Browsing by Author "Pinto, Mafalda P."
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- Comparison of the Active Drag and Passive Drag Coefficients at the same Swimming Speed Through Experimental MethodsPublication . Lopes, Tiago J.; Pinto, Mafalda P.; Oliveira, João P.; Marinho, Daniel A.; Morais, J. E.; Sampaio, TatianaStudies about drag in swimming usually report or put the focus on its absolute value. However, it is being claimed that the drag coefficient better represents the hydrodynamic profile of a swimmer. Drag is strongly dependent on speed. Thus, increases in speed will lead to increases in drag. This could lead to misleading interpretations since drag is the water resistance that makes the swimmers’ displacement difficult. Conversely, the drag coefficient is less dependent on speed, which can be seen as a more appropriate measure of the swimmers’ hydrodynamic profile. This study used a complete experimental methodology (experimental and cross-sectional study) to determine the resistive forces in crawl swimming at the same speed (i.e., 1.00, 1.05, 1.10 m/s, etc.). In 10 proficient non-competitive adult swimmers (seven men and three women), the drag coefficient (CD ) was compared and the difference between using the technical drag index (TDI) with drag (D, passive or active) or with its respective CD 's. Measurements of active drag (DA ), passive drag (DP ) and CD (CDA and CDP ) were carried out. The TDI was calculated as a measure of swimming efficiency and the frontal surface area (FSA) obtained in active conditions. The active FSA was 20.73 ± 5.56% greater than the passive FSA (large effect size), the propulsion was 58.29 ± 69.61% greater than drag and CDA was 24.60 ± 46.55% greater than CDP (moderate effect size). TDI was significantly lower, but with a small effect size when measured with CD values compared to drag. TDID vs TDICD revealed strong agreement (> 80% of plots were within IC95). This study concludes that proficient swimmers presented a CDA greater than the CDP, but with strong agreement between them, probably due to FSA during active conditions. CD data appears to be a more absolute indicator of drag than TDI.
- Insights on the Selection of the Coefficient of Variation to Assess Speed Fluctuation in SwimmingPublication . Pinto, Mafalda P.; Marinho, D.A.; Neiva, Henrique P.; Barbosa, Tiago M.; Morais, J.E.The aim of this study was to compare swimming speed and speed fluctuations in front crawl between swimmers of different performance levels using discrete variables against statistical parametric mapping (SPM). The sample was composed of 34 male swimmers divided into three groups: (i) group #1—recreational swimmers; (ii) group #2—competitive swimmers aged 12 to 14 years; (iii) group #3—competitive swimmers aged 15 to 17 years. Swimming speed and speed fluctuations (calculated based on four different conditions) were used as discrete variables. Using these discrete variables, ANOVA one-way was used to verify differences between groups, and Bonferroni post-hoc correction for pairwise comparison whenever suitable. SPM (with similar statistical tests) was used to analyze the swimming speed and fluctuation as a continuous variable. Overall, both statistical approaches revealed significant differences (p < 0.001) in swimming speed and speed fluctuations. However, as discrete variables (in four different conditions), the speed fluctuation was not able to detect significant differences between groups #2 and #3. Conversely, SPM was more sensitive and did yield significant differences between these two groups. Therefore, researchers and coaches should be aware that the speed fluctuation as a discrete variable may not identify differences in swimming speed fluctuations when the average value between groups is marginal. On the other hand, SPM was more sensitive in analyzing all groups.
- Learn-to-swim program in a school context for a twelve-week period enhance aquatic skills and motor coordination in Brazilian childrenPublication . Neiva, Henrique P.; Faíl, Luís B.; Pinto, Mafalda P.; Morais, J.E.; Marinho, D.A.; Moura, Orilda M.This study aimed to verify the effects of 12 weeks of swimming lessons implemented in age school Brazilian children’s aquatic skills and motor coordination. Fifty children aged 6 to 10 years old (mean ± SD: 8.34 ± 1.10 years), participated in one swimming lesson per week provided by the school curriculum. Each child was evaluated for their aquatic skills (17 skills checklist) and motor coordination (Körperkoordinationstest Für Kinder test–KTK) before and after the swimming program. This study showed significant improvements in the sum of scores obtained in swimming skills evaluation (31.40 ± 12.89 vs. 46.90 ± 10.73 points, p < .01, d = 3.38). Large effects were found in water orientation and adjustment at the vertical position, breath control, horizontal buoyancy, body position at ventral, dorsal gliding and at longitudinal rotation, front and back somersaults, leg kicking with breath control, feet-first/head-first entries, autonomy in a deep pool and vertical buoyancy and immersion at deep water. The sum of scores in motor coordination assessment increased from 140.64 ± 41.94 to 175.20 ± 41.39 points (p < .01, d = 1.56). These results showed that 12 weeks of swimming practices, even conditioned by state school context (i.e., once a week), allowed Brazilian children aged 6-10 years old to increase aquatic skills and motor coordination.
