An Evaluation of the Reliability of the Pictorial Scale of Perceived Water Competence and Its Relationship With Actual Water Competence

In its recent development, the Pictorial Scale of Perceived Water Competence (PSPWC) showed good face and construct validity. However, additional reliability and validity research is needed, including test-retest reliability and a demonstration of the relationship between PSPWEC test scores and actual water competence. Toward that aim, we administered the PSPWC to 124 children, aged 5-8 years. We repeated this test administration after one week for a subset of 55 children to determine its test-retest reliability, and the remaining 69 children also performed the fully aligned Actual Aquatic Skills Test (AAST) in an indoor swimming pool to provide data for our investigation of the relationship between PSPWC scores and actual water competence. We found good test-retest reliability, both at the global level (ICC = 0.81, n = 55) and at the level of individual skills (Weighted kappa coefficients from 0.58 to 0.90), with no significant differences between these two test scores. We also found a moderate positive relationship between PSPWC and AAST total scores (r = .64, n = 69), with no significant difference between total scores of actual and perceived water competencies. Children overestimated their competence in three specific skills: the back star, swimming on the front, and diving in deep water. While these results underline specific situations in which children's higher self-perceptions of their water competence are a risk factor for their water safety, these data confirm that the PSPWC is reliable for measuring children's perceived competencies in aquatic education and drowning prevention, and there is further support for its validity through a moderate correlation with actual water competencies.

Exploring the relationship between social support, resilience, and subjective well-being in athletes of adapted sport

Introduction

Sports participation of people with disabilities provide an improvement in their skills, especially on access to social support, which could improve resilience and well-being. This study aims to analyze the association between types of social support (parents, coach, friend, and best friend), resilience and positive and negative affect, in 105 Portuguese athletes with disabilities aged between 13 and 61 years (32 ± 12.35 years).

Methods

Participants answered a short sociodemographic questionnaire, the Portuguese version of the Positive and Negative Affect Schedule, and the Brief Resilience Scale, and a scale for assessing social support from parents, coach, friend, and best friend.

Results

Social support provided by the best friend, coach, friends, and parents had a direct effect on resilience and positive and negative affect. Results showed a positive and significant association between resilience and positive affect (r = 0.28; p = 0.004) and a negative association between resilience and negative affect (r = -0.37; p ≤ 0.001). A strong relationship was found between resilience and affect, with no relationship being verified between the sources of social support and resilience or affect, as hypothesized.

Discussion

For this group of athletes with disability, more than the social support they may have or may feel, resilience proved to be very important for the consequence of sports practice in terms of subjective well-being.

Well-Being, Resilience and Social Support of Athletes with Disabilities: A Systematic Review

Sport for people with disabilities appears to play a positive role in the well-being, resilience and social support of athletes with disabilities. Thus, this systematic review aims to evaluate the effect of adapted sport on the well-being, resilience and social support in a population with disabilities. The Pubmed, Web of Science, Scopus and SportDiscus databases were used, with several descriptors and Boolean operators. A total of 287 studies were identified through searching the databases. After the data extraction process, twenty-seven studies were included for analysis. In general, these studies show that adapted sport has a positive impact on the levels of well-being, resilience and social support resources for people with disabilities, contributing to their personal development, quality of life and integration into society. Considering the impact on the variables studied, these results are important to support and encourage the development of adapted sport.

Differences between Young Children's Actual, Self-perceived and Parent-perceived Aquatic Skills

As drowning is a leading cause of unintentional injury/death in children worldwide, perceptions of their actual aquatic skills are of critical importance. Children's self-perceptions may influence the risks they take, and parental perceptions may influence the degree of supervision deemed to be necessary for children in and around water. Accordingly, we examined the differences between young children's actual, self-perceived and parent-perceived aquatic skills. Using a three-way repeated measures ANCOVA, we analyzed data from 134 child-parent dyads (56.0% boys; M age = 7.1, SD = 1.1 years; and 71.6% mothers). We measured self and parental perceptions of the child's aquatic skills with the 'Pictorial Scale of Perceived Water Competence' (PSPWC), and we applied the exact same 17 test items of the PSPWC to assess the child's actual aquatic skill level in the water. Controlling for years of swimming school experience, within-subject differences between the total scores on the 'Actual Aquatic Skills Test' (AAST) and both the child- and parent-completed PSPWC indicated lower than actual estimates of the children's aquatic skill level. The degree of disagreement against the AAST was more pronounced in parents than in 6-7 year-old children but was similar between parents and 8-9 year-old children, with these patterns being evident regardless of the children's sex. Our study contributes to an ongoing validation of the PSPWC and represents a key advance in assessing and comparing children's actual and perceived aquatic skill competence, using perfectly aligned instruments. Future research and practice might explore children's actual aquatic skills in different contexts (e.g., open water), include perspectives of non-parent caregivers and assess perceived and actual water competence across development.

