Percorrer por autor "Moriyama, Shin-Ichiro"
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- Assisted towing does not affect arm stroke coordination in front-crawl swimmingPublication . Moriyama, Shin-Ichiro; Watanabe, Yasunori; Toyoda, Yugo; Hamamichi, Takeru; Morais, J.E.; Neiva, Henrique P.; Forte, Pedro; Marinho, D.A.This study clarified changes in arm stroke coordination during assisted swimming. Fourteen male collegiate swimmers swam with and without an assist at a maximum effort.
- Comparison of swimming velocity between age-group swimmers through discrete variables and continuous variables by Statistical Parametric MappingPublication . Morais, J.E.; Barbosa, Tiago M.; Lopes, Tiago J.; Moriyama, Shin-Ichiro; Marinho, D.A.The aim of this study was to compare the swimming velocity in frontcrawl between age-group swimmers using discrete variables against Statistical Parametric Mapping (SPM). The sample consisted of 30 young male swimmers divided into three groups (each with 10 swimmers) based on their age (group #1: 13.60 ± 0.84 years; group #2: 15.40 ± 0.32 years; group 3: 16.39 ± 0.69 years). Swimmers performed three maximal trials in front-crawl. The best performance was used for analysis. Comparison of swimming velocity between groups was analysed using discrete variables and as a continuous variable (SPM). As a discrete variable, the mean swimming velocity showed a significant difference between groups (p < 0.05). Moreover, when analysed by SPM, swimming velocity showed a significant difference (p = 0.021) between the ~ 44% and ~ 51% of the stroke cycle (transition of the propulsion phases between sides). Post-hoc comparison revealed a significant difference between group #1 and group #3 only in SPM analysis. Researchers, coaches, and practitioners should know that both measurement approaches can be used simultaneously. However, SPM offers more sensitive and accurate results about the swimmers’ stroke cycle.
- Effect of additional buoyancy swimsuits on performance of competitive swimmersPublication . Moriyama, Shin-Ichiro; Watanabe, Yasunori; Kurono, Tsubasa; Morais, J.E.; Marinho, D.A.; Wakayoshi, KohjiWhen in water, the Centers of Buoyancy (CoB) and Mass (CoM) of the human body are positioned cranially and caudally, respectively. With increasing distance between these centers, the sinking torque of the lower limbs increases, with a subsequent decrease in swimming performance due to increased drag. Objective: To clarify the effect of additional buoyancy swimsuits on swimming performance. Methods: The subjects were eight competitive male swimmers of mean ±SD age 21±2 years. Swimming performance was compared between Conventional (CS) and Additional Buoyancy Swimsuits (ABS). CoM and CoB were identified on land and in water, respectively, with the swimmers maintaining a horizontal posture. CoM was measured by the reaction board method. CoB was calculated as the force exerted in the vertical direction accompanied by changes in inspiratory volume. Swimming velocity and Blood Lactate (BL) concentration value during 200 m front crawl in trials at four different speeds (curve test) were recorded as swimming performance. Results: No significant difference in inspiratory volume was observed between CS and ABS (small effect size, d=0.28). The distance between CoM and CoB was significantly shorter for CS than ABS (p < 0.001; large effect size, d=1.08). Both swimming velocity at BL of 4 mmol·L-1 and maximal effort were significantly faster for ABS (p < 0.042; 0.008), with large effect size (d=0.91; 0.98). However, there was no significant difference in maximal BL between CS and ABS (small effect size, d=0.37).
