Relationship between oxygen uptake reserve and heart rate reserve in young male tennis players: implications for physical fitness monitoring

The aims of this study were to (i) verify the relationship between reserve oxygen uptake (VOreserve) and reserve heart rate (HRreserve) in young male tennis players, and (ii) understand the relationship between oxygen uptake (VO2) measured at the end of a tennis drill and recovery heart rate (HRrecovery) after the tennis drill. Ten young male tennis players (16.64 1.69 years; 62.36 6.53 kg of body mass; 175.91 5.26 cm of height) were recruited from the National Tennis Association. Players were instructed to perform a tennis drill based on an incremental intensity protocol. Afterward, three levels of intensity were used based on VO2reserve and HRreserve. A significant variance was observed between levels (VO2reserve and HRreserve = p < 0.001). VO2reserve presented a significant and high agreement with HRreserve. The mean data revealed non-significant differences (p > 0.05), a very high relationship of linear regression (R2 = 82.4%, p < 0.001), and high agreement in Bland Altman plots. VO2, at the highest level of intensity (>93%), presented a significant correlation with HRrecovery during the immediate 30 s after the drill (rs = 0.468, p = 0.028). Tennis coaches or instructors must be aware of the differences between monitoring or prescribing training intensities based on HRreserve or HRmax. They can also use HRrecovery for 30 s immediately after exercise to verify and understand the variation in their players’ cardiorespiratory capacities.This research was funded by the Portuguese Foundation for Science and Technology (FCT) under the grant number UIDB/DTP/04045/2020info:eu-repo/semantics/publishedVersio

A Theoretical Contribution To Improve The Formation In The Historical Lisbon School Of Architecture - The Forgotten Dimension of the Technological Perspective

This article approaches the problem of the absence of the technology in the didactics of the Architecture´s Design, in the course of School of Architecture of Lisbon, as the subtitle of the article suggests - the forgotten dimension of the technological perspective.Despite of the course contemplates a relevant technological component, however, does not reflect, much less exponent the creative act of the Project. This is first of all a result of the organization, didactics and contents of the Project classes, and not so much, a lack of knowledge provided to the student in the technological disciplines, which are present in quantity in the curricular structure. The situation, analyzed in this article, is a consequence of a blocking of the Project classes to the technology ones, which do not promote, nor allow, the necessary transdisciplinary articulation and integration between the act of designing and the application of technological knowledge, which is fundamental and intrinsic to the act of thinking and conceiving Architecture.The CAD / CAE / CAM digital tools have not only highlighted the fragility of this didactic process in the didactic context of the current teaching, but, in view of the potential of its operative process, impose the future reformulation of the Project's cognitive practice, integrating the component technology in the Design Methodology of the architect's teaching and praxisN/

Development of a metric of aquatic invertebrates for volunteers (MAIV): a simple and friendly biotic metric to assess ecological quality of streams

Citizen science activities, involving local people in volunteer-supported and sustainable monitoring programs, are common. In this context, the objective of the present work was to develop a simple Metric of Aquatic Invertebrates for Volunteers (MAIV), including a user-friendly tool that can be easily accessed by volunteers, and to evaluate the e ciency of a volunteer monitoring program following an audit procedure. To obtain MAIV values, macroinvertebrate communities were reduced to 18 surrogate taxa, which represented an acceptable compromise between simplicity, e ciency, and reproducibility of the data, compared to the regular Water Framework Directive monitoring. When compared to results obtained with the National Classification System of Portugal, MAIV accurately detected moderate, poor, and bad ecological status. Thus, MAIV can be used by volunteers as a complement to the o cial monitoring program, as well as a prospective early warning tool for local problems related to ecological quality. Volunteers were students supervised by their teachers. Results obtained by volunteers were compared to results obtained by experts on macroinvertebrate identification to measure the e ciency of the procedure, by counting gains and losses on sorting, and identification. Characteristics of groups of volunteers (age and school level) did not influence significantly the e ciency of the procedure, and generally results of volunteers and experts matched.info:eu-repo/semantics/publishedVersio