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.

The effect of school intervention programs on the body mass index of adolescents: a systematic review with meta-analysis

Effective obesity interventions in adolescent populations have been identified as an immediate priority action to stem the increasing prevalence of adult obesity. The purpose of this meta-analysis was to make a quantitative analysis of the impact of school-based interventions on body mass index during adolescence. Studies were retrieved from PubMed, Scopus, Science Direct and Web of Science databases. Results were pooled using a random-effects model with 95% confidence interval considered statistically significant. Of the 18 798 possible relevant articles identified, 12 articles were included in this meta-analysis. The global result showed a low magnitude effect, though it was statistically significant (N = 14 428), global e.s. = -0.055, P = 0.004 (95% CI = -0.092, -0.017). Heterogeneity was low among the studies (I2 = 9.017%). The funnel plot showed no evidence of publication bias. The rank-correlation test of Begg (P = 0.45641) and Egger's regression (P = 0.19459) confirmed the absence of bias. This meta-analysis reported a significant effect favoring the interventions; however, future research are needed since the reported the evidence was of low magnitude, with the studies following a substantial range of approaches and mostly had a modest methodological quality.

Association between sedentary behavior and bone mass in adolescents

The effects of sedentary behavior on adolescents' bone health are controversial because, even in normal weight individuals, the excessive time spent in some specific types of these behaviors appears to have no negative effect on bone health.

PURPOSE

To analyze the relationship between sedentary behaviors and bone mass in adolescents.

METHODS

One hundred four adolescent boys and girls, aged 10 to 14 years, were divided into normal weight and overweight according to weight status. Specific sedentary behaviors (time spent on the Internet for school and non-school purposes, using the computer, watching television, and playing videogames) were assessed by questionnaire, and the total sedentary behavior time by accelerometry. Bone parameters were collected using X-ray absorptiometry, using total and lumbar bone mineral density (BMD) and total and lumbar bone mineral content (BMC) values.

RESULTS

In both groups, the time spent on the Internet for non-school purposes was positively correlated to the total and lumbar BMD. Also, while in the overweight group, the time spent using the computer was negatively correlated to lumbar BMD, and the time spent on the Internet for non-school purposes was positively correlated to the total and lumbar BMC, and in the normal weight group, the time spent on the Internet for non-school purposes was positively correlated to lumbar BMC.

CONCLUSIONS

Adolescents who spend more time in sedentary behavior, especially using the Internet for non-school purposes, have higher BMD and BMC, while normal weight adolescents who spend more time on the computer have lower BMD.

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

BACKGROUND

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 significant 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 swimmers.

Concentration of salivary cortisol and testosterone in elite women football players

This study aims to evaluate the relation between salivary concentrations of cortisol (C), testosterone (T), the ratio T:C and the individual performance of top-level female soccer athletes during official matches. Eighteen female athletes from a national soccer team (age 23.06 ± 4.33 years) participated in the study. Four official matches were analysed and the on-field time of each player as well as the index of individual effectiveness were calculated. Players were classified in two clusters according to their individual performance (cluster 1 – poor individual performance; cluster 2 – good individual performance) using K-means and their hormonal variables were compared. The players of cluster 2 generally revealed higher values (p˂.05) in both the positive actions and individual effectiveness, when compared with the players of cluster 1. The players of both clusters presented identical values of C, T and T:C at the four evaluated matches. The athletes of cluster 2 showed a significant increase in C (p˂.05) and a significant decrease in T and T:C before the games lost (M2 and M5). However, there was no linear relation between the variation of both hormones during the matches and the individual performance of players. Performance in competition revealed significant differences between players, though with no apparent relation to the hormonal kinetics of C and T before and after the matches.

