Marcelo Romanovitch Ribas

Prof. Marcelo Romanovitch Ribas

orcid

Research Focus & Metrics

Academic Career Length

17Years (2010-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

View All Publications
13 February 2020 in Journal of Physical Education
Verified
Journal Article
Open access
PDF file
MRMarcelo Romanovitch Ribas
Marcelo Romanovitch Ribas
MPMeire Ane Schimitka Pereira
Meire Ane Schimitka Pereira
TBThiago Alexandre Barbosa
Thiago Alexandre Barbosa
ALAndre Domingos Lass
Andre Domingos Lass
JBJulio Cesar Bassan
Julio Cesar Bassan
The aim of the present study was to identify the most used techniques by medalists and defeated athletes during the Brazilian Shotokan Karate Championship of 2017. Eleven fights involving thirteen athletes (28.5±3.7yrs.) who competed in the category “up to 65 Kg 1st KYU” were investigated. Analysis were conducted by six specialists through the observation and register technique using the tactical and technical spreadsheet Scout Karate. The Anova test was used to compare actions and techniques mostly used. The Chi-square test for independent samples was used to verify the existence of significant differences among the techniques used by the winning and defeated athletes (p<0.05). Results show that the most frequent attack during fights was the “Mawashi geri”, 26.3±1.5 times, followed by “Gyaku zuki” with 19.5±2.0 times (p<0.01). The most visualized tactical action during combats was the attack with 47.5±5.5 times (p<0.01). “Mawashi geri” was the mostly used attack (p=0.01) performed by winners (71.4%) when compared with the defeated athletes (28.6%). The results indicate that the “Mawashi geri” attack was the most assertive decision used in the category “up to 65 Kg 1st KYU”.

MRMarcelo Romanovitch Ribas
Marcelo Romanovitch Ribas
FFábio Schneider
Fábio Schneider
DRDanieli Isabel Romanovitch Ribas
Danieli Isabel Romanovitch Ribas
ALAndre Domingos Lass
Andre Domingos Lass
Badicu GeorgianBadicu Georgian
Badicu Georgian
JBJulio Cesar Bassan
Julio Cesar Bassan
Although the studied polymorphisms affect muscular proteins, aerobic adaptations, and recovery, their influence on the anthropometric variables and performance in ultramarathon runners is still poorly understood. This study aimed to determine the influence of ACTN3 R577X, ACE I/D, and CK MM A/G NcoI polymorphisms on the changes in the anthropometric variables and running time of 105 km mountain runners, in which 22 male Brazilian elite athletes (35.9 ± 6.5 years) were evaluated. Genotyping of the R577X (RR, RX, and XX), ACE I/D (DD, ID, and II), and CK MM A/G Ncol (AA, AG, and GG) polymorphisms was performed using the Polymerase Chain Reaction–Restriction Fragment Length Polymorphism (PCR-RFLP) technique with DNA extracted from saliva. Body composition was determined via bioimpedance. Pre- and post-race weight differences were observed on athletes with the AA genotype (77.1 ± 5.9 kg; 74.6 ± 5.6 kg) compared with those with the AG genotype (74.5 ± 8.0 kg; 68 ± 5.1 kg) (p = 0.02; p = 0.02). The RR genotype showed a correlation between BMI and running time (R = 0.97; p = 0.004). The genotype II showed a correlation with % fat and fat mass concerning running time (R = 0.91; p = 0.003; R = 0.99; p < 0.0001). The AA genotype was associated with post-race weight and lean mass loss, while the RR genotype correlated with BMI, and the genotype II correlated with % body fat and fat mass in relation to times in the 105 km mountain ultramarathon.

1 December 2020 in Revista Brasileira de Medicina do Esporte
Verified
Journal Article
Open access
PDF file
MRMarcelo Romanovitch Ribas
Marcelo Romanovitch Ribas
HZHiago Augusto Zonatto
Hiago Augusto Zonatto
MRMarcelo Romanovitch Ribas
Marcelo Romanovitch Ribas
JBJulio Cesar Bassan
Julio Cesar Bassan
Introduction: Genetic factors appear to explain why some athletes perform better in competition and training than their peers. Objective: To determine the occurrence of R577X polymorphism of the ACTN3 gene in mountain runners. Methods: The sample consisted of 19 female mountain runners with a mean age of 41.2 ± 6.1 years. Genotyping of R577X polymorphism of the ACTN3 gene was performed by the polymerase chain reaction (PCR) method with DNA extracted from saliva. The genotypic and allelic frequencies of the athletes were evaluated and compared with data from the literature. Hardy-Weinberg equilibrium and Chi-square with Yates correction were used, with a significance level of p<0.05. Results: The genotypic distributions did not show any significant differences between the athletes and the control group, with RR = 15.8%, RX = 57.9%, XX = 26.3%. In regard to allelic distribution, the nonfunctional allele was higher in the study group than in the control group, with R = 44.7%, X = 55.3% for p = 0.0350. Conclusion: The data revealed a possible relationship between the ACTN3 X allele and athletic performance in Brazilian female mountain runners. Level of evidence II; Development of diagnostic criteria in consecutive patients (with “gold” reference standard applied).

