Interactional response during infants’ aquatic sessions

The aim of study was to assess infants’ behaviour during routine swimming sessions using a naturalistic observation method. The study sample included 14 infants (13.7 ± 7.5 months old) with previous aquatic experience. The frequency of occurrences per unit of time (session) in the different dimensions – infant’s motor behaviour and social-affective interaction – was registered over the course of two sessions by two independent experts. The behaviours most frequently observed were accompanied displacement (61.1 %) and interaction with others (41.6 %). Submersions or jumps represented only 8.4 % of the session. Implementing a child-centred methodology leads to positive behaviours during this type of sessions, contributing to the child’s healthy development.info:eu-repo/semantics/publishedVersio

Influence of sociological aspects on the level of physical activity in physical education students

Adopting and maintaining an active lifestyle for adolescent students, seems to be impaired and influenced by several factors, among them stand out environmental, psychological and social factors. Thus, the general objectives of this study were submitted to study and understand the extent to which these environmental, social and personal factors help and influence the level of physical activity (PA) by the adolescents in school age. More specifically, we will study: (1) the possible association between level of physical activity, age and gender; (2) consider and determine whether there is an association between socioeconomic variables and physical activity level of the population sample; (3) assess on the possible association between environmental variables and perceived physical activity of the adolescents. The sample consisted of 286 high school students, male gender (n = 125) and female (n = 161) aged between 15 and 18 years of age. As an instrument of study, a questionnaire was used. The main results of this study demonstrate a possible relationship between gender and level of PA, while boys tend to be more active than girls and also an association between socioeconomic variables and level of physical activity

Longitudinal study of physical fitness levels, BMI and childhood obesity in school context

This work is aimed at knowing the level of physical aptitude and its degree of association, regarding an urban and a rural area, in children from the primary education schools. The sample consisted of six schools from the primary education of the county of Fundão: Santa Teresinha school (a central school), and the schools of Valverde, Fatela, Enxames, Alcaria and Peroviseu (peripheral schools). The sample has been selected in order to have a certain number of pupils from a peripheral area and another one from a central area of the city. The total sample is represented by 161 pupils, 76 are female and 85 are male and they are aged between 6 and 10. 85 come from an urban area and 76 come from a rural area. The analysis of the physical aptitude had as a reference the battery Prudential Fitnessgram (2002). According to the results obtained in the anthropometry, boys and girls from rural areas are heavier and taller than the boys and girls from urban areas. Regarding the BMI and body fat, it is males in rural areas that show a higher number of pupils in the healthy zone. As far as females are concerned, it is the urban area that has more pupils in that zone. It was also noticed that there are a huge percentage of girls from the rural area in the thin zone. In the differentiation between genders, boys have better results in physical aptitude and obesity levels. Regarding the influence of the living area, there are obviously better results in the urban area than in the rural area. Our study reveals that there are significant differences in the physical aptitude tests when they were applied at two different moments. After the analysis and interpretation of the results, we can conclude that boys and girls coming from rural areas are taller and heavier than the ones from urban areas and that they exhibit a lower body mass index. When defining the percentage of subjects classified in the “healthy zone”, the BMI numbers in boys from rural areas that are in the healthy zone are higher than those of boys from urban areas. Regarding girls, the ones from urban areas as well as those from rural areas have almost the same percentage in the healthy zone. Concerning fat, it is males in the rural areas that have more pupils in the healthy zone. As for girls, the ones from the urban areas have better results in the three zones, being the healthy zone that has a higher percentage of girls. In the relationship between the genders, boys have better results in the levels of physical aptitude and obesity. In the relationship between the areas, the urban one shows better results. The existence of two periods of analysis allowed us to notice an improvement in all the tests

Relationship between performance, dry-land power and kinematics in master swimmers

