Bronchobiliary fistula after stenting of biliary duct as the management of iatrogenic bile duct injury during elective cholecystectomy.

BACKGROUND: Bronchobiliary fistula is a rare and complex entity defined by an abnormal communication between the biliary and bronchial systems. The etiopathogenesis is not completely understood, but the most common factors implicated are hepatobiliary tumors, biliary obstruction, iatrogenic damage or trauma. METHODS: Here we present a case of a 69-year-old man that developed a bronchobiliary fistula and a pulmonary abscess after migration of a bile duct stent placed as part of the treatment of an iatrogenic bile duct injury that occurred during elective cholecystectomy. RESULTS: A conservative approach, that included broad-spectrum antibiotic, removal of the stent, and sphincterotomy, was enough for the closure of the fistula and resolution of the symptoms. CONCLUSION: We emphasize the importance of prompt recognition of this entity and a concerted therapeutic strategy to optimize the probability of success, avoiding the destructive consequences of the bile in the pulmonary parenchyma and septic complications.

Impact on sexual function of surgical treatment in rectal cancer.

INTRODUCTION: The development of new surgical techniques and medical devices, like therapeutical multimodal approaches has allowed for better outcomes on patients with rectal cancer (RCa). Owing to that, an increased awareness and investment towards better outcomes regarding patients' sexual and urinary function has been recently observed. AIM: Evaluate and characterize the sexual dysfunction of patients submitted to surgical treatment for RCa. MATERIALS AND METHODS: An observational retrospective study including all male patients who underwent a surgical treatment for RCa between January 2011 December 2014 (n=43) was performed, complemented with an inquiry questionnaire to every patient about its sexual habits and level of function before and after surgery. DISCUSSION: All patients were male, with an average of 64yo. (range 42-83yo.). The surgical procedure was a rectum anterior resection (RAR) in 22 patients (56%) and an abdominoperineal resection (APR) in 19(44%). Sixty three percent described their sexual life as important/very important. Sexual function worsening was observed in 76% (65% with complains on erectile function, and 27% on ejaculation). Fourteen patients (38%) didn't resume sexual activity after surgery. Increased age (p=0.007), surgery performed (APR) (p=0.03) and the presence of a stoma (p=0.03) were predictors of ED after surgery. A secondary analysis found that the type of surgery (APR) (p=0.04), lower third tumor's location (p=0.03) and presence of comorbidities (p=0.013) (namely, smokers and diabetic patients) were predictors of de novo ED after surgery. CONCLUSIONS: This study demonstrated the clear negative impact in sexual function of patients submitted to a surgical treatment for RCa. Since it is a valued feature for patients, it becomes essential to correctly evaluate/identify these cases in order to offer an adequate therapeutical option.

Neuromuscular fatigue during 200 m breaststroke.

THE AIMS OF THIS STUDY WERE: i) to analyze activation patterns of four upper limb muscles (duration of the active and non-active phase) in each lap of 200m breaststroke, ii) quantify neuromuscular fatigue, with kinematics and physiologic assessment. Surface electromyogram was collected for the biceps brachii, deltoid anterior, pectoralis major and triceps brachii of nine male swimmers performing a maximal 200m breaststroke trial. Swimming speed, SL, SR, SI decreased from the 1(st) to the 3(rd) lap. SR increased on the 4(th) lap (35.91 ± 2.99 stroke·min(-1)). Peak blood lactate was 13.02 ± 1.72 mmol·l(-1) three minutes after the maximal trial. The EMG average rectified value (ARV) increased at the end of the race for all selected muscles, but the deltoid anterior and pectoralis major in the 1(st) lap and for biceps brachii, deltoid anterior and triceps brachii in the 4(th) lap. The mean frequency of the power spectral density (MNF) decreased at the 4(th) lap for all muscles. These findings suggest the occurrence of fatigue at the beginning of the 2(nd) lap in the 200m breaststroke trial, characterized by changes in kinematic parameters and selective changes in upper limb muscle action. There was a trend towards a non-linear fatigue state. Key PointsFatigue in the upper limbs occurs in different way as it described by 100m swimming events.Neuromuscular fatigue was estimated by analyzing the physiological changes (high blood lactate concentrations), biomechanical changes in the swimming stroke characteristics (decreased in swimming velocity), and by the changes in the EMG amplitude and frequency parameters at the end of the swimming bout.The amplitude signal of EMG provided by the ARV demonstrated an increase at the end with the respect to the beginning for all muscles under study, excepted for the muscle deltoid anterior.The mean frequency (MNF) in our study decrease at the end of the swimming in the 4(th) lap relative to the 1(st) lap for all muscles under observation, along the 200m breaststroke.