Isolation by distance, not rivers, control the distribution of termite species in the Amazonian rain forest

The spatial distribution of species is affected by dispersal barriers, local environmental conditions and climate. However, the effect of species dispersal and their adaptation to the environment across geographic scales is poorly understood. To investigate the distribution of species from local to broad geographic scales, we sampled termites in 198 transects distributed in 13 sampling grids in the Brazilian Amazonian forest. The sampling grids encompassed an area of 271 500 km2 and included the five major biogeographic regions delimited by Amazonian rivers. Environmental data for each transect were obtained from local measurements and remote sensing. Similar to previous studies, termite species composition at the local scale was mostly associated with measures of soil texture and chemistry. In contrast, termite species composition at broad geographic scales was associated with soil nutrients, and the geographic position of the transects. Between 17 and 30% of the variance in termite species composition could be attributed exclusively to the geographic position of the transects, but could not be attributed to measured environmental variables or the presence of major rivers. Isolation by distance may have strong effects on termite species composition due to historic processes and the spatially structured environments along distinct geological formations of Amazonia. However, in contrast to many taxa in Amazonia, there is no evidence that major rivers are important barriers to termite dispersal

Interaction of kinematic, kinetic, and energetic predictors of young swimmers’ speed

The aim of this study was to assess the interaction of kinematic, kinetic, and energetic variables as speed predictors in adolescent swimmers in the front-crawl stroke. Design: Ten boys (mean age [SD] = 16.4 [0.7] y) and 13 girls (mean age [SD] = 14.9 [0.9] y) were assessed. Methods: The swimming performance indicator was a 25-m sprint. A set of kinematic, kinetic (hydrodynamic and propulsion), and energetic variables was established as a key predictor of swimming performance. Multilevel software was used to model the maximum swimming speed. Results: The final model identified time (estimate = −0.008, P = .044), stroke frequency (estimate = 0.718, P < .001), active drag coefficient (estimate = −0.330, P = .004), lactate concentration (estimate = 0.019, P < .001), and critical speed (estimate = −0.150, P = .035) as significant predictors. Therefore, the interaction of kinematic, hydrodynamic, and energetic variables seems to be the main predictor of speed in adolescent swimmers. Conclusions: Coaches and practitioners should be aware that improvements in isolated variables may not translate into faster swimming speed. A multilevel evaluation may be required for a more effective assessment of the prediction of swimming speed based on several key variables rather than a single analysisThis work is supported by national funds (FCT–Portuguese Foundation for Science and Technology) under the project UIDB/DTP/04045/2020.info:eu-repo/semantics/publishedVersio

Race Analysis and Determination of Stroke Frequency: Stroke Length Combinations during the 50-M Freestyle Event

The aims of this study were to: (1) analyze and compare the stroke kinematics between junior and senior elite male swimmers in every section of the race during the 50-m freestyle event, and; (2) identify stroke frequency (SF)–stroke length (SL) combinations on swim speed independently for junior and senior swimmers in each section of the 50-m freestyle event. Eighty-six junior swim- mers (2019) and 95 seniors (2021) competing in the 50-m long course meter LEN Championships were analyzed. The t-test in- dependent samples (p ≤ 0.05) were used to compare juniors and seniors. The SF and SL combinations on swim speed were ex- plored using three-way ANOVAs. Senior swimmers were signif- icantly faster in the 50-m race than juniors (p < 0.001). Speed presented the largest significant difference (p < 0.001) in section S0-15 m (start until the 15th meter mark) being seniors fastest. Both junior and senior swimmers revealed a significant categori- zation (p < 0.001) by stroke length and stroke frequency in each race section. It was possible to model several SF–SL combina- tions for seniors and juniors in each section. The fastest swim speed in each section, for seniors and juniors independently, was achieved by a SF–SL combination that may not be the fastest SF or the longest SL. Coaches and swimmers must be aware that de- spite the 50-m event being an all-out bout, several SF–SL combi- nations were observed (independently for juniors and seniors), and they differ between race sections.This work is supported by national funds (FCT - Portuguese Foundation for Science and Technology) under the project UIDB/DTP/04045/2020.info:eu-repo/semantics/publishedVersio