The acquisition of aquatic skills in preschool children: deep versus shallow water swimming lessons

One of the key factors in the swimming teaching-learning process seems to be the variation of water’s depth.However, there are almost no studies about this topic and the existing ones usually follow a basic approach and with no control of the educational program used. It was our purpose to determine the effect of deep versus shallow water differences on developing pre-schoolers’ aquatic skills after 6 months of practice. Twenty-one Portuguese school-aged children of both genders (4.70 ± 0.51 yrs.), inexperienced in aquatic programs, participated in this study. The children were divided into two groups performing a similar aquatic program but in a different water depth: shallow water (n=10) and deep water (n=11). Each participant was evaluated twice for their aquatic readiness using an observation check list of 17 aquatic motor skills: during the first session (T0) and after six months of practice (two sessions per week with a total of 48 sessions) (T1). The aquatic proficiency on each skill was compared between the groups and a stepwise discriminant analysis was conducted to predict the conditions with higher or lower aquatic competence. Results suggested that swimming practice contributed positively to improvements on several basic aquatic skills, in both groups. The results showed that shallow water group managed to acquire a higher degree of aquatic competence particularly in five basic aquatic skills (p< .05): breath control combined with face immersion and eye opening; horizontal buoyancy; body position at ventral gliding; body position at dorsal gliding; leg kick with breath control at ventral body position, without any flutter device. The discriminant function revealed a significant association between both groups and four included factors (aquatic skills) (p< .001), accounting for 88% between group variability. The body position at ventral gliding was the main relevant predictor (r=0.535). Shallow water swimming lessons generated greater aquatic competence in preschool children after a period of 6 months of practice.

Concomitant Radiotherapy with Protracted 5-fluorouracil Infusion in Locally Advanced Carcinoma of the Pancreas: A Phase Ii Study

Aims and Background

To evaluate the efficacy of combined radiation therapy and continuous infusion of 5-fluorouracil in patients with locally advanced carcinoma of the pancreas.

Methods

Between January 1992 and June 1999, 31 patients with locally advanced adenocarcinoma of the pancreas were treated in our Institute. In 20 patients, the tumor (65%) was located in the head of the pancreas and in 11 (35%) in the body or tail; 13 cases also showed involved nodes. Radiation therapy consisted in a median dose of 63 Gy in 33-36 fractions applied to the tumor and regional lymph nodes. Chemotherapy with 5-fluorouracil in continuous infusion, 250 mg/m2 daily, was administered in the first and fifth week of the radiation therapy. Thereafter, 22 patients received 3-10 cycles of adjuvant chemotherapy with same doses. Median follow-up of the series was 20 months. The toxicity of the treatment was scored according to WHO criteria. All patients underwent nutritional assessment at the time of radiochemotherapy.

Results

The median overall survival was 15.2 months (range, 4-42). At restaging, 17 cases (55%) showed no change and 14 (45%) a partial remission. At the end of radiochemotherapy in 8 (26%) of the cases there was indication for pancreatectomy, which was executed in 4 patients. At the time of the study, 2 patients (6.4%) were surgically proven disease free. Eleven of the 13 cases (85%) presenting involved nodes showed that the enlarged lymph nodes had disappeared. Nineteen patients (61%) are alive with clinical evidence of disease and 2 cases are alive with liver metastases; 8 patients (26%) died for disease. In 74% of cases there was complete pain control. Tolerance to the regimen was good. Nutritional assistance was evaluated and was found to be correlated to survival.

Conclusions

The results of the series confirm a good tolerance with low acute toxicity. Tumor down-staging and resectability rates were high, together with prolonged survival and a good quality of life.

Influence of regular soccer or swimming practice on gross motor development in childhood

The objective of this study was to analyse the changes on gross motor development after five (T5), ten (T10) and 30 (T30) months of swimming or soccer practice. The study sample consists of 33 preschool-aged boys (4.8±0.5 yrs.): 11 soccer practitioners; 11 swimming practitioners; 11 controls (no previous involvement in sports). The Test of Gross Motor Development–Second Edition was used to assess common gross motor skills (locomotion, object control skills). Both experimental groups improved significantly in their gross motor quotient and the standard scores for locomotion and object control skills between T5 and T10. At T10, all soccer practitioners have already reached the maximum descriptive rating for the gross motor quotient. Between T10 and T30, swimming practitioners were able to improve the standard scores for object control skills. Main results showed a positive impact of swimming and soccer participation in motor proficiency.