Detraining and Retraining Effects from a Multicomponent Training Program on the Functional Capacity and Health Profile of Physically Active Prehypertensive Older Women.

BACKGROUND: Resuming a physical exercise program after a period of cessation is common in older women. Monitoring the responses during this detraining (DT) and retraining (RT) may allow us to analyze how the body reacts to an increase and a reduction in physical inactivity. Therefore, we conducted a follow-up training, DT, and RT in prehypertensive older women to analyze the response to these periods. METHODS: Twenty-three prehypertensive older women (EG; 68.3 ± 2.8 years; 1.61 ± 0.44 m) performed 36 weeks of the multicomponent training program (MTP) followed by twelve weeks of DT plus eight weeks of RT. Fifteen prehypertensive older women (CG; 66.3 ± 3.2 years; 1.59 ± 0.37 m) maintained their normal routine. Functional capacity (FC), lipid, and hemodynamic profile were assessed before, during 24 and 36 weeks of the MTP, after 4 and 12 weeks of DT, and after 8 weeks of RT. RESULTS: After 24 weeks of the MTP, only SBP did not improve. Four weeks of DT did not affect lower body strength (30-CS), TC, or GL. Eight weeks of RT improved BP (SBP: -2.52%; ES: 0.36; p < 0.00; DBP: -1.45%; ES: 0.44; p < 0.02), handgrip strength (3.77%; ES: 0.51; p < 0.00), and 30-CS (3.17%; ES: 0.38; p < 0.04) compared with 36 weeks of the MTP. CONCLUSIONS: Eight weeks of RT allowed patients to recover the benefits lost with detraining, which after only four weeks affected them negatively, and the systematic practice of exercise contributed to greater regulation of BP since 24 weeks of the MTP proved not to be enough to promote positive effects of SBP.

Tracking the performance, energetics and biomechanics of international versus national level swimmers during a competitive season.

The purpose of this study was to track and compare the changes of performance, energetic and biomechanical profiles of international (Int) and national (Nat) level swimmers during a season. Ten Portuguese male swimmers (four Int and six Nat level subjects) were evaluated on three different time periods (TP(1), TP(2), TP(3)) of the 2009-2010 season. Swimming performance was assessed based on official time's lists of the 200-m freestyle event. An incremental set of 7 × 200 m swims was applied to assess the energetic and biomechanical data. Measurements were made of: (1) velocity at the 4 mmol of lactate levels (V4), stroke index at V4 (SI@V4) and propelling efficiency at V4 (η (p)@V4), as energetic estimators; (2) stroke length at V4 (SL@V4) and stroke frequency at V4 (SF@V4), as biomechanical variables. The results demonstrated no significant variations in all variables throughout the season. The inter-group comparison pointed out higher values for Int swimmers, with statistical differences for the 200 m performance in all time periods. Near values of the statistical significance were demonstrated for the SI@V4 in TP(1) and TP(3). The tracking based on K values was high only for the SI@V4. It is concluded that a high stability can be observed for elite swimmers performance, energetic and biomechanical profiles throughout a single season. Int swimmers are able to maintain a higher energetic and biomechanical capacity than Nat ones at all times. The SI@V4 may be used as an indicator of performance variation.

The Effect of Handlebar Height and Bicycle Frame Length on Muscular Activity during Cycling: A Pilot Study.

