Browsing by Author "Baltazar Martins, Gabriel"
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Item ACTN3 R577X Genotype and Exercise Phenotypes in Recreational Marathon Runners.(Genes, 2019) Del Coso, Juan; Moreno, Víctor; Gutiérrez Hellín, Jorge; Baltazar Martins, Gabriel; Ruiz Moreno, Carlos; Aguilar Navarro, Millán; Lara, Beatriz; Lucía, AlejandroHomozygosity for the X-allele in the ACTN3 R577X (rs1815739) polymorphism results in the complete absence of -actinin-3 in sarcomeres of fast-type muscle fibers. In elite athletes, the ACTN3 XX genotype has been related to inferior performance in speed and power-oriented sports; however, its influence on exercise phenotypes in recreational athletes has received less attention. We sought to determine the influence of ACTN3 genotypes on common exercise phenotypes in recreational marathon runners. Methods: A total of 136 marathoners (116 men and 20 women) were subjected to laboratory testing that included measurements of body composition, isometric muscle force, muscle flexibility, ankle dorsiflexion, and the energy cost of running. ACTN3 genotyping was performed using TaqMan probes. Results: 37 runners (27.2%) had the RR genotype, 67 (49.3%) were RX and 32 (23.5%) were XX. There was a di erence in body fat percentage between RR and XX genotype groups (15.7 5.8 vs. 18.8 5.5%; e ect size, ES, = 0.5 0.4, p = 0.024), whereas the distance obtained in the sit-and-reach-test was likely lower in the RX than in the XX group (15.3 7.8 vs. 18.4 9.9 cm; ES = 0.4 0.4, p = 0.046). Maximal dorsiflexion during the weight-bearing lunge test was di erent in the RR and XX groups (54.8 5.8 vs. 57.7 5.1 degree; ES = 0.5 0.5, p = 0.044). Maximal isometric force was higher in the RR than in the XX group (16.7 4.7 vs. 14.7 4.0 N/kg; ES = �����0.5 0.3, p = 0.038). There was no di erence in the energy cost of running between genotypes (~4.8 J/kg/min for all three groups, ES ~0.2 0.4). Conclusions: The ACTN3 genotype might influence several exercise phenotypes in recreational marathoners. Deficiency in -actinin-3 might be accompanied by higher body fatness, lower muscle strength and higher muscle flexibility and range of motion. Although there is not yet a scientific rationale for the use of commercial genetic tests to predict sports performance, recreational marathon runners who have performed such types of testing and have the ACTN3 XX genotype might perhaps benefit from personalized strength training to improve their performance more than their counterparts with other ACTN3 genotypes.Item Effect of ACTN3 R577X Genotype on Injury Epidemiology in Elite Endurance Runners´.(Genes, 2021) Gutiérrez Hellín, Jorge; Baltazar Martins, Gabriel; Aguilar Navarro, Millán; Oliván, Jesús; Del Coso, JuanThe p.R577X polymorphism (rs1815739) in the ACTN3 gene causes individuals with the ACTN3 XX genotype to be deficient in functional α-actinin-3. Previous investigations have found that XX athletes are more prone to suffer non-contact muscle injuries. This investigation aimed to determine the influence of the ACTN3 R577X polymorphism in the injury epidemiology of elite endurance athletes. Using a cross-sectional experiment, the epidemiology of running-related injuries was recorded for one season in a group of 89 Spanish elite endurance runners. ACTN3 R577X genotype was obtained for each athlete using genomic DNA samples. From the study sample, 42.7% of athletes had the RR genotype, 39.3% had the RX genotype, and 18.0% had the XX genotype. A total of 96 injuries were recorded in 57 athletes. Injury incidence was higher in RR runners (3.2 injuries/1000 h of running) than in RX (2.0 injuries/1000 h) and XX (2.2 injuries/1000 h; p = 0.030) runners. RR runners had a higher proportion of injuries located in the Achilles tendon, RX runners had a higher proportion of injuries located in the knee, and XX runners had a higher proportion of injuries located in the groin (p = 0.025). The ACTN3 genotype did not affect the mode of onset, the severity, or the type of injury. The ACTN3 genotype slightly affected the injury epidemiology of elite endurance athletes with a higher injury rate in RR athletes and differences in injury location. However, elite ACTN3 XX endurance runners were not more prone to muscle-type injuries.Item Gender Differences in Prevalence and Patterns of Dietary Supplement Use in Elite Athletes.