Determination of Aerobic Power Through a Specific Test for Taekwondo - A Predictive Equation Model

Our aim was to verify the concurrent validity of a maximal taekwondo specific test (TST) to predict VO2max through an explanatory model. Seventeen elite male taekwondo athletes (age: 17.59 ± 4.34 years; body height: 1.72 ± 6.5 m; body mass: 61.3 ± 8.7 kg) performed two graded maximal exercise tests on different days: a 20 m multistage shuttle run test (SRT) and an incremental TST. We recorded test time, VO2max, ventilation, a heart rate and time to exhaustion. Significant differences were found between observed and estimated VO2max values [F (2, 16) = 5.77, p < 0.01]; post-hoc subgroup analysis revealed the existence of significant differences (p = 0.04) between the estimated VO2max value in the SRT and the observed value recorded in the TST (58.4 ± 6.4 ml/kg/min and 52.6 ± 5.2 ml/kg/min, respectively). Our analysis also revealed a moderate correlation between both testing protocols regarding VO2max (r = 0.70; p = 0.005), test time (r = 0.77; p = 0.02) and ventilation (r = 0.69; p = 0.03). There was no proportional bias in the mean difference (t = -1.04; p = 0.313), and there was a level of agreement between both tests. An equation/model was used to estimate VO2max during the TST based on the mean heart rate, test time, body height and mass, which explained 74.3% of the observed VO2max variability. A moderate correlation was found between the observed and predicted VO2max values in the taekwondo TST (r = 0.74, p = 0.001). Our results suggest that an incremental specific test estimates VO2max of elite taekwondo athletes with acceptable concurrent validity.

Cortisol, testosterone and mood state variation during an official female football competition

BACKGROUND

Endogenous hormones are essential on the control of physiological reactions and adaptations during sport performance. This study aims to compare the mood state and the salivary levels of cortisol and testosterone during an official female association football tournament.

METHODS

Twenty female football players (22.85±4.2 years) from the Portuguese women's national team were included in the study. Mood, salivary cortisol and testosterone levels were examined in five moments over the championship (M1, neutral measures; M2-M5, on every match day). Saliva samples were collected before breakfast and immediately after each match. Mood was measured by the profile of mood states questionnaire (POMS); hormone levels were measure by immunoassay methods.

RESULTS

Iceberg Profiles of POMS were observed during all the moments of evaluation (M2-M5), showing a decrease in vigor and an increase in tension and depression in both team defeats (M2 and M5). There is no relationship between the hormones levels and the outcome of the competition, once cortisol and testosterone decrease from pre-match to post-match in both wins (M2 and M5) and defeats (M3 and M4). For testosterone the observed decrease is significantly different (P<0.05) before and after all matches.

CONCLUSIONS

Our results show a pattern in mood states behavior. Cortisol and testosterone decrease after match and throughout the tournament, independently of the match outcome. The absence of hormone fluctuations related to competition performance points out that top-level professional football players training systematically and regularly seem to be very well adapted to competition stress effect.

Respostas hormonais da testosterona e do cortisol em contexto competitivo: uma revisão sistemática

<p>Nesta revisão foram analisados os estudos que apresentam resultados da resposta das hormonas consideradas de <em>stresse</em>, o cortisol e a testosterona, claramente associadas a um comportamento psicobiológico relacionado com a competição desportiva. Após uma pesquisa efetuada nas bases de dados <em>ScienceDirect e Medline/Pubmed</em>, foram selecionados sobre esta temática os estudos mais recentes realizados (&gt;2002). A maioria dos estudos recorre a amostras reduzidas e maioritariamente sobre o sexo masculino. O efeito antecipatório à competição, caracterizado por um aumento da ansiedade, geralmente determina um aumento da concentração de ambas as hormonas, em especial um aumento da concentração de cortisol. Estas alterações na resposta hormonal surgem igualmente associadas ao resultado da competição, com concentrações de testosterona mais elevada nos vitoriosos do que nos perdedores, juntamente com estados psicológicos positivos associados à vitória e negativos associados à derrota. O sexo e o nível desportivo do atleta são igualmente considerados fatores diferenciadores do comportamento hormonal em contexto competitivo. Estudos futuros deverão esclarecer os efeitos a longo prazo nessa resposta hormonal em atletas de elite, considerando o treino intenso prévio e a participação regular em competições de elevado nível. Fica também por aprofundar o efeito que determinada resposta hormonal terá no desempenho desportivo sobretudo quando considerada ao longo de um determinado evento competitivo ou torneio.</p>

Reconstruction of bremsstrahlung spectra from attenuation data using generalized simulated annealing

A generalized simulated annealing algorithm, combined with a suitable smoothing regularization function is used to solve the inverse problem of X-ray spectrum reconstruction from attenuation data. The approach is to set the initial acceptance and visitation temperatures and to standardize the terms of objective function to automate the algorithm to accommodate different spectra ranges. Experiments with both numerical and measured attenuation data are presented. Results show that the algorithm reconstructs spectra shapes accurately. It should be noted that in this algorithm, the regularization function was formulated to guarantee a smooth spectrum, thus, the presented technique does not apply to X-ray spectrum where characteristic radiation are present.

