Examining the accumulated oxygen deficit method in breaststroke swimming

The present study investigated the accumulated oxygen deficit (AOD) method in breaststroke swimming with the aims to assess the reliability of the oxygen uptake/swimming velocity regression line and to quantify the precision of the AOD. Sixteen male swimmers performed two swimming tests in different days, with a 24-h recovery between tests: a graded swimming test and an all-out test. The all-out test was performed in one of two distances: 100 m (n = 7) or 200 m (n = 9). Through all testing, expired gases were collected breath by breath and analysed with a K4b2 Gas Analyser (Cosmed, Rome, Italy) connected to an AquaTrainer Valve (Cosmed, Rome, Italy). The standard error of the regression lines was approximately 5-6 ml kg(-1) min(-1) and the regressions allowed an extrapolation of the energy cost to higher intensities with a standard error of the predicted value that was lower in the 200-m bout (approximately 3.5 ml kg(-1) min(-1)) comparatively to the 100-m bout (approximately 6 ml kg(-1) min(-1)). The AOD imprecision was calculated as the square root of the sum of the oxygen uptake measurement error and the standard error of the predicted value for energy cost. AOD imprecision was smaller in the 200-m bout (approximately 9 ml kg(-1) min(-1)) comparatively to the 100-m bout (approximately 12 ml kg(-1) min(-1)). However, since the AOD values during the two distances were small, the AOD relative errors can be viewed as high. Additionally, the data variability was considerable (95% confidence intervals of the linear extrapolation larger than 20 ml kg(-1) min(-1)).info:eu-repo/semantics/publishedVersio

Can 8-weeks of Training Affect Active Drag in Young Swimmers?

The aim of this study was to assess the effects of 8-weeks of training on active drag in young swimmers of both genders. Eight girls and twelve boys' belonging to the same swimming team and with regular competitive participation in national and regional events for the previous two seasons participated in this study. Active drag measurements were conducted in two different evaluation moments: at the beginning of the season and after 8 weeks of training (6.0 ± 0.15 training units per week, 21.00 ± 3.23 km per week and 3.50 ± 0.23 km per training unit). The maximal swimming velocity at the distance of 13 m, active drag and drag coefficient were measured on both trials by the method of small perturbations with the help of an additional hydrodynamic body. After 8 weeks of training, mean active drag (drag force and drag coefficient) decreased in girls and boys, although no significant differences were found between the two trials. It seems that 8 weeks of swimming training were not sufficient to allow significant improvements on swimming technique. Key pointsThe velocity perturbation method seems to be a good, simple and reliable approach to assess active drag in young swimmers.Eight weeks of swimming training were not sufficient to allow significant improvements on swimming hydrodynamics.There were no differences between boys and girls concerning active drag. A possible explanation may be related to the similar values of body mass and height in boys and girls found in this study.Specific training sets concerning technique correction and improvement in young swimmers might be a main aim during training planning.info:eu-repo/semantics/publishedVersio

Dynamic mechanical behavior of starch-based scaffolds in dry and physiologically simulated conditions: effect of porosity and pore size

The three-dimensional scaffolds of a blend of starch and poly(L-lactic) acid, SPLA70, were produced using compression molding of polymer/salt mixture followed by leaching of salt. One series of scaffolds were prepared with varying polymer-to-salt ratio while keeping the salt size constant, and the other series of scaffolds were prepared with varying salt sizes while keeping the polymer-to-salt ratio constant. The X-ray microcomputed tomography and scanning electron microscopy assay were used to analyze the porous morphologies, porosity and distribution of porosity of the porous scaffolds. Salt-free and integrated SPLA70 scaffolds with porosities ranging from 74% to 82% and pore sizes of 125–250 to 500–1000 lm can be fabricated using the present fabrication technique. The water uptake of the SPLA70 scaffolds increases with increasing porosities and also with increasing pore size. In dry state, the storage modulus decreases with increasing porosity and also with increasing pore size. The normalized modulus values are related to normalized density of the scaffolds by a power-law function with an exponent between 2 and 3. For the immersed scaffolds under physiological conditions, the storage modulus was less dependent on porosity and pore size. However, the loss factor increased significantly compared with dry state measurements. The present study clearly shows that the mechanical performance of porous polymeric constructs in dry and in immersed state is completely different, and for comparison with biomechanical performance of tissues, the tests should ideally be performed in immersed state

Using community phylogenetics to assess phylogenetic structure in the fitzcarrald region of Western Amazonia

© 2020 The Authors. Di versity and Distributions Published by SBI. Here we explore the use of community phylogenetics as a tool to document patterns of biodiversity in the Fitzcarrald region, a remote area in Southwestern Amazonia. For these analyses, we subdivide the region into basin-wide assemblages encompassing the headwaters of four Amazonian tributaries (Urubamba, Yuruá, Purús and Las Piedras basins), and habitat types: river channels, terra firme (non-floodplain) streams, and floodplain lakes. We present a robust, well-documented collection of fishes from the region including 272 species collected from 132 field sites over 63 field days and four years, comprising the most extensive collection of fishes from this region to date. We conduct a preliminary community phylogenetic analysis based on this collection and recover results largely statistically indistinguishable from the random expectation, with only a few instances of phylogenetic structure. Based on these results, and of those published in other recent biogeographic studies, we conclude that the Fitzcarrald fish species pool accumulated over a period of several million years, plausibly as a result of dispersal from the larger species pool of Greater Amazonia