The cycling literature is filled with reports of electromyography (EMG) analyses for a better understanding of muscle function during cycling. This research is not just limited to performance, as the cyclist's goal may be rehabilitation, recreation, or competition, so a bicycle that meets the rider's needs is essential for a more efficient muscular activity. Therefore, the purpose of this study was to understand the contribution of the activity of each of the following muscles: TD (trapezius descending), LD (latissimus dorsi), GM (gluteus maximus), and AD (anterior deltoid) in response to different bicycle-rider systems (handlebar height; bicycle frame length) and intensities in a bicycle equipped with a potentiometer. Surface EMG signals from muscles on the right side of the body were measured. A general linear model test was used to analyze the differences between muscle activation in the test conditions. Effect sizes were calculated using a partial Eta2 (η2). The level of significance was set at 0.05. Muscle activation of different muscles differs, depending on the cycling condition (Pillai's trace = 2.487; F (36.69) = 9.300; p < 0.001. η2 = 0.958), mostly during low intensities. In high intensities, one specific pattern emerges, with a greater contribution of GM and TD and weaker participation of LD and AD, enhancing the cycling power output.

Profile of Whole Body Electromyostimulation Training Users-A Pilot Study.

(1) Introduction: Whole Body Electromyostimulation is a technological and time efficient personal training practiced all over the world. With the increase of practitioners in the last 10 years, the need to study more about practitioners has arisen, so this pilot study aims to trace a user profile of this method through the analysis of socio-demographic data for a better understand of the profile of people looking for this type of training to improve the effectiveness of the intervention and develop programs that are in accordance with the motivation of practitioners. (2) Methods: 270 users from 5 countries answered an online questionnaire with socio-demographic questions. Data were treated using descriptive statistics. Possible differences between sexes and between groups were analyzed by means of non-parametric statistical tests: Mann−Whitney U-test (continuous variables); in addition to studying possible dependence relationships and differences between proportions, using the Chi-square statistic with pairwise z-test using the Bonferroni correction (categorical variables). (3) Results: Middle-aged women are the main user of this type of training. The majority of WB-EMS users do another type of physical activity with significant difference between men and woman (p < 0.05) men are more active than women. Weight loss, health and wellness and muscle mass increase are the main goals of the WB-EMS users. There are significant differences in weight loss and rehabilitation between genders (p < 0.05). Women look much more than men to lose weight and men look more than women to rehabilitation. (4) Conclusions: The user profile is a physically active woman, aged 35−49 years, with normal weight and high educational level, who carries out twice weekly full body electrostimulation training with the goals of weight loss, health and/or wellness and muscle mass gain.

Bibliometric Analysis of Studies on Whole Body Electromyostimulation.

Whole Body Electromyostimulation [WB-EMS] is a training methodology that applies electrostimulation in the main muscle groups of the human body superimposed with active training exercises. This study aims to carry out a bibliometric analysis on WB-EMS to provide an overview of the state of research and provide new insights for research in the field. METHOD: One hundred and two citations extracted were examined using a bibliometric approach based on data stored in the Web of Science Core Collection, applying traditional bibliometric laws, and using VOSviewer and excel for data and metadata processing. RESULTS: Among the results, this study points out that Germany is the country that produces more scientific knowledge on WB-EMS. Wolfgang Kemmler is the most relevant author in this field. Moreover, Frontier of Physiology is the journal where the authors publish the most. CONCLUSION: Research on WB-EMS has been growing in recent years. German and Spanish researchers lead two clusters where most studies and collaborations in this field are carried out. These findings will provide a better understanding of the state of WB-EMS research and may guide the emergence of new lines of investigation and research ideas.

Three-Month vs. One-Year Detraining Effects after Multicomponent Exercise Program in Hypertensive Older Women.