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).

In vitro and in vivo evaluation of silicated hydroxyapatite and impact of insulin adsorption

This study evaluates the biological behaviour, in vitro and in vivo, of silicated hydroxyapatite with and without insulin adsorbed on the material surface. Insulin was successfully adsorbed on hydroxyapatite and silicated hydroxyapatite bioceramics. The modification of the protein secondary structure after the adsorption was investigated by means of infrared and circular dichroism spectroscopic methods. Both results were in agreement and indicated that the adsorption process was likely to change the secondary structure of the insulin from a majority of α-helix to a β-sheet form. The biocompatibility of both materials, with and without adsorbed insulin on their surface, was demonstrated in vitro by indirect and direct assays. A good viability of the cells was found and no proliferation effect was observed regardless of the material composition and of the presence or absence of insulin. Dense granules of each material were implanted subcutaneously in mice for 1, 3 and 9 weeks. At 9 weeks of implantation, a higher inflammatory response was observed for silicated hydroxyapatite than for pure hydroxyapatite but no significant effect of adsorbed insulin was detected. Though the presence of silicon in hydroxyapatite did not improve the biological behaviour, the silicon substituted hydroxyapatite remained highly viable.

Abandonment and accessibility in railway historical buildings: Central do Brasil and Leopoldina Railstation

This paper aims to demonstrate the evolution of a study in the city of Juiz de Fora-MG, whose objective is the assessment of areas of train station in relation to the inclusion of people with disabilities and consequently promote the historical and cultural heritage of this city. The railway buildings are important landmarks in the history of the city and its surroundings was formed the first core of urban development. Because this building was of the early nineteenth century, these were not designed to assist people with disabilities, in effect, we observed that the buildings are being underutilized. The difficulty of insertion of incentive policies is therefore not due to the commitment by the majority, making the deployment of new access.

Observation of 2p3d(1Po)→1s3d(1De) radiative transition in He-like Si, S, and Cl ions

We present an experimental determination of the 2p3d(1Po)→1s3d(1De) x-ray line emitted from He-like Si, S, and Cl projectile ions, excited in collisions with thin carbon foils, using a high-resolution bent-crystal spectrometer. A good agreement between the observation and state-of-the-art relativistic calculations using the multiconfiguration Dirac-Fock formalism including the Breit interaction and QED effects implies the dominance of fluorescent decay over the autoionization process for the 2p3d(^{1}P^{o}) state of He-like heavy ions. This is the first observation of the fluorescence-active doubly excited states in He-like Si, S, and Cl ions.

The influence of ACE ID and ACTN3 R577X polymorphisms on lower-extremity function in older women in response to high-speed power training

Background

We studied the influence of the ACE I/D and ACTN3 R577X polymorphisms (single or combined) on lower-extremity function in older women in response to high-speed power training.

Methods

One hundred and thirty-nine healthy older Caucasian women participated in this study (age: 65.5 ± 8.2 years, body mass: 67.0 ± 10.0 kg and height: 1.57 ± 0.06 m). Walking speed (S10) performance and functional capacity assessed by the “get-up and go” (GUG) mobility test were measured at baseline (T1) and after a consecutive 12-week period of high-speed power training (40-75% of one repetition maximum in arm and leg extensor exercises; 3 sets 4–12 reps, and two power exercises for upper and lower extremity). Genomic DNA was extracted from blood samples, and genotyping analyses were performed by PCR methods. Genotype distributions between groups were compared by Chi-Square test and the gains in physical performance were analyzed by two-way, repeated-measures ANOVA.

Results

There were no significant differences between genotype groups in men or women for adjusted baseline phenotypes (P > 0.05). ACE I/D and ACTN3 polymorphisms showed a significant interaction genotype-training only in S10 (P = 0.012 and P = 0.044, respectively) and not in the GUG test (P = 0.311 and P = 0.477, respectively). Analyses of the combined effects between genotypes showed no other significant differences in all phenotypes (P < 0.05) at baseline. However, in response to high-speed power training, a significant interaction on walking speed (P = 0.048) was observed between the “power” (ACTN3 RR + RX & ACE DD) versus “non-power” muscularity-oriented genotypes (ACTN3 XX & ACE II + ID)].