Inconsistency in shoulder arthrometers for measuring glenohumeral joint laxity: a systematic review

There is no consensus on how to measure shoulder joint laxity and results reported in the literature are not well systematized for the available shoulder arthrometer devices. This systematic review aims to summarize the results of currently available shoulder arthrometers for measuring glenohumeral laxity in individuals with healthy or injured shoulders. Searches were conducted on the PubMed, EMBASE, and Web of Science databases to identify studies that measure glenohumeral laxity with arthrometer-assisted assessment. The mean and standard deviations of the laxity measurement from each study were compared based on the type of population and arthrometer used. Data were organized according to the testing characteristics. A total of 23 studies were included and comprised 1162 shoulders. Populations were divided into 401 healthy individuals, 278 athletes with asymptomatic shoulder, and 134 individuals with symptomatic shoulder. Sensors were the most used method for measuring glenohumeral laxity and stiffness. Most arthrometers applied an external force to the humeral head or superior humerus by a manual-assisted mechanism. Glenohumeral laxity and stiffness were mostly assessed in the sagittal plane. There is substantial heterogeneity in glenohumeral laxity values that is mostly related to the arthrometer used and the testing conditions. This variability can lead to inconsistent results and influence the diagnosis and treatment decision-making.This article is a result of the project DILATO (reference 47289) supported by the Norte Portugal Regional Operational Programme (NORTE 2020), under the PORTUGAL 2020 Partnership Agreement, through the European Regional Development Fund (ERDF)

The influence of the level of physical activity and human development in the quality of life in survivors of stroke

<p>Abstract</p> <p>Background</p> <p>The association between physical activity and quality of life in stroke survivors has not been analyzed within a framework related to the human development index. This study aimed to identify differences in physical activity level and in the quality of life of stroke survivors in two cities differing in economic aspects of the human development index.</p> <p>Methods</p> <p>Two groups of subjects who had suffered a stroke at least a year prior to testing and showed hemiplegia or hemiparesis were studied: a group from Belo Horizonte (BH) with 48 people (51.5 ± 8.7 years) and one from Montes Claros (MC) with 29 subjects (55.4 ± 8.1 years). Subsequently, regardless of location, the groups were divided into Active and Insufficiently Active so their difference in terms of quality of life could be analyzed.</p> <p>Results</p> <p>There were no significant differences between BH and MCG when it came to four dimensions of physical health that were evaluated (physical functioning, physical aspect, pain and health status) or in the following four dimensions of mental health status (vitality, social aspect, emotional aspect and mental health). However, significantly higher mean values were found in Active when compared with Insufficiently Active individuals in various measures of physical health (physical functioning 56.2 ± 4.4 vs. 47.4 ± 6.9; physical aspect 66.5 ± 6.5 vs. 59.1 ± 6.7; pain 55.9 ± 6.2 vs. 47.7 ± 6.0; health status 67.2 ± 4.2 vs. 56.6 ± 7.8) (arbitrary units), and mental health (vitality 60.9 ± 6.8 vs. 54.1 ± 7.2; social aspect 60.4 ± 7.1 vs. 54.2 ± 7.4; emotional aspect 64.0 ± 5.5 vs. 58.1 ± 6.9; mental health status 66.2 ± 5.5 vs. 58.4 ± 7.5) (arbitrary units).</p> <p>Conclusions</p> <p>Despite the difference between the cities concerning HDI values, no significant differences in quality of life were found between BH and MCG. However, the Active group showed significantly better results, confirming the importance of active lifestyle to enhance quality of life in stroke survivors.</p

Effects of Ibuprofen intake in muscle damage, body temperature and muscle power in Paralympic powerlifting athletes

The aim of this study is to evaluate the effect of ingesting ibuprofen on post-workout recovery of muscle damage, body temperature and muscle power indicators in Paralympic powerlifting athletes. The study was carried out with eight Paralympic powerlifting athletes (aged 27.0 ± 5.3 years and 79.9 ± 25.5 kg of body mass) competing at the national level, with a minimum training experience of 12 months, who all submitted to two experimental conditions: Ibuprofen (2 × 00 mg) and control. The maximal isometric force of the upper limbs and rate of force development, thermography, and serum biochemical analyzes of creatine kinase, lactate dehydrogenase, aspartate aminotransferase and alanine aminotransferase were measured before, after, 24 h after and 48 h after the intervention. Maximal isometric force only decreased in the placebo condition, which increased back to baseline levels, while no substantial decline in baseline force was seen in the ibuprofen condition, although no effect for exercise condition was detected. After the exercise, the rate of force development decreased significantly for both conditions and did not exceed baseline levels again after 48 h. Muscle temperature decreased significantly at 48-h post-exercise in the placebo condition, when compared with the previous day of measurement; and deltoid muscle temperature at 48-h post-exercise was higher with the ibuprofen condition. Although the results indicate some positive effects of ibuprofen use, they do not enable a clear statement regarding its positive effects on muscle function and muscle damage. Ibuprofen seems to have caused a delay in the anti-inflammatory response following exercise.publishedVersio