- Numerical and experimental methods used to evaluate active drag in swimming: a systematic narrative reviewPublication . Lopes, Tiago J.; Morais, J.E.; Pinto, Mafalda P.; Marinho, D.A.In swimming, it is necessary to understand and identify the main factors that are important to reduce active drag and, consequently, improve the performance of swimmers. However, there is no up-to-date review in the literature clarifying this topic. Thus, a systematic narrative review was performed to update the body of knowledge on active drag in swimming through numerical and experimental methods.
- Relationship between swimming speed, intra-cycle variation of horizontal speed, and Froude efficiency during consecutive stroke cycles in adolescent swimmersPublication . Pinto, Mafalda P.; Marinho, D.A.; Neiva, Henrique P.; Morais, J.E.The purpose of this study was to investigate the relationship between swimming speed, intra-cycle variation of horizontal speed of displacement (dv), and Froude efficiency (ηF) in front-crawl during three consecutive stroke cycles. The sample consisted of 15 boys aged 16.07 ± 0.77 years and 15 girls aged 15.05 ± 1.07 years. Swimming speed, dv and ηF were measured during a 25 m front-crawl trial. Three consecutive stroke cycles were measured. Swimming speed showed a non-significant stroke-by-stroke effect (F = 2.55, p = 0.087, η2 = 0.08), but a significant sex effect (F = 90.46, p < 0.001, η2 = 0.76). The dv and ηF had the same trend as the swimming speed for the stroke-by-stroke effect, but a non-significant sex effect (p > 0.05). The Spearman correlation matrix between swimming speed and dv, and swimming speed and ηF showed non-significant correlations for the three stroke cycles in both sexes. However, the tendency of the former was not always inverse, and the latter was not always direct. Coaches and swimmers need to be aware that lower dvs are not always associated with faster swimming speeds and vice-versa, and that ηF is a predictor of swimming speed, not dv.
- Underwater Struggles: An Approach to Depression, Anxiety, and Burnout in SwimmersPublication . Pinto, Mafalda P.; Costa-Machado, Renato; Neiva, Henrique P.; Morais, J.E.Competitive swimming, often seen as a rigorous sport, has profound impacts in the physical well-being of athletes and on their mental health. It demands high levels of dedication and resilience, which can sometimes lead to psychological challenges such as depression, anxiety, and burnout. This brief review aims to resume on a solid basis the impact of depression, anxiety, and burnout in swimmers. Five studies were analysed. The research sentence was defined ((depression OR anxiety OR burnout) AND (swimmers OR swimming OR swim)) and the search was done considering only title and abstract and publication dates from the past six years. Time of day and sleep quality significantly affect adolescent swimmers' performance, anxiety, and depression, varying by trial distance and sex. Broad, data-driven research is needed to differentiate healthy engagement from maladaptive specialization. Aquatic exercises show mental health benefits, requiring clinician support, confidence, and safety, with seasonal limitations. Moreover, coaches should consider athletes' circadian typology and sleep quality for optimal performance. There is a lack of information regarding mental health in competitor swimmers. Future studies must refine intervention strategies, assess sustainability, and address heterogeneity in findings, as comprehensive, nuanced empirical evidence remains crucial. Apart from the competitive athletes, aquatic exercises appear to benefit mental health, but require clinician support, confidence, and safety considerations. Time of day and sleep quality impact adolescent swimmers' performance and mental health, differing by trial distance and sex. There is a need for information to truly understand the difference between healthy engagement and maladaptive specialization.
- Using wearables to monitor swimmers’ propulsive force to get real-time feedback and understand its relationship to swimming velocityPublication . Lopes, Tiago J.; Sampaio, Tatiana; Oliveira, João P.; Pinto, Mafalda P.; Marinho, D.A.; Morais, J.E.Evidence on the role of propulsion compared to drag in swimming, based on experimental settings, is still lacking. However, higher levels of propulsion seem to lead to faster swimming veloci- ties. The aim of this study was to understand the variation in a set of kinematic and kinetic variables between two swimming sections and their relationship to swimming velocity. The sample consisted of 15 young adult recreational swimmers (8 males: 20.84 ± 2.03 years; 7 females: 20.13 ± 1.90 years). Maximum swimming velocity and a set of kinematic and kinetic variables were measured during two consecutive sections of the swimming pool. Differences between sections were measured and the determinants of swimming velocity were analyzed. Swimming velocity, propulsive force, and the other kinematic and kinetic variables did not change significantly (p < 0.05) between sections (only the intra-cyclic fluctuation of swimming velocity decreased significantly, p = 0.005). The modeling identified the propulsive force, stroke length, and active drag coefficient as the determinants of swimming velocity. Swimming velocity was determined by the interaction of kinematic and kinetic variables, specifically propulsive force and active drag coefficient