(Research Quarterly for Exercise and Sport, 2020) Aguilar Navarro, Millán; Baltazar Martins, Gabriel; Brito de Souza, Diego; Muñoz Guerra, Jesús; Plata, María del Mar; Del Coso, JuanPurpose: Dietary supplement use by athletes has been the topic of previous research; however, the lack of homogeneity among published studies makes it difficult to analyze the differences, if any, in the patterns of use between male and female athletes. The aim of this study was to determine gender differences in the patterns of dietary supplement use by elite athletes. Methods: A total of 504 elite athletes (329 males and 175 females) participating in individual and team sports completed a validated questionnaire on dietary supplement use during the preceding season. The dietary supplements were categorized according to the latest IOC consensus statement. Results: A higher proportion of male versus female athletes (65.3 versus 56.5%, p < .05) consumed dietary supplements. Both male and female athletes reported a similar mean consumption of dietary supplements (3.2 ± 2.1 versus 3.4 ± 2.3 supplements/season, respectively; p = .45). Protein supplements were the most commonly consumed supplements in male athletes (49.8%) and their prevalence was higher than in female athletes (29.3%, p < .01). In females, multivitamins (39.4%) and branched-chain amino acids (39.4%) were the most commonly consumed supplements and iron supplementation was more prevalent than in males (22.2% versus 10.2%, p = .01). A higher proportion of male athletes relied on themselves to plan dietary supplements use (48.0%), while female appeared to rely more on doctors (34.0%, p < .01). Conclusion: In summary, male athletes had a slightly higher prevalence in the use of supplements than their female counterparts, specifically regarding protein supplements, and were more involved in the self-prescription of supplements.Item Outcomes of adverse analytical findings in individual and team sports.(Bioanalysis, 2021) Aguilar Navarro, Millán; Baltazar Martins, Gabriel; Salinero, Juan José; Muñoz Guerra, Jesús; Plata, María del Mar; Lara, Beatriz; Del Coso, JuanThe aim of this investigation was to describe the outcomes of the adverse analytical findings in different Olympic sports. The data included were gathered from the World Anti-Doping Agency Anti-doping Rule Violations Reports (2013–2017). Weightlifting (78.1 ± 9.4%) wrestling (73.2 ± 18.5%) and volleyball (68.3 ± 18.7%) were the sports with the highest proportion of cases that ended in an antidoping sanction. Gymnastics (45.1 ± 10.1%), triathlon (32.6 ± 11.9%) and shooting (29.9 ± 14.1%) were the sports with a higher frequency of cases that were not sanctioned due to medical reasons. Gymnastics (22.4 ± 18.4%), boxing (23.2 ± 16.0%) and taekwondo (17.3.1 ± 16.4%) presented the highest proportion of cases that are still pending resolution. The proportion of cases that ended in no sanction was higher in fencing (26.2 ± 22.7%), skating (23.6 ± 35.1%) and tennis (18.6 ± 26.5%). These results indicate that the sanctions derived from antidoping rule violations were not uniform in all sports disciplines.Item p-Synephrine, the main protoalkaloid of Citrus aurantium, raises fat oxidation during exercise in elite cyclists.(European Journal of Sport Science, 2021) Gutiérrez Hellín, Jorge; Baltazar Martins, Gabriel; Rodríguez, Iván; Lara, Beatriz; Ruiz Moreno, Carlos; Aguilar Navarro, Millán; Del Coso, JuanThe aim of this study was to investigate the acute effects of p-synephrine ingestion on substrate oxidation during exercise in elite cyclists. Fifteen elite cyclists volunteered to participate in a double blind, crossover, randomized and placebo-controlled experimental trial. During two different trials, participants either ingested a placebo (cellulose) or 3 mg/kg of p-synephrine. After 60 min for substances absorption, participants performed an incremental maximal cycle ergometer test until volitional fatigue (25 W/min). Breath-by-breath gas exchange data was continuously recorded during the entire test to estimate energy expenditure, carbohydrate oxidation, and fat oxidation rates by stoichiometric equations. Heart rate was continuously measured by using a heart rate monitor. The ingestion of p-synephrine had no significant effects on energy expenditure (F = 0.71, P = 0.40) or heart rate (F = 0.66, P = 0.43) during exercise. However, there was a main effect of p-synephrine to increase the rate of fat oxidation over the placebo (F = 5.1, P = 0.04) and the rate of fat oxidation was higher with p-synephrine in the following loads: 45 ± 2%, 51 ± 3%, 62 ± 3%, 67 ± 4%, 79 ± 5% and 85 ± 5% of the maximum wattage obtained in the test (all P < 0.05). The ingestion of p-synephrine did not modify the maximal rate of fat oxidation during the ramp test (mean value; 95%CI = 0.91; 0.79–1.03 vs 1.01; 0.91–1.11 g/min, respectively, P = 0.06) nor the exercise intensity at which maximal fat oxidation was achieved (i.e. Fatmax = 49; 48–53 vs 50; 47–51% Wmax, P = 0.52). Acute p-synephrine ingestion moved the fat oxidation-exercise intensity curve upwards during an incremental cycling test without affecting Fatmax.