Browsing by Author "Marinho, Daniel A."
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- Aerodynamics of a wheelchair sprinter racing at the 100m world record pace by CFDPublication . Forte, Pedro; Marinho, Daniel A.; Morais, Jorge E.; Morouço, Pedro; Pascoal-Faria, Paula; Barbosa, Tiago M.The aim of this study was to analyze aerodynamics in a racing position of a wheelchair-racing sprinter, at the world record speed. The athlete and wheelchair were scanned at the beginning of the propulsive phase position (hands near the handrims at 12h) for the 3D model acquisition. Numerical simulation was run on Fluent, having as output the pressure, viscosity and total drag force, and respective coefficients of drag at the world record speed in T-52 category. Total drag was 7.56N and coefficient of drag was 1.65. This work helped on getting a deeper insight about the aerodynamic profile of a wheelchair-racing athlete, at a 100m world record speed.
- Associations between partial times and total time in 50 m front crawl, according to agePublication . Amaro, Nuno; Dias, Pedro; Marques, Mário C.; Marinho, Daniel A.; Morouço, Pedro
- Basic psychological needs and subjective well-being in Portuguese older peoplePublication . Couto, Nuno; Antunes, Raul; Monteiro, Diogo; Moutão, João; Marinho, Daniel A.; Cid, LuísThe aim of this study is the validation of the Portuguese version of the Basic Need Satisfaction General Scale (BNSG-S) in a sample of Portuguese elderly, and analyze through a structural equations model the effect of the Portuguese elderly individuals’ global perception about the satisfaction of basic psychological needs on subjective well-being. Two samples of Portuguese elderly people aged between 60 and 90 years old were considered in this study. Results revealed that they Model 3 of the BNSG-S (three factors, 11 items) adjusted to the data a (Χ2 = 103.16, df = 41, SRMR =. 05, TLI =. 90, CFI =. 93, RMSEA =. 07, 90% CI =. 05-.08). Additionally, structural model analysis, showed a positive and significant effect between satisfaction of basic psychological needs and subjective well-being. In sum we concluded that the Portuguese version of the BNSG-S can be used as a means to evaluate the satisfaction of the basic psychological needs of the older population and, their satisfaction, has a positive effect on subjective well-being in the Portuguese older population.
- Biomechanical and bioenergetical evaluation of swimmers using fully-tethered swimming: A qualitative reviewPublication . Amado, Nuno M.; Morouço, Pedro, G.; Marques, Mário C.; Fernandes, Ricardo J.; Marinho, Daniel A.It is presented a qualitative review of the specialized literature on fully-tethered swimming, with the scopes of summarizing and highlighting published knowledge, identifying its gaps and limitations, and motivate future research. The major research conclusions can be summarized as follows: (i) tethered swimming is a reliable test to evaluate force exerted in water by swimmers; (ii) higher maximum values of force are obtained in breaststroke and butterfly, while average values are higher in front crawl; (iii) tethered forces present moderate to strong relationships with swimming velocity, and associations between forces diminish as swimming distance increases; (iv) 30 s maximal tethered swimming may be used as an adaptation of Wingate test for swimming; (v) differences in stroke mechanics can occur in tethered swimming but there is no evidence to suggest that they affect swimming performance; (vi) Tethered swimming is a valid methodology to evaluate aerobic energy contribution in swimming and recent investigations concluded that it can also provide information on the anaerobic contribution. Based on and stimulated by current knowledge, further research should focus on the following topics: (i) the usefulness of tethered swimming as a valid tool to evaluate other swimming techniques; (ii) differences in force parameters induced by gender or competitive level; (iii) defining accurate variables for estimation of anaerobic power and/or capacity using tethered swimming; (iv) bilateral asymmetries in exerted forces, and corresponding influence of breathing; (v) relative contribution of arms and legs for whole-body propelling forces
- CFD analysis of head and helmet aerodynamic drag to wheelchair racingPublication . Forte, Pedro; Marinho, Daniel A.; Morouço, Pedro; Barbosa, TiagoWheelchair racing, an important event in Paralympics, it requires huge effort from its athletes to overcome the resistive forces. The resistive forces in wheelchair racing are aerodynamic drag and rolling friction. CFD methodology can play a determinant role in aerodynamic analysis. The aim of this study was to analyses the aerodynamic drag at different speeds and attack angles of a human head with a helmet, whilst extrapolating results to better suit the needs of wheelchair racing athletes. Computer Fluid Dynamics methodology was used in this study. A 3D head and helmet scan was obtained from a Paralympics athlete. The 3D model was exported to fluent software generating the aerodynamic drag after numerical simulation. Regardless the velocity, 90° attack angle (subject looking down) presented higher aerodynamic drag (0.732 N) Wheelchair racing athletes should maintain a 0° attack angle (looking forward) mainly at speeds greater than 3.5 m/s.
