: 82.0 ± 11.0 kg; height: 1.81 ± 0.07 m) received the same treatments of Study A. Ninety minutes after ingestion, participants underwent 3 bouts of the upper-body Wingate test and were assessed for blood pH and bicarbonate 0 and 90 min following ingestion and immediately after exercise. In Study A, both HD and LD promoted slight but significant increases in blood bicarbonate (31.47 ± 1.57 and 31.69 ± 1.04 mmol · L(-1, respectively) and pH levels (7.36 ± 0.02 and 7.36 ± 0.01, respectively), with no effect of PL. In Study B, total work done, peak power, mean power output were not affected by treatments. In conclusion, low- and high-dose calcium lactate supplementation induced similar, yet very discrete, increases in blood pH and bicarbonate, which were not sufficiently large to improve repeated high-intensity performance.