35 research outputs found

    Les changements liés à l'âge et la différence de sexe dans la performance de natation chez les athlètes seniors

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    Master athletes have been widely used to examine the age-induced decline of human performance. However, so far very limited reviews are available consolidating the age-related differences in master swimming performance. The aim of the present review was to summarize existing knowledge about the age-related changes in three modalities of swimming performance (i.e., pool-swimming, open-water swimming and swim split in triathlons of different distances). In addition, the paradigm of freestyle swimming records from 50 to 1500mwas used to examine age-related differences and sex difference in performance for age groups 25–29 to 100–104 years. For this example of master freestyle swimmers, the sex difference was smaller in the longer events and increased significantly after the age of ∼70 years. In summary, master athletes competing in swimming as single discipline (i.e., pool-swimming and open-water) and in triathlon (i.e., swim split as first discipline) improved their performances across calendar years. The age-related performance decline in swimming seems to be specific to the discipline, the sex and the length of the swimming event.Les changements liés à l’âge et la différence de sexe dans la performance de natation chez les athlètes seniors. Les athlètes seniors ont été largement utilisés pour examiner le déclin de la performance humaine induit par l’âge. Cependant, à ce jour, des études très limitées sont disponibles, consolidant les différences de performances de nage des seniors liées à l’âge. Le but de la présente étude était de résumer les connaissances existantes sur les changements liés à l’âge de trois modalités de performance en natation (à savoir, la natation en piscine, la nage en eau libre et la natation divisée en triathlons de différentes distances). De plus, le cas des records de nage libre de 50 à 1500ma été utilisé pour examiner les différences liées à l’âge et la différence de performance entre les sexes pour les groupes d’âge partant de 25 à 29 ans jusqu’à 100 à 104 ans. En ce qui concerne le cas des nageurs seniors en eau libre, la différence de sexe était plus petite dans les épreuves plus longues et augmentait significativement après l’âge de 70 ans. En résumé, les athlètes seniors pratiquant la natation en tant que discipline unique (c’est-à-dire la natation en piscine et en eau libre) et le triathlon (c’est-àdire la division en natation comme première discipline) ont amélioré leurs performances au fil des années. La baisse de performance liée à l’âge en natation semble être spécifique à la discipline, au sexe et à la durée de la nage.info:eu-repo/semantics/publishedVersio

    Analysis of cyclist's drag on the aero position using numerical simulations and analytical procedures: a case study

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    Background: Resistance acting on a cyclist is a