Aerodynamic analysis of human walking, running and sprinting by numerical simulations

The drag in walking, running, and sprinting locomotion can be assessed by analytical procedures and experimental techniques. However, assessing the drag variations by these three main locomotion’s (i.e., walking, running, and sprinting) were not found using computational fluid dynamics. (CFD). Thus, the aim of this study was two-fold: (1) to assess the aerodynamics of human walking, running, and sprinting by CFD technique; 2) compare such aerodynamic characteristics between walking and running. Three 3D models were produced depicting the walking, running, and sprinting locomotion techniques, converted to computer aided design models and meshed. The drag varied with 4 locomotion type. Walking had the lowest drag, followed-up by running and then sprinting. At the same velocities, the drag was larger in walking than in running and increased with velocity. In conclusion, drag varied with locomotion type. Walking had the lowest drag, followed-up by running and then sprinting. At the same velocities, the drag was larger in walking than in running and increased with velocity.This project was founded by the Portuguese Foundation for Science and Technology, I.P. (project UIDB04045/2020)info:eu-repo/semantics/publishedVersio

Stability analysis and prediction of pacing in elite 1500 m freestyle male swimmers

This study aimed to analyse the stability of elite male long-distance swimmers (1500 m), and to identify the main predictors related to the pace. The performance of 16 elite male swimmers (22.59 ± 2.10 years-old) participating in the 1500 m event at the 2016 (London) and 2018 (Glasgow) LEN European Aquatic Championships were analysed. The lap performance, clean swim performance, turn performance, and a set of stroke mechanics variables were assessed. The lap performance presented a significant and moderate variation with all laps included (p < 0.001) and deleting the first and last lap (p = 0.002). Swimmers were significantly faster in the first half in comparison of the second. The total turn also presented a significant and moderate variation. The hierarchical linear modelling retained the time (estimate = 0.0019, p = 0.007), stroke frequency (estimate = -27.49, p < 0.001) and stroke length (estimate = -6.55, p < 0.001) as the main predictors of the clean swim performance. By contrast to the analysis based on the lap performance, clean swim performance presented a non-significant variation. Coaches should be aware that stroke length maintenance could negatively affect the clean swim performance, whereas a small increase of stroke frequency may present a meaningful enhancement of the total race time.This project was supported by the National Funds through FCT - Portuguese Foundation for Science and Technology [UIDB/DTP/04045/2020]info:eu-repo/semantics/publishedVersio

Non-Newtonian fluid flow through three-dimensional disordered porous media

We investigate the flow of various non-Newtonian fluids through three-dimensional disordered porous media by direct numerical simulation of momentum transport and continuity equations. Remarkably, our results for power-law (PL) fluids indicate that the flow, when quantified in terms of a properly modified permeability-like index and Reynolds number, can be successfully described by a single (universal) curve over a broad range of Reynolds conditions and power-law exponents. We also study the flow behavior of Bingham fluids described in terms of the Herschel-Bulkley model. In this case, our simulations reveal that the interplay of ({\it i}) the disordered geometry of the pore space, ({\it ii}) the fluid rheological properties, and ({\it iii}) the inertial effects on the flow is responsible for a substantial enhancement of the macroscopic hydraulic conductance of the system at intermediate Reynolds conditions. This anomalous condition of ``enhanced transport'' represents a novel feature for flow in porous materials.Comment: 5 pages, 5 figures. This article appears also in Physical Review Letters 103 194502 (2009