The purpose of the study was to analyze the relationships between sprint swimming performance, dry-land power, and kinematics in master swimmers. Twenty-two male master swimmers were separated in two groups based on their chronological age: (i) 30–39 years and; (ii) 40–49 years. Maximum dry-land power was determined through counter movement jump and 3 kg medicine ball throwing (Hmax and Tmax, respectively). Kinematic determinants of performance were measured during a maximal bout of 15, 25 and 50 m front crawl (T15, T25, T50). Stroke frequency (SF), stroke length (SL) and stroke index (SI) were calculated as kinematical aspects of the stroke. In the 30-39 group, SI25 was correlated to T25 (r = –0.76, p < 0.01, η2 = 0.96), the same was observed between SI50 and T50 (r = –0.83, p < 0.01, η2 = 0.96). Only SI50 was significantly correlated to T50 (r = –0.86, p < 0.01, η2 = 0.97) in the 40–49 years age cohort. In dryland power variables, Hmax and Tmax were only correlated in the younger master swimmers group (r = –0.87, p < 0.01, η2 = 0.97). There were no significant differences (p < 0.05) between younger (30–39 years) and older (40–49 years) swimmers groups in dry-land tests (Hmax 28.5 ± 5.9 vs. 26.5 ± 3.9 cm and Tmax 4.2 ± 1.0 vs. 4.2 ± 1.1 m). Our results suggest that swimming performance in younger master swimmers (30–39 years) seem more dependent on kinematic swimming variables than on strength parameters, which were most related to swimming performance in the older master swimmers (40–49 years)

Stationary roller versus velodrome for maximal cycling test: a comparison

The present study aimed to compare the acute cardio-respiratory responses of elite cyclists to a maximal progressive exercise carried out in two different conditions: in a laboratory (using a braked roller) and in an uncovered velodrome. In both testing conditions, ten elite male cyclists (age, 22.3 ± 3.9 years) performed a maximal discontinuous progressive test of 6 minutes per level with 150 W of initial load and increasing 50 W at each level until exhaustion. The heart rate and the ventilation parameters were measured breath-by-breath using a portable metabolic cart gas analysis system with telemetry data transmission. In the first 4 levels of effort, no significant differences were found between the two test conditions regarding VO2, (p=0.193), heart rate (p=0.973) and pedaling cadence (p=0.116). Comparing the maximum values achieved by each athlete in both exercise conditions, significant differences were found for heart rate (p=0.008) and pedaling cadence (p=0.005) but not for VO2max and peak power. Each variable showed a strong correlation between both assessments (VO2, r=0.984, p=0,000; heart rate, r=0.944, p=0.005; pedaling cadence, r=0.900, p=0.014). The amount of variability explained by the linear regression model for both cardio-respiratory parameters also showed a good fit value close to one (VO2max, r2=0.968; heart rate, r2=0.892). Our results suggest that identical cycling protocols conducted in different testing conditions with the same bike leads to equivalent performance but significantly different pedaling cadence and heart rate responses

Occlusion technique in swimming: a training method to improve exchange block time in swimming relays

Swimming relay events have the concern regarding a good start is shared between the incoming and outgoing swimmers. The aim of this study was to evaluate changes in exchange block time (eBT) for swimming relay events as a result of a four-week training program using the occlusion technique. MeThodS: Twenty-eight national swimmers, 12 males (age: 17±1.83 years) and 16 females (age: 19.94±5.65 years) participated in this study. Subjects were required to undergo a training program on visual perception in relay swimming over the course of four weeks; they watched videos corresponding to the last movements of a swimmer during a 4×100m freestyle relay event. The videos were presented with temporal occlusion corresponding to predetermined approaching distances (7.5 m, 5.0 m, and 2.5 m). Swimmers were required to simulate a typical position for exiting the block and to estimate the time-to-contact of the incoming swimmer. The eBT was collected during a real 4×100-m freestyle competition before and after the application of the training program. RESULTS: Female swimmers showed a decreased in EBT, with an improvement of 1.42%, despite there not being a signifcant difference (p=0.68). The male swimmers had a higher improvement in eBT after the training, with a decrease of 13.34% (p=0.68). coNcluSioNS: Visual perception practice using video occlusion techniques seems to have a positive effect. on eBT in swimming relay events, particularly in female swimmersinfo:eu-repo/semantics/publishedVersio

The effects of concurrent resistance and endurance training follow a detraining period in elementary school students

The purpose of this study was to compare the effects of an 8-week training period of resistance training alone (GR), or combined resistance and endurance training (GCOM), followed by 12 weeks of detraining (DT) on body composition, explosive strength, and ·VO₂max adaptations in a large sample of adolescent school boys. Forty-two healthy boys recruited from a Portuguese public high school (age: 13.3 ± 1.04 years) were assigned to 2 experimental groups to train twice a week for 8 weeks: GR (n = 15), GCOM (n = 15), and a control group (GC: n = 12; no training program). Significant training-induced differences were observed in 1- and 3-kg medicine ball throw gains (GR: +10.3 and +9.8%, respectively; GCOM: +14.4 and +7%, respectively), whereas no significant changes were observed after a DT period in both the experimental groups. Significant training-induced gains in the height and length of the countermovement (vertical-and-horizontal) jumps were observed in both the experimental groups. No differences were perceived after a DT period in lower limb power. Time at 20 m decreased significantly for both intervention programs (GR: -11.5% and GCOM: -12.4%, <0.00), but either GR or GCOM groups kept the running speed after a DT period of 12 weeks. After training, the ·VO₂max increased only significantly for GCOM (4.6%, p = 0.01). A significant loss was observed after a DT period in GR but not in GCOM. Performing resistance and endurance training in the same workout does not impair strength development in young school boys. As expected, strength training by itself does not improve aerobic capacity. Our results also suggest that training program effects even persist at the end of the DT period.info:eu-repo/semantics/publishedVersio