20 February 2025 in Nutrients
Verified
Journal Article
Open access
PDF file
MRMarcelo Romanovitch Ribas
Marcelo Romanovitch Ribas
DRDanieli Isabel Romanovitch Ribas
Danieli Isabel Romanovitch Ribas
PFPriscila Fernandes
Priscila Fernandes
Badicu GeorgianBadicu Georgian
Badicu Georgian
ELElto Legnani
Elto Legnani
JBJulio Cesar Bassan
Julio Cesar Bassan
Objectives/Background: This study investigated the influence of acid–base and electrolyte balance on the performance of female athletes in a 45 km ultramarathon. The aim was to analyze the impact of these variables on performance, particularly in athletes with varying completion times. Methods: Nineteen female athletes (mean age: 35.9 ± 6.5 years) were divided into three groups based on their race completion times: faster, intermediate, and slower. Blood samples were collected before and after the race to assess biochemical variables and arterial blood gases. Results: Significant differences in potassium (K+) levels were found in the intermediate (p = 0.003, adjusted p = 0.01) and slower (p = 0.006, adjusted p = 0.03) groups. Hematocrit (Hct) showed a significant reduction in the intermediate group (p = 0.007, adjusted p = 0.04). In arterial blood gas variables, significant reductions in HCO3− and pCO2 were observed in the faster (HCO3−: p = 0.002, adjusted p = 0.008; pCO2: p = 0.007, adjusted p = 0.02) and intermediate (HCO3−: p = 0.005, adjusted p = 0.02) groups. In the slower group, significant reductions in pH (p = 0.001, adjusted p = 0.004) and HCO3− (p = 0.001, adjusted p = 0.004) were found. The correlation between post-race Na+ levels and performance was significant in the intermediate group (p = 0.01, adjusted p = 0.02). Conclusions: Acid–base and electrolyte imbalances significantly affect ultramarathon performance, with a greater impact observed in athletes with slower times. These findings highlight the importance of strategies to optimize electrolyte and acid–base balance in endurance events.

19 November 2024 in Nutrients
Verified
Journal Article
Open access
PDF file
MRMarcelo Romanovitch Ribas
Marcelo Romanovitch Ribas
FFábio Schneider
Fábio Schneider
DRDanieli Isabel Romanovitch Ribas
Danieli Isabel Romanovitch Ribas
Badicu GeorgianBadicu Georgian
Badicu Georgian
ABAna Claudia Bonatto
Ana Claudia Bonatto
JBJulio Cesar Bassan
Julio Cesar Bassan
Background/Objectives: This study focused on a group of 22 elite male mountain runners from Brazil (average age of 35.9 ± 6.5 years) with the objective of exploring the possible roles of the ACTN3 R577X, ACE I/D, and CK MM A/G NcoI genetic variants in shaping electrochemical profiles and maintaining acid-base homeostasis during a 105-km ultramarathon. Methods: Genotyping for each polymorphism (ACTN3: RR, RX, XX; ACE: DD, ID, II; CK MM: AA, AG, GG) was conducted using PCR-RFLP (Polymerase Chain Reaction-Restriction Fragment Length Polymorphism), and saliva samples were used to obtain DNA. Analyses of electrochemical and acid-base disturbances were performed in real time. Results: It was observed that athletes who completed the race in less time had lower calcium concentrations (Rs = 0.35; p = 0.016). Pre-race, the RX genotype showed a 14.19% reduction in potassium levels compared to RR (p = 0.01). The GG genotype showed potassium levels 19.36% higher than AA (p = 0.01) and a 6.11% increase in hematocrit values compared to AA (p = 0.03). Additionally, the AG genotype exhibited hematocrit values 5.44% higher than AA (p = 0.03). Post-race, the XX genotype demonstrated higher hematocrit values compared to RX, with an increase of 8.92% (p = 0.03). The II genotype showed a 0.27% increase in pH compared to ID (p = 0.02) and a 20.42% reduction in carbon dioxide levels (p = 0.01). Conclusions: The findings emphasize the impact of the examined polymorphisms on the modulation of electrochemical factors and the maintenance of acid-base equilibrium in athletes during 105 km ultramarathons.

22 March 2010 in Uningá Journal
Verified
Journal Article
Open access
PDF file
MRMarcelo Romanovitch Ribas
Marcelo Romanovitch Ribas
RPRenan DE Lima Pinto
Renan DE Lima Pinto
RWRenata Wassmansdorf
Renata Wassmansdorf
RARoney José Alberti
Roney José Alberti
JBJulio Cesar Bassan
Julio Cesar Bassan
O presente estudo teve como objetivo, descrever as características antropométricas emdiferentes etapas do treinamento em atletas de futebol da categoria Junior (sub-20). Aamostra do estudo foi composta de 23 atletas de futebol de campo do estado do Paraná,do sexo masculino, com idade entre 18 e 20 anos, que possuíam no mínimo um ano detreinamento na modalidade futebol, com volume de treino de cinco vezes por semana e4 horas diárias. Foram excluídos os goleiros, devido às diferenças metodológicas detreinamento. Os atletas foram avaliados da seguinte forma: 1ª avaliação (précompetição)antes do início do campeonato, 2ª, 3ª e 4ª avaliações (competitivo), 5ªavaliação (transição) após o término do campeonato. Foram avaliadas massa corporal,altura e percentual de gordura através das medidas das dobras cutâneas. Foi constatadoum pequeno aumento na massa corporal total e massa isenta de gordura, situação quereflete, progresso na preparação física dos jogadores, pois maior massa muscularfavorece as aptidões físicas.