Background: Chronic diseases are the leading causes of death and disability in older women. Physical exercise training programs promote beneficial effects for health and quality of life. However, exercise interruption periods may be detrimental for the hemodynamic and lipidic profiles of hypertensive older women with dyslipidemia. Methods: Nineteen hypertensive older women with dyslipidemia (exercise group: 67.5 ± 5.4 years, 1.53 ± 3.42 m, 71.84 ± 7.45 kg) performed a supervised multicomponent exercise training program (METP) during nine months, followed by a one-year detraining period (DT), while fourteen hypertensive older women (control group: 66.4 ± 5.2 years, 1.56 ± 3.10 m, 69.38 ± 5.24 kg) with dyslipidemia kept their continued daily routine without exercise. For both groups, hemodynamic and lipidic profiles and functional capacities (FCs) were assessed four times: before and after the METP and after 3 and 12 months of DT (no exercise was carried out). Results: The METP improved hemodynamic and lipidic profiles (p < 0.05), while three months of DT decreased all (p < 0.05) parameters, with the exception of diastolic blood pressure (DBP). One year of DT significantly (p < 0.01) decreased systolic blood pressure (7.85%), DBP (2.29%), resting heart rate (7.95%), blood glucose (19.14%), total cholesterol (10.27%), triglycerides (6.92%) and FC­agility (4.24%), lower- (−12.75%) and upper-body strength (−12.17%), cardiorespiratory capacity (−4.81%) and lower- (−16.16%) and upper-body flexibility (−11.11%). Conclusion: Nine months of the exercise program significantly improved the hemodynamic and lipid profiles as well as the functional capacities of hypertensive older women with dyslipidemia. Although a detraining period is detrimental to these benefits, it seems that the first three months are more prominent in these alterations.

Can Exercise Help Regulate Blood Pressure and Improve Functional Capacity of Older Women with Hypertension against the Deleterious Effects of Physical Inactivity?

BACKGROUND: Sedentarism and inactivity are risk factors for the development of hypertension. Thus, the prevention of the natural process of biological and physiological aging of older women through physical exercise results in higher benefits in preventing cardiovascular diseases and can be a key factor for its treatment. Multicomponent exercise (METP) is a training method that may help older women with hypertension by improving their quality of life and their response to treatment. METHODS: Twenty-eight older Caucasian women with hypertension (66.7 ± 5.3 years, 1.59 ± 0.11 m) performed a supervised METP program of nine months followed by three months of detraining (DT), and seventeen older women (68.2 ± 4.7 years, 1.57 ± 0.16 cm) with hypertension maintained their daily routine, without exercise. Blood pressure (BP), resting heart rate, and functional capacity (FC) were evaluated at the beginning and at the end of the program, and after three months of DT. RESULTS: The ME program improved (p < 0.05) systolic BP (-5.37%), diastolic BP (-5.67%), resting heart rate (-7.8%), agility (9.8%), lower body strength (27.8%), upper body strength (10.0%), and cardiorespiratory capacity (8.6%). BP and FC deteriorated after the DT period (p < 0.05). CONCLUSION: Nine months of multicomponent exercise were sufficient to improve functional capacity and promote benefits in blood pressure, although was not sufficient to allow BP to reach the normal values of older women. The three month DT period without exercise caused the reversal of BP improvements but maintained the functional capacity of older women.

The Acute Effects of a Swimming Session on the Shoulder Rotators Strength and Balance of Age Group Swimmers.

The purpose of this study was to analyze the acute effects of a standardized water training session on the shoulder rotators strength and balance in age group swimmers, in order to understand whether a muscle-strengthening workout immediately after the water training is appropriate. A repeated measures design was implemented with two measurements performed before and after a standardized swim session. 127 participants were assembled in male (n = 72; age: 16.28 ± 1.55 years, height: 174.15 ± 7.89 cm, weight: 63.97 ± 6.51 kg) and female (n = 55; age: 15.29 ± 1.28 years, height: 163.03 ± 7.19 cm, weight: 52.72 ± 5.48 kg) cohorts. The isometric torque of the shoulder internal (IR) and external (ER) rotators, as well as the ER/IR ratios, were assessed using a hand-held dynamometer. Paired sample t-tests and effect sizes (Cohen's d) were used (p ≤ 0.05). No significant differences were found on the shoulder rotators strength or balance in males after training. Females exhibited unchanged strength values after practice, but there was a considerable decrease in the shoulder rotators balance of the non-dominant limb (p < 0.01 d = 0.366). This indicates that a single practice seems not to affect the shoulders strength and balance of adolescent swimmers, but this can be a gender specific phenomenon. While muscle-strengthening workout after the water session may be appropriate for males, it can be questionable regarding females. Swimming coaches should regularly assess shoulder strength levels in order to individually identify swimmers who may or may not be able to practice muscle strengthening after the water training.