- Differences in swimming force metrics induced by genderPublication . Amaro, Nuno; Morouço, Pedro; Marinho, Daniel A.
- Efeito de um treino de força em seco no desempenho em jovens nadadoresPublication . Amaro, Nuno; Marinho, Daniel A.; Marques, Mário C.; Batalha, Nuno; Morouço, PedroEm natação a performance depende da força e potência muscular (Newton et al., 2002) e a capacidade de exercer força na água é fundamental, especialmente em distâncias curtas (Morouço et al., 2011). Assim, os programas de treino de força em seco são comuns em natação ainda que o consenso sobre os benefícios específicos para o nadador ainda não tenha sido alcançado (Tanaka et al., 1993; Trappe and Pearson, 1994; Girold et al., 2007). Por um lado, várias investigações apresentaram melhorias na performance de nado após um programa de treino de força em seco (Strass, 1988; Girold et al., 2007; Aspenes et al., 2009; Girold et al., 2012). Por outro lado, várias investigações não apresentaram melhorias na performance de nado após um programa de treino de força em seco (Tanaka et al., 1993; Trappe and Pearson, 1994; Garrido et al., 2010; Sadowski et al., 2012). As razões para os resultados menos positivos podem dever-se a falhas nos protocolos de intervenção, tais como: especificidade do meio aquático (incapacidade de replicar os movimentos aquáticos em meio terrestre e a falta da resistência da água); escolha de exercícios pouco específicos ou que não solicitem os mesmos grupos musculares que o nado; velocidade de execução e cargas dos exercícios; amostra e os momentos das avaliações. As investigações com jovens nadadores são ainda mais escassas do que com adultos, o que revela alguma necessidade de investigação em torno deste assunto. Assim, os objetivos deste estudo foram examinar os efeitos de um programa de treino de força em seco: (i) na performance de nado e (ii) produção de força na água.