Conclusions

Thus, ACE I/D and ACTN3 R577X polymorphisms are likely candidates in the modulation of exercise-related gait speed phenotype in older women but not a significant influence in mobility traits.

ACE I/D and ACTN3 R/X polymorphisms as potential factors in modulating exercise-related phenotypes in older women in response to a muscle power training stimuli

Genetic variation of the human ACE I/D and ACTN3 R577X polymorphisms subsequent to 12 weeks of high-speed power training on maximal strength (1RM) of the arm and leg muscles, muscle power performance (counter-movement jump), and functional capacity (sit-to-stand test) was examined in older Caucasian women [n = 139; mean age 65.5 (8.2) years; 67.0 (10.0) kg and 1.57 (0.06) m]. Chelex 100 was used for DNA extraction, and genotype was determined by PCR-RFLP methods. Muscular strength, power, and functional testing were conducted at baseline (T1) and after 12 weeks (T2) of high-speed power training. At baseline, the ACE I/D and ACTN3 R/X polymorphisms were not associated with muscle function or muscularity phenotypes in older Caucasian women. After the 12-week high-speed training program, subjects significantly increased their muscular and functional capacity performance (p < 0.05). For both polymorphisms, significant genotype-training interaction (p < 0.05) was found in all muscular performance indices, except for 1RM leg extension in the ACE I/D (p = 0.187). Analyses of the combined effects between genotypes showed significant differences in all parameters (p < 0.05) in response to high-speed power training between the power (ACTN3 RR + RX & ACE DD) versus "non-power" muscularity-oriented genotypes (ACTN3 XX & ACE II + ID)]. Our data suggest that the ACE and ACTN3 genotypes (single or combined) exert a significant influence in the muscle phenotypes of older Caucasian women in response to high-speed power training. Thus, the ACE I/D and ACTN3 R/X polymorphisms are likely factors in modulating exercise-related phenotypes in older women, particularly in response to a resistance training stimuli.

Characterization of heavy-metal contamination in surface sediments of the Minho river estuary by way of factor analysis

Surface sediments were collected in August 2009 from 49 sites along the Minho estuary (between Tui and Caminha) and analyzed for grain size, organic carbon (Corg) and total nitrogen (Ntot) contents, and major (silicon [Si], aluminum [Al], iron [Fe], calcium [Ca], magnesium [Mg], sodium [Na], potassium [K], titanium [Ti], and mangesese [Mn]) and trace element (arsenic [As], chromium [Cr], copper [Cu], mercury [Hg], lithium [Li], lead [Pb], rubidium [Rb], tin [Sn], and zinc [Zn]) concentrations. Factor analysis was used to decrease 22 selected variables into 4 factors accounting for 85.9 % of the total variance explained, suggesting distinct elemental sources or sediment components affecting their spatial distributions. Although factors 1 (detrital component; elements strongly associated with fine- [Na, Mg, Ti, Li, Cr, Cu, Fe, Al, Zn, Ca, and As] and coarse-grained sediments [Si, K, Rb; mean grain-size [MGS]) and 3 (Fe-Mn oxyhydroxide sediment component; Fe, Mn, As, fine fraction) are interpreted as reflecting predominance of natural contributions, factors 2 (urban and industrial contamination: sediment components [Pb, Hg, organic carbon [Corg], total nitrogen [Ntot] and 4 (components associated with contamination by nautical activities; the association of tin [Sn] and calcium [Ca]) seem to indicate anthropogenic contributions). Nevertheless, the influence of elemental contributions derived from tungsten (W)-Sn mineralizations and those resulting from mining activities can also contribute to the obtained geochemical associations and should be considered. Spatial distribution of dominant factor scores shows the dominance of factors 2 and 4 between Tui and Vila Nova de Cerveira, whereas samples dominated by factors 3 and 1 are found between Ilha da Boega and Seixas and in the Caminha areas, respectively. Despite the dominance of factor score 1 in the Caminha area, the distribution pattern of dominant factor scores shows samples dominated by other factor scores that can be explained by dredging activities in this river sector that restore ancient sedimentary characteristics or expose contaminated sediments. Through the identification of sample locations dominated by factors associated with contamination, it will be possible to select them as priority areas where new environmental (e.g., toxicity tests, organic Sn compounds, tracers of sewage contamination) studies should be implemented in the future.

