Biblioteca Digital do IPB

Publications Repository of the Polytechnic Institute of Bragança

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The Digital Library of IPB (Biblioteca Digital do IPB), promotes and provides open access to scientific literature produced by the IPB academic community, promoting integration, visibility and sharing of scientific information granting the preservation of intellectual memory of the Instituto Politécnico de Bragança.

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Recent Submissions

Sex differences in performance and pacing in the greatest Quintuple Iron ultra-triathlon race in history: The IUTA World Championship 2024 in France

Publication . Knechtle, Beat; Leite , Luciano Bernardes; Duric, Sasa; Cuk, Ivan; Andrade, Marilia Santos; Scheer, Volker; Nikolaidis, Pantelis Theo; Weiss, Katja; Rosemann, Thomas; Forte, Pedro; Ratko Peric

Pacing in ultra-triathlon has been investigated by analyzing lap times from Double to Deca Iron ultra-triathlon for World Cup races but not for a World Championship. The present study aimed to investigate pacing in ultra-triathletes competing in the fastest and largest World Championship in Quintuple Iron ultra-triathlon ever held in history. A total of 11 female and 24 male finishers who completed the 2024 Quintuple Ultra Triathlon World Championship in Colmar, France, were analyzed. Independent t-tests assessed sex-based performance variations with effect sizes (Cohen's d). A two-way ANOVA evaluated the effects of sex and performance quartiles on cycling and running, with eta squared (eta(2)) used to measure effect sizes. Overall, men were slower in swimming and cycling and faster in running and overall race time. The variability in lap times was similar in cycling for both women and men but higher in running for women. There was a significant interaction between sex and performance quartiles in cycling but not running. For cycling, the variability in performance was higher in men compared to women; for running, it was similar for both women and men. The finding that women outperformed men in swimming and cycling, likely due to the elite nature of the World Championship, which featured a highly selected and committed female cohort with a high completion rate. While both sexes showed consistent pacing in cycling, women exhibited greater variability in running, possibly due to more frequent breaks.

2025Journal article

Open access

Freestyle master’s swimming: Nationality, sex, and performance trends in World Aquatics competitions (1986–2024)

Publication . Ahmad, Wais; Wilhelm, Matthias; Moreitz, Sascha; Andrade, Marilia Santos; Forte, Pedro; Stanula, Arkadiusz; Nikolaidis, Pantelis Theo; Cuk, Ivan; Thuany, Mabliny; Weiss, Katja; Rosemann, Thomas; Hill, Lee; Seffrin, Aldo; Knechtle, Beat; Emiliano Cè

In sports science, freestyle swimming has been thoroughly studied for particular performance-related factors. Nonetheless, it is unknown what countries the top freestyle swimmers are from, especially not for age group swimmers. In addition, the existing research on the performance of master freestyle swimmers has yet to confirm that male swimmers achieve faster times than their female counterparts across all age groups and distances. The current study looked into the nationalities and sexes of the top freestyle swimmers in each age group in World Aquatics competitions for the 50m, 100m, 200m, 400m, and 800m events from 1986 to 2024. Methods The data (derived from (www.worldaquatics.com/masters/archives/masters-archives) were presented using mean, standard deviation, maximum and minimum values, and/or confidence intervals. The year of competition, age, age group, stroke, distance, and first and last names of each swimmer were noted. The nations were then divided into six groups: one group comprising all other countries and the top five nations with the greatest number of appearances in the top 10 fastest freestyle swimming times by distance each year. Results In freestyle swimming, most swimmers (30.6%) competed in the 50m event (n = 25,094, 10,909 female and 14,185 male), followed by the 100m event (25.6%, n = 20,961, 8,796 female and 12,165 male), the 200m event (17.4%, n = 14,309, 6,729 female and 7,580 male), the 400m event (13.4%, n = 10,956, 5,363 female and 5,593 male), and the 800m event (12.6%, n = 10,317, 5,179 female and 5,138 male). The results from the generalized linear models indicate that sex, age group, and the interaction between sex and age group all had significant effects on the 50m, 100m, 200m, 400m, and 800m races. Specifically, for the 50m races, the effect of sex was significant (x(2) (1) = 3451.941, p < 0.001), as was the effect of age group (chi(2) (13) = 19,295.169, p < 0.001), and the interaction between sex and age group (chi (2) (13) = 654.671, p < 0.001). Conclusion The USA demonstrates quantitative dominance by contributing the greatest number of top 10 performers. Additionally, the study highlights significant sex-based performance differences, with males generally outperforming females in all age categories. This study comprehensively analyzes the performance trends observed in freestyle master swimming for nearly four decades.