- Effects of different protocols of physical exercise on fibromyalgia syndrome treatment: systematic review and meta-analysis of randomized controlled trialsPublication . Albuquerque, Maria Luiza L.; Monteiro, Diogo; Marinho, Daniel A.; Vilarino, Guilherme T.; Andrade, Alexandro; Neiva, Henrique P.Physical exercise has been used as a form of treatment for fbromyalgia, however, the results indicate the need for further investigations on the efect of exercise on diferent symptoms. The aim of the study was to synthesize and analyse studies related to the efect of exercise in individuals with fbromyalgia and provide practical recommendations for practitioners and exercise professionals. A search was carried out in the Web of Science, PubMed, and Scopus databases in search of randomized clinical trials (RCT) written in English. A meta-analysis was performed to determine the efectiveness of different types of exercise on the fbromyalgia impact questionnaire (FIQ), and the protocol period and session duration on the pain outcome. Eighteen articles were eligible for a qualitative assessment and 16 were included in the meta-analysis. The exercise showed large evidence for the association with a reduction in the FIQ (SMD −0.98; 95% CI −1.49 to −0.48). Protocols between 13 and 24 weeks (SMD −1.02; 95% CI −1.53 to −0.50), with a session time of less than 30 min (SMD −0.68 95% CI −1.26 to −0.11) or>30 min and<60 min (SMD −1.06; 95% CI −1.58 to −0.53) presented better results. Better results were found after combined training protocols and aerobic exercises. It is suggested that exercise programs lasting 13–24 weeks should be used to reduce pain, and each session should last between 30 and 60 min. In addition, the intensity should always be carried out gradually and progressively
- Effects of Dry-Land Strength and Conditioning Programs in Age Group SwimmersPublication . Amaro, Nuno M.; Marinho, Daniel A.; Marques, Mário C.; Batalha, Nuno P.; Morouço, Pedro G.Amaro, NM, Marinho, DA, Marques, MC, Batalha, N, and Morouc¸o, PG. Effects of dry-land strength and conditioning programs in age group swimmers. J Strength Cond Res 31(9): 2447–2454, 2017 —Even though dry-land S&C training is a common practice in the context of swimming, there are countless uncertainties over its effects in performance of age group swimmers. The objective was to investigate the effects of dry-land S&C programs in swim ming performance of age group swimmers. A total of 21 male competitive swimmers (12.7 6 0.7 years) were randomly assigned to the Control group (n = 7) and experimental groups GR1 and GR2 (n = 7 for each group). Control group performed a 10-week training period of swim training alone, GR1 followed a 6-week dry land S&C program based on sets and repetitions plus a 4-week swim training program alone and GR2 followed a 6-week dry-land S&C program focused on explosiveness, plus a 4-week program of swim training alone. Results for the dry-land tests showed a time effect between week 0 and week 6 for vertical jump (p , 0.01) in both experimental groups, and for the GR2 ball throwing (p , 0.01), with moderate to strong effect sizes. The time 3 group analyses showed that for performance in 50 m, differences were significant, with the GR2 presenting higher improvements than their counterparts (F = 4.156; p = 0.007; h2 p = 0.316) at week 10. Concluding, the results suggest that 6 weeks of a complemen tary dry-land S&C training may lead to improvements in dry-land strength. Furthermore, a 4-week adaptation period was mandatory to achieve beneficial transfer for aquatic performance. Additional benefits may occur if coaches plan the dry-land S&C training focusing on explosiveness.
- Estimation of an Elite Road Cyclist Performance in Different Positions Based on Numerical Simulations and Analytical ProceduresPublication . Forte, Pedro; Marinho, Daniel A.; Barbosa, Tiago M.; Morouço, Pedro; Morais, Jorge E.The aim of this study was to use numerical simulations and analytical procedures to compare a cyclist's performance in three different cycling positions. An elite level road cyclist competing at a national level was recruited for this research. The bicycle was 7 kg and the cyclist 55 kg. A 3D scan was taken of the subject on the competition bicycle, wearing race gear and helmet in the upright position, in the handlebar drops (dropped position) and leaning on the elbows (elbows position). Numerical simulations by computer fluid dynamics in Fluent CFD code assessed the coefficient of drag at 11.11 m/s. Following that, a set of assumptions were employed to assess cycling performance from 1 to 22 m/s. Drag values ranged between 0.16 and 99.51 N across the different speeds and positions. The cyclist mechanical power in the elbows position differed from the upright position between 0 and 23% and from the dropped position from 0 to 21%. The cyclist's energy cost in the upright position differed 2 to 16% in comparison to the elbows position and the elbows position had less 2 to 14% energy cost in comparison to the dropped position. The estimated time of arrival was computed for a 220,000 m distance and it varied between 7,715.03 s (2 h:8 min:24 s) and 220,000 s (61 h:6 min:40 s) across the different speeds and positions. In the elbows position, is expected that a cyclist may improve the winning time up to 23% in comparison to he upright and dropped position across the studied speeds.