- Effect of resisted sled sprint with different loads on running velocity, step frequency, and step length in trained collegiate track and field athletesPublication . Hamamichi, Takeru; Noi, Kiyotaka; Shigeta, Susumu; Morais, J.E.; Marinho, D.A.; Moriyama, Shin-IchiroResisted sled sprint (RSS) is a traditional sprint training in which a variety of loads are used for multiple aims. Nevertheless, a detailed analysis of the effects of different loads has not yet been performed. Therefore, this study aimed to examine the effects of load differences on running velocity, step frequency, and step length during RSS in trained collegiate track and field athletes. Twenty-one collegiate track and field male athletes (20.6±1.3 years) performed eight 60-m sprints with and without a resisted sled. The sled loads were individually set based on the participant's body mass (BM) and were applied in 10% increments from 20% to 80% of BM. The running distance was divided into six 10-m phases. The mean running velocity, step frequency and step length at each phase, and interactions in each were analysed. All indices decreased with increasing loads. Significant differences were observed in running velocity and step frequency between all loads, except between 70% and 80% of BM, and in the step length between all loads. The maximum values for the variables appeared in different phases according to the load. These results suggested that athletes and coaches should consider that sprinting performance during RSS varies with load.
- Effects of implementating a hybrid teaching model in a basketball didactic unitPublication . Ferraz, Ricardo; Oliveira, Julio; Alves, Ana Ruivo; Forte, Pedro; Teixeira, José Eduardo; Moriyama, Shin-Ichiro; Valente, Nelson; Branquinho, LuísThe eminent purpose of physical education (PE) is to promote physical fitness, health, and overall well-being among individuals. It aims to develop motor skills, improve cognitive functions, and instill a lifelong appreciation for an active and healthy lifestyle. Physical education also fosters social skills, teamwork, and discipline, contributing to the holistic development of individuals. The study aimed to assess the impact of a hybrid teaching model, integrating elements from the Sport Education Model (SEM) and Teaching Games for Understanding (TGfU), on the performance and motivation of students during basketball lessons. Eighteen adolescents (9 girls and 8 boys) aged 15-17 years (mean ± SD: 15.67 ± 0.69 years) participated in the study. Participants engaged in basketball physical education classes twice a week, incorporating principles and attributes from both TGfU and SEM. Motivation and performance (GP) were evaluated before and after basketball sessions. The students' motivation was assessed using the Attitude Questionnaire of Students towards PE, and the performance was measured using the Game Performance Assessment Instrument. The results showed significant improvements in students' GP, but no differences in motivation was found at the end of the instructional unit. However, it was discovered that students enjoyed and appreciated physical education (PE), demonstrating a favorable attitude towards the subject. A hybrid teaching model with principles based on TGfU and SEM seems to be an appropriate approach to enhance students' game understanding, decision-making and overall GP (game skills, both technical and tactical). Attributes and principles such as simulating a sports season and student-centered learning situations that consider individual needs, seems to be important to develop students' awareness of attributing meaning to their actions, resulting in improved GP. The findings could be useful to teachers, coaches and researchers contributing to the development of teaching strategies to empower the PE classes.
- How does 11-week detraining affect 11-12 years old swimmers’ biomechanical determinants and its relationship with 100 m freestyle performance?Publication . Morais, J.E.; Lopes, Vitor P.; Barbosa, Tiago M.; Moriyama, Shin-Ichiro; Marinho, D.A.The aim of this study was to analyse the detraining process that occurs during a season break, and its influence on the performance, anthropometrics, and biomechanics of young swimmers. The sample included 54 young swimmers (22 boys: 12.79 +/- 0.71 years; 32 girls: 11.78 +/- 0.85 years). Performance for the 100 m freestyle and anthropometric and biomechanical variables were evaluated as main determinants. Performance impaired significantly for boys (2.17%) and girls (1.91%). All anthropometric variables increased between moments of assessment for boys and girls. Overall, the boys enhanced all biomechanical variables during the detraining period, and girls showed mixed results. For both sexes, the stroke index was the variable with the highest increase (boys: Delta = 16.16%; d = 0.89; p = 0.001; girls: Delta = 19.51%; d = 1.06; p = 0.002). Hierarchical linear modelling showed that the height retained the amount of impairment in the performance. One unit of increase in the height (cm) led to less 0.41 s impairment in the performance. Present data indicated that during an 11-weeks detraining period, young swimmers impaired their performance, but the determinant factors showed an impaired relationship. This increase in the determinant factors is mainly related to the increase in the swimmers' anthropometrics. Moreover, the increase in height was responsible for retaining the performance impairment.