Multicomponent Exercise Program for Improvement of Functional Capacity and Lipidic Profile of Older Women with High Cholesterol and High Triglycerides.

BACKGROUND: Physical inactivity is a primary cause of most chronic diseases. In addition, the negative effects of aging, physical inactivity and dyslipidemia are risk factors for cardiovascular diseases of older women. Exercise is considered fundamental for the treatment and prevention due to the benefits in the health of this population, but detraining periods after exercise can reverse them. Multicomponent exercise (ME) is a combined method of aerobic and resistance training that can improve the lipidic profile of older women with high cholesterol and triglycerides. METHODS: Seventeen older women (EG: 65.3 ± 4.7 years, 1.52 ± 4.12 m) followed a supervised ME program of nine months and three months of detraining (DT), and fifteen older women (CG: 66.4 ± 5.2 years, 1.54 ± 5.58 cm) continued their daily routine, without exercise. Total cholesterol (TC), triglycerides (TG), blood glucose (GL) and functional capacity (FC) were evaluated at the beginning and at the end of the program and after three months of DT. RESULTS: ME program improved (p < 0.05) lipidic profile: GL (-15.6%), TC (-15.3%), TG (-19.3%) and FC: agility (-13.3%), lower body strength (27.78%), upper body strength (26.3%), cardiorespiratory capacity (11.2%), lower body flexibility (66.67%) and upper body flexibility (85.72%). DT declined the lipidic profile and FC (p < 0.05). CONCLUSION: Lipidic profile and functional capacity can be improved with nine months of ME. Besides the negative effects of DT, three months were not enough to reverse the benefits of exercise in older women with high values of TG and TC.

The effects of whole-body muscle stimulation on body composition and strength parameters: A protocol for systematic review and meta-analysis.

BACKGROUND: This study will analyze the effect of Whole Body Electromyostimulation (WB-EMS) in strength and body composition outcomes in adult population. METHODS: This study will search the following electronic databases up to July 21, 2020: PubMed, WOS, Scopus, SPORTDiscus y EMBASE. There will be no language limitation. Two authors will independently identify titles/abstracts and full text all potential studies, and will collect data from eligible studies. Additionally, study quality will be assessed by PEDro Scale risk of bias. We will conduct meta-analysis if enough trials are included. RESULTS: This study will explore the effects of WB-EMS in strength and body composition outcomes. CONCLUSION: The findings of this study may summarize the effectiveness of WB-EMS in increasing strength and improving body composition in adult population. INPLASY REGISTRATION NUMBER: INPLASY202120050.

COMT genotype affects prefrontal white matter pathways in children and adolescents.

Diffusion tensor imaging is widely used to evaluate the development of white matter. Information about how alterations in major neurotransmitter systems, such as the dopamine (DA) system, influence this development in healthy children, however, is lacking. Catechol-O-metyltransferase (COMT) is the major enzyme responsible for DA degradation in prefrontal brain structures, for which there is a corresponding genetic polymorphism (val158met) that confers either a more or less efficient version of this enzyme. The result of this common genetic variation is that children may have more or less available synaptic DA in prefrontal brain regions. In the present study we examined the relation between diffusion properties of frontal white matter structures and the COMT val158met polymorphism in 40 children ages 9-15. We found that the val allele was associated with significantly elevated fractional anisotropy values and reduced axial and radial diffusivities. These results indicate that the development of white matter in healthy children is related to COMT genotype and that alterations in white matter may be related to the differential availability of prefrontal DA. This investigation paves the way for further studies of how common functional variants in the genome might influence the development of brain white matter.

Neural circuitry of emotional face processing in autism spectrum disorders.