The Coaches’ perceptions and experience implementing a long-term athletic development model in competitive swimming

The aim of this study was to analyze the association between coaches’ experience and their perceptions on the implementation of a long-term athletic development (LTAD) model created in 2016 by the Portuguese Swimming Federation. Eighty-six swimming coaches were assembled in groups according to their experience level: “novice” (n = 24), “intermediate” (n = 26), and “experienced” (n = 36), and they answered a questionnaire with the following items: (i) awareness of the existing model (ii) acceptance (iii) usefulness for practice, and (iv) implementation of this model by their peers. Regardless of experience, ~67% of the coaches were aware of the model. Among those, a large number showed acceptance (~95%) and confidence in its usefulness (~83%) for their daily practice. Most coaches (92%) showed concerns about the fact that their peers do not respect the model frameworks, declaring the search for their swimmers’ immediate success (~58%) as the main cause for such behavior. The results also showed an association between experience and knowledge about the model’s existence [χ2 (2) = 10.223, p < 0.01, V = 0.345], and experienced coaches exhibited better knowledge than their intermediate [χ2 (2) = 9.555, p < 0.01, V = 0.393] or novice [χ2 (2) = 5.926, p = 0.02, V = 0.314] counterparts. While there was an association between the coaches’ experience and knowledge about the LTAD model’s existence, this situation does not seem to influence the way coaches accept and understand the usefulness of the model for their daily practice.This project was supported by the National Funds through the Portuguese Foundation for Science and Technology (FCT), I.P (UIDB04045/2020). This work was also supported by the Portuguese Swimming Federation.info:eu-repo/semantics/publishedVersio

THE RELATIONSHIP BETWEEN FRONT CRAWL PERFORMANCE AND HYDRODYNAMICS IN YOUNG FEMALE SWIMMERS

The aim of this study was to analyse the relationship between front crawl performance and hydrodynamic variables during leg kicking. Sixteen female swimmers (9.2±0.6 years) participated in this study. The 200m front crawl performance, the 200m front crawl kicking performance and the active drag during leg kicking were measured. The velocity perturbation method was used to determine active drag. The 200m front crawl performance was significantly correlated with performance in 200m kicking (0.89), with hydrodynamic drag force during leg kicking (-0.70), and power output in kicking (-0.64). Drag coefficient was not related to the performance in 200 m front crawl. These findings underline the importance of leg kicking to performance in front crawl swimming in these ages and suggests the important role of kicking tasks during training in young swimmers

The relative age effect among elite youth competitive swimmers

The aim of this study was to analyse the relative age effect (RAE) in competitive swimming. The best 50 Portuguese swimmers (12- to 18-year-olds) for the main individual swimming pool events of both genders were considered. Analysis was conducted on 7813 swimming event participants, taking account of respective swimmer birth dates and the Fédération Internationale de Natation points gained. Differences in the distribution of birth dates by quarter year were determined using the Chi-square. A one-way analysis of variance ANOVA was used to test for differences measured in points between individuals by quarterly birth year intervals. A two-way analysis of variance ANOVA was also conducted to test the interaction between gender and seasonal birth date with regard to performance. The results show an inequitable distribution (p<0.01) of birth dates by quarter for almost all age groups and both genders. However, the distribution of birth dates by quarter for each considered swim event shows that RAE seems to exist only for 12-year-old females and 12- to 15-year-old males. Analysing mean swimming performance, post-hoc results (p<0.01) show no consistency in RAE. Higher performance occurs among older swimmers only in 100 m butterfly (female 1998, 1st≠2nd quarter, p=0.003). The results also show no interaction between gender and seasonal birth date (p<0.01). Findings of this study show that a higher number of swimmers, particular males, are born in the first two quarters of the year, although there is mostly no effect of seasonal birth date on performance differences within the top 50 swimmers.info:eu-repo/semantics/publishedVersio