- Swimming speed comparison between two distinct arm pulls during the butterfly swim strokePublication . Morais, J.E.; Marinho, D.A.; Neiva, Henrique P.; Moriyama, Shin-Ichiro; Barbosa, Tiago M.The aim of this study was to compare the butterfly swimming speed during the insweep phase of two distinct arm pull patterns. Ten national-level swimmers (5 males with 17.5 ±0.8-years and 5 females with 16.8±0.9-years) were analyzed while performing butterfly all-out trials based on two distinct arm-pull patterns (“bent” and “straight”). The “bent” armpull refers to the stroke kinematics they use to swim. The “straight” arm-pull refers to a more extended elbow than they used to swim. Based on discrete variables, swimming speed was faster in the “straight” than the “bent” arm-pull, but not significantly (p=0.546). Non-significant differences were also noted for the remaining discrete variables. Conversely, Statistical Parametric Mapping (SPM, continuous analysis) identified significant differences in swimming speed between ∼42% and ∼60% (insweep phase and the beginning of the upsweep phase; p=0.001), and ∼83% and ∼87% (halfway through the release and recovery, respectively; p=0.043) of the stroke cycle. SPM was more sensitive in identifying differences in swimming speed between arm pulls. Swimmers were faster while performing the “straight” arm pull than with the “bent” arm pull, predominately based on a faster swimming speed during the insweep phase.
- The effect of the start and finish in the 50 m and 100 m freestyle performance in elite male swimmersPublication . Marinho, D.A.; Barbosa, Tiago M.; Neiva, Henrique P.; Moriyama, Shin-Ichiro; Silva, A.J.; Morais, J.E.The aim of this study was to: (1) verify differences between swimmers of the same competitive level in variables related to the start and finish (50 m and 100 m freestyle); (2) verify if starting and finish variables are responsible for faster race time, and which starting variables are responsible for the start performance in such events. For the 50 m and 100 m freestyle race at the junior European Championships 2019, 86 and 88 male swimmers were analysed, respectively. A set of starting and finishing variables were used for analysis. Both races (50 m: p < 0.001; 100 m: p < 0.001) presented a significant level effect for the final race time. The same trend was observed for the start and finish performances. For both races, hierarchical linear modelling retained the 15 m mark time and finish speed as predictors. The 50 m start retained the reaction time and underwater speed, and the 100 m start retained the reaction time and the water break distance. This indicates the underwater phase of the start is of substantial importance to improve the 15 m mark time. Coaches and swimmers are advised to enhance the start underwater phase, and finish segments to improve the swimmers’ performance.
- The impact of assisted swimming on front crawl performancePublication . Moriyama, Shin-Ichiro; Watanabe, Yasunori; Masuda, Kosuke; Toyoda, Yugo; Morais, J.E.; Forte, Pedro; Neiva, Henrique P.; Marinho, D.A.In the present study, we aimed to clarify the impact of the Assisted swim (A-swim; towing from propulsion direction) on front crawl performance at maximum and sub-maximum effort levels. Methods: Fourteen male collegiate swimmers (age, 21.0 ± 2.0 years; height, 1.73 ± 0.05 m; weight, 67.1 ± 7.1 kg) participated. Participants swam 25-m front crawl at maximal (Max) and submaximal intensity (Submax (80% of the max stroke rate (SR))) with and without an assist (assisted swimming with a towing device and normal swim (N-swim) without the device) for a total of four lengths. In addition to swim velocity (V), SR, and stroke length (SL), one stroke cycle was broken down into four phases—glide, pull, push, and recovery—and analyzed the duration of each phase. Results: A significant interaction of level of efforts and presence/absence of towing was confirmed in V, SR, and SL. V and SL showed a significant increase in A-swim compared to N-swim at both Max and Submax. SR was significantly higher in A-swim than in N-swim only at Max. Each phase of stroke showed a significant difference in recovery at Submax and push at Max. Conclusions: Despite considering the impact of propulsion from towing, A-swim increased SR, in addition to the V and SL, of swimmers compared with N-swim.