BACKGROUND: Autism spectrum disorders (ASD) are associated with severe impairments in social functioning. Because faces provide nonverbal cues that support social interactions, many studies of ASD have examined neural structures that process faces, including the amygdala, ventromedial prefrontal cortex and superior and middle temporal gyri. However, increases or decreases in activation are often contingent on the cognitive task. Specifically, the cognitive domain of attention influences group differences in brain activation. We investigated brain function abnormalities in participants with ASD using a task that monitored attention bias to emotional faces. METHODS: Twenty-four participants (12 with ASD, 12 controls) completed a functional magnetic resonance imaging study while performing an attention cuing task with emotional (happy, sad, angry) and neutral faces. RESULTS: In response to emotional faces, those in the ASD group showed greater right amygdala activation than those in the control group. A preliminary psychophysiological connectivity analysis showed that ASD participants had stronger positive right amygdala and ventromedial prefrontal cortex coupling and weaker positive right amygdala and temporal lobe coupling than controls. There were no group differences in the behavioural measure of attention bias to the emotional faces. LIMITATIONS: The small sample size may have affected our ability to detect additional group differences. CONCLUSION: When attention bias to emotional faces was equivalent between ASD and control groups, ASD was associated with greater amygdala activation. Preliminary analyses showed that ASD participants had stronger connectivity between the amygdala ventromedial prefrontal cortex (a network implicated in emotional modulation) and weaker connectivity between the amygdala and temporal lobe (a pathway involved in the identification of facial expressions, although areas of group differences were generally in a more anterior region of the temporal lobe than what is typically reported for emotional face processing). These alterations in connectivity are consistent with emotion and face processing disturbances in ASD.

Stability of patterns of behavior in the butterfly technique of the elite swimmers.

The purpose of this study was to find patterns in the butterfly swimming technique, with an adaptation of the Behavioral Observation System Tech. This, as an instrument for ad-hoc qualitative analysis, enables the study of the stability of the technical implementation. When used in the training of swimmers, analysis can reduce the variability of behavioral tuning swimming technique. Through the analysis of temporal patterns (T-pattern) and a sequence of five cycles running at hand maximum speed, the behavior of four technical Portuguese elite swimmers, with a record of 259 alphanumeric codes and a total of 160 configurations, were studied. The structure of the original instrument, based on a mixed system of categories and formats Field, can record technical features, observed during the execution of hand cycles. The validity was ensured through the index of intra-observer reliability (95%) and inter-observer accuracy (96%). To detect patterns in each swimmer, the Theme 5.0 software was used, which allowed to identify the stable structures of technical performance within a critical interval of time (p <0.05) - t-patterns. The patterns were different, adjusting to the characteristics of technical implementation of the swimmers. It was found that the swimmer can create settings with different levels of structure complexity, depending on the implementation of changes within the hand cycle. Variations of codes in each configuration obtained using the SOCTM, allowed determining the differences between swimmers. However, the records showed a clear behavioral similarity when comparing the result with a general pattern of the butterfly technique. The potential quality of this instrument seems to be important due to the patterns obtained from a temporal sequence. Key pointsThe patterns were different, adjusting to the characteristics of technical implementation of the swimmers.The swimmer can make settings with different levels of structure complexity, depending on the implementation of changes within the hand cycle.Variations of codes in each configuration obtained using the SOCTM, allowed determining the differences between swimmers.The records showed a clear behavioral similarity when comparing the result with a general pattern of the butterfly technique.The potential quality of this instrument seems to be important due to the patterns obtained from a temporal sequence.

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.

Estimating time-to-contact with temporal occlusion in relay swimming: a pilot study.