2025Journal article

Open access

Behavioral regulation in sport questionnaire and sport motivation scale-II: a scale comparison

Publication . Bica, Joana; Jacinto, Miguel; Matos, Rui; Amaro, Nuno; Antunes, Raul; Couto, Nuno; Cid, Luís; Forte, Pedro; Monteiro, Diogo

This study compared the psychometric properties of two primary instruments for assessing sport motivation based on Self-Determination Theory: the Sport Motivation Scale-II (SMS-II) and the Behavioral Regulation in Sport Questionnaire (BRSQ). A cross-sectional analysis evaluated the scales' internal consistency, factor structure, convergent and discriminant validity, and model fit, which required post-hoc modifications. Measurement invariance and adherence to the theoretical simplex pattern were also tested. The BRSQ demonstrated generally acceptable reliability, while the SMS-II showed deficiencies in its introjected, external, and amotivation subscales. Both scales faced validity challenges in distinguishing adjacent motivational constructs. Although measurement invariance was supported, correlations deviated from the theoretical quasi-simplex pattern. The BRSQ appears more robust, but neither scale is flawless. Researchers must select instruments aligned with their specific objectives and interpret scores cautiously due to these psychometric limitations. This underscores the need for refined tools to better capture the dynamic complexity of motivation in sports.

2025Journal article

Open access

Assessing the prebiotic potential of xylooligosaccharides produced by one-step fermentation using agro-residue

Publication . Cordeiro, Ana; Fernandes, Andreia; Sousa, Joana; Cardoso, Beatriz; Alves, Joana; Silvério, Sara; Peres, António M.; Rodrigues, Lígia R.; Amorim, Cláudia

A prebiotic is defined as a substrate that is selectively utilized by host microrganisms, conferring a health benefit

2023Conference poster

Open access

Analysis of failure in sheet metal stamping

Publication . Kawakami, Thiago Fernando; Mesquita, L.M.R.; Morais, Osmano; Souza, Janaína Fracaro de

In the past, forming dies were developed through a trial-and-error process, where failures were identified and the die shape was subsequently adjusted. With the advent of the Finite Element Method (FEM), this process became more efficient, as FEM could be used to simulate and analyze forming results. Meanwhile, the tightening of automotive emission standards has increased the demand for more suitable materials, leading to stricter safety margins to achieve the desired weight reduction. In this work, the FEM will be employed to assess whether the failures observed in the industrial cold stamping process could have been predicted. To achieve this, several tensile tests will be conducted to characterize the material properties of two Ferritic Stainless Steel (FSS), EN 1.4509 and EN 1.4512. Using Digital Image Correlation (DIC), the anisotropy coefficients will be obtained and used to model the Barlat (1989) and Hill (1948) yield criteria. The Forming Limit Diagram (FLD) will be predicted through Abspoel and Keeler and Brazier methods. Finally, FEM simulations will be carried out using Ansys Forming software on two different stamped parts. The first part involves seven forming operations, while the second is limited to only the initial operation. In the first part, an increased tendency for wrinkling is observed near the notches, resulting in a local increase in thickness. In the second part, two of three failures observed in industrial production are successfully reproduced with the default parameters. Subsequently, the Lankford Ratio is varied by ±10%, which leads to the occurrence of the final failure. This highlights a strong dependency on the Lankford Ratio.

2025Master thesis

Open access