Effects of Two Different Training Programs with Same Workload on Throwing Velocity by Experienced Water Polo Players

To investigate the effects of two different strength-training programs with the same workload (impulse) on throwing velocity in water polo, 30 water polo players ( M age = 17.1 yr., SD = 4.9; M mass = 71.2 kg, SD = 14.7; M height =1.75 m, SD = 0.09 m) were randomly divided in two groups based upon throwing performance with water polo ball. The medicine-ball training group performed 3 × 6 reps with a 3-kg medicine ball, while the combination training group completed 1 × 9 repetitions with the 3-kg medicine ball, followed by 3 × 14 repetitions with a water polo ball. Both groups trained eight weeks twice per week in addition to their regular water polo training. Throwing velocity was measured with a Doppler radar gun before and after the training period. Testing included throws with a water polo ball on land and in water, as well as with 1-kg and 3-kg medicine balls on land. Statistically significant increases were found in mean peak throwing velocity with the water polo, 1-kg, and 3-kg medicine balls after training. No differences between the groups were found, except in throwing velocity with water polo on land, with a statistically significantly larger increase for the combination training group (+ 7.6%) than the medicine-ball training group (+ 3.4%). These findings indicate that after training with the same workload (impulse), increases in throwing velocity in water polo are similar and suggesting workload may be a critical variable for training results.

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.

Genetic inheritance effects on endurance and muscle strength: an update

Top-level sport seems to play a natural Darwinian stage. The most outstanding athletes appear to emerge as a result of exogenous influences of nature and/or coincidence, namely, the contingency of practicing certain sport for which their talents best fit. This coincidence arises because certain individuals possess anatomical, metabolic, functional and behavioural characteristics that are precisely those required to excel in a given sport. Apart from the effects of training, there is strong evidence of genetic influence upon athletic performance. This article reviews the current state of knowledge regarding heritable genetic effects upon endurance and muscle strength, as reported by several twin and family studies. Due, probably, to the inaccuracy of the measurement procedures and sampling error, heritability estimates differ widely between studies. Even so, the genetic inheritence effects seem incontrovertible in most physical traits: ~40-70% for peak oxygen uptake and cardiac mass and structure, and ~30-90% for anaerobic power and capacity, ranging according to the metabolic category. Studies in development by several researchers at this present time seem to guarantee that future reviews will include twins and family studies concerning genes associated with the adaptive processes against hormetic agents, such as exercise, heat and oxidative stress.

High Level Swimming Performance and its Relation to Non-Specific Parameters: A Cross-Sectional Study on Maximum Handgrip Isometric Strength

The relationship between handgrip isometric strength and swimming performance was assessed in the four competitive swimming strokes in swimmers of different age groups and of both sexes. 78 national-level Portuguese swimmers (39 males, 39 females) were selected for this study. Grip strength, previously used as a marker of overall strength to predict future swimming performance, was measured using a hand dynamometer. The best competitive time at 100 and 200 m in all four swimming strokes were converted into 2010 FINA points. Non-parametric tests were used to evaluate differences between groups. Pearson product-moment correlations were computed to verify the association between variables. Handgrip maximum isometric strength was significantly correlated with swimming performance, particularly among female swimmers. Among female age group swimmers, the relationship between handgrip and 100-m freestyle was significant. Handgrip isometric strength seems to be related to swimming performance, especially to 100-m freestyle and in female swimmers. For all other distances and strokes, technique and training probably are more influential than semi-hereditary strength markers such as grip strength.

Effects of high-speed power training on functional capacity and muscle performance in older women

The purpose of the study was to examine the effects of 12 weeks high-speed power training on isometric contraction (handgrip strength), maximal strength (1RM), muscle power (walking velocity, counter movement jump and ball throwing) and functional tasks of the arm and leg muscles (sit-to-stand and get-up and go). Fifty-six older women were divided into an experimental group and a control group [EG, n=28, 62.5 (5.4) years; CG: n=28, 62.5 (4.3) years]. The EG was submitted to a high-speed power training that consisted of 40% of one repetition maximum (1<RM) to 75% of 1RM); 3 sets 4-12 reps, countermovement jump and medicine ball (1.5 kg) throwing. Over the 12-week training period, the EG significantly increased dynamic and isometric strength performance (57% to 61%), muscle power (range from 14% to 40%) (P<0.05) and function (P<0.05). No significant magnitudes of increase were observed in the CG. These data indicate that high-speed power training is an effective exercise approach leading to large gains in upper and lower extremity muscle performance and function capacity.

Strength training and detraining in different populations: case studies

Many researchers have demonstrated that a specific strength training program can improve maximal strength and, the rate of force production, reduce the incidence of muscle-skeletal injury, and contribute to faster injury recovery times, thereby minimizing the number of missed practice sessions or competitions. Yet, to our best knowledge, there is no apparent consensus on the appropriate method of muscle strength and power training to enhance performance in distinct populations groups. Interruptions in training process because of illness, injury, holidays, post-season break or other factors are normal situations in any kind of sport. However, the detraining period and its consequences are not well reported in sports literature, and namely during puberty. Therefore, the aim of this paper was to discuss several case studies concerning different populations such us physical students, age-swimming competitors and elite power athletes.

The effects of concurrent resistance and endurance training follow a specific detraining cycle in young school girls

The purpose of this study was to compare the effects of an 8-week training period of strength training alone (GR), or combined strength and endurance training (GCOM), followed by 12-weeks of de-training (DT) on body composition, power strength and VO2max adaptations in a schooled group of adolescent girls.

METHODS

Sixty-seven healthy girls recruited from a Portuguese public high school (age: 13.5+1.03 years, from 7(th) and 9th grade) were divided into three experimental groups to train twice a week for 8 wks: GR (n=21), GCOM (n=25) and a control group (GC: n=21; no training program). Anthropometric parameters variables as well as performance variables (strength and aerobic fitness) were assessed.

RESULTS

No significant training-induced differences were observed in 1kg and 3kg medicine ball throw gains (2.7 to 10.8%) between GR and GCOM groups, whereas no significant changes were observed after a DT period in any of the experimental groups. Significant training-induced gains in CMVJ (8 to 12%) and CMSLJ (0.8 to 5.4%) were observed in the experimental groups. Time of 20m significantly decreased (GR: -11.5% and GCOM: -10%) after both treatment periods, whereas only the GR group kept the running speed after a DT period of 12 weeks. After training VO2max increased only slightly for GCOM (4.0%). No significant changes were observed after the DT period in all groups, except to GCOM in CMVJ and CMSLJ.

CONCLUSION

Performing simultaneous strength and endurance training in the same workout does not appear to negatively influence power strength and aerobic fitness development in adolescent girls. Indeed, concurrent strength and endurance training seems to be an effective, well-rounded exercise program that can be prescribed as a means to improve initial or general strength in healthy school girls. De-training period was not sufficient to reduce the overall training effects.

Does combined dry land strength and aerobic training inhibit performance of young competitive swimmers?

THE AIM OF THE CURRENT STUDY WAS TWOFOLD

(i) to examine the effects of eight weeks of combined dry land strength and aerobic swimming training for increasing upper and lower body strength, power and swimming performance in young competitive swimmers and, (ii) to assess the effects of a detraining period (strength training cessation) on strength and swimming performance. The participants were divided into two groups: an experimental group (eight boys and four girls) and a control group (six boys and five girls). Apart from normal practice sessions (six training units per week of 1 h and 30 min per day), the experimental group underwent eight weeks (two sessions per week) of strength training. The principal strength exercises were the bench press, the leg extension, and two power exercises such as countermovement jump and medicine ball throwing. Immediately following this strength training program, all the swimmers undertook a 6 week detraining period, maintaining the normal swimming program, without any strength training. Swimming (25 m and 50 m performances, and hydrodynamic drag values), and strength (bench press and leg extension) and power (throwing medicine ball and countermovement jump) performances were tested in three moments: (i) before the experimental period, (ii) after eight weeks of combined strength and swimming training, and (iii) after the six weeks of detraining period. Both experimental and control groups were evaluated. A combined strength and aerobic swimming training allow dry land strength developments in young swimmers. The main data can not clearly state that strength training allowed an enhancement in swimming performance, although a tendency to improve sprint performance due to strength training was noticed. The detraining period showed that, although strength parameters remained stable, swimming performance still improved. Key pointsThis study investigated the effect of dry land strength training on sprint performance in young competitive swimmers.A combined strength and aerobic swimming training allow dry land strength developments in young swimmers.The main data can not clearly state that strength training allowed an enhancement in swimming performance, although a tendency to improve sprint performance due to strength training was noticed.The detraining period showed that, although strength parameters remained stable, swimming performance still improved.