The purpose of this study was to analyse swimmers' perceptual judgements of a simulated time-to-contact task in freestyle swimming relays. The study sample consisted of 31 national-level swimmers of both genders (n = 18 males, 17.22 ± 1.95 yrs.; n = 13 females, 14.61 ± .76 yrs.). Participants were asked to watch two videos corresponding to the last course of a given swimmer during a competition of 4 × 100 m and 4 × 200 m freestyle events. These videos were presented with temporal occlusion correspondent to predetermined approaching distances (7.5, 5.0, and 2.5 m). Participants were required to simulate a typical position in standby for exiting the block and estimate the time-to-contact of the incoming swimmer by pressing a switch. A Wilcoxon test was performed to determine differences between time-to-contact and real contact time. The results showed that estimation of time-to-contact was generally lower than real contact time at all approaching distances (with occlusion) and for both genders (p < .05), except at a 7.5-m distance in the men's 4 × 200 m (p = .744; r = .09) and at 5.0 m in both the 4 × 100 m and 4 × 200 m for the female group (p = .279, r = .22 for 4 × 100 m; p = .2453, r = .17 for 4 × 200 m). The larger variation (Δ) between estimation and real contact time was found at a 7.5 m occlusion distance in the female 4 × 100 m (p < .001; r = .82). Swimmers tend to underestimate the time-to-contact of the incoming swimmer, in the context of a simulated relay race. Taken together, these results highlight the importance of perceptual abilities development in swimmers to optimize their technique and effectiveness during relay starts.

Association between ACE D allele and elite short distance swimming.

The influence of ACE gene on athletic performance has been widely explored, and most of the published data refers to an I/D polymorphism leading to the presence (I allele) or absence (D allele) of a 287-bp sequence in intron 16, determining ACE activity in serum and tissues. A higher I allele frequency has been reported among elite endurance athletes, while the D allele was more frequent among those engaged in more power-orientated sports. However, on competitive swimming, the reproducibility of such associations is controversial. We thus compared the ACE genotype of elite swimmers with that of non-elite swimming cohort and of healthy control subjects. We thus sought an association of the ACE genotype of elite swimmers with their competitive distance. 39 Portuguese Olympic swimming candidates were classified as: short (<200 m) and middle (400-1,500 m) distance swimmers, respectively. A group of 32 non-elite swimmers were studied and classified as well, and a control group (n = 100) was selected from the Portuguese population. Chelex 100 was used for DNA extraction and genotype was determined by PCR-RFLP methods. We found that ACE genotype distribution and allelic frequency differs significantly by event distance only among elite swimmers (P < or = 0.05). Moreover, the allelic frequency of the elite short distance swimmers differed significantly from that of the controls (P = 0.021). No associations were found between middle distance swimmers and controls. Our results seem to support an association between the D allele and elite short distance swimming.

Angiotensin-converting enzyme genotype affects skeletal muscle strength in elite athletes.

Previous studies have associated angiotensin-converting enzyme (ACE) D allele with variability in the skeletal muscle baseline strength, though conclusions have been inconsistent across investigations. The purpose of this study was to examine the possible association between ACE genotype and skeletal muscle baseline strength in elite male and female athletes involved in different event expertise. A group of 58 elite athletes, designated as Olympic candidates, were studied: 35 swimmers (19 males and 16 females, 18.8 ± 3.2 years) and 23 triathletes (15 males and 8 females, 18.7 ± 3.0 years). The athletes were classified as: short (≤ 200m) and middle (400m to 1500m) distance athletes, respectively. For each subject the grip strength in both hands was measure using an adjustable mechanical hand dynamometer. The maximum height in both squat jump (SJ) and counter movement jump (CMJ) were also assessed, using a trigonometric carpet (Ergojump Digitime 1000; Digitest, Jyvaskyla, Finland). DNA extraction was obtained with Chelex 100(®) and genotype determination by PCR-RFLP methods. Both males and females showed significantly higher right grip strength in D allele carriers compared to II homozygote's. We found that allelic frequency differs significantly by event distance specialization in both genders (p < 0.05). In fact, sprinter D allele carriers showed the superior scores in nearly all strength measurements (p < 0.05), in both genders. Among endurance athletes, the results also demonstrated that female D allele carriers exhibited the higher performance right grip and CMJ scores (p < 0.05). In conclusion, the ACE D allele seems associated with skeletal muscle baseline strength in elite athletes, being easily identified in females. Key pointsDD homozygote's and D allele carriers from both genders shows significantly higher right grip strength.Right grip strength remains significantly higher in the D allele carrier's female endurance group.Female's D allele carriers exhibited the higher performance counter-movement jump scores.ACE genotype effects in skeletal-muscle strength are diverse by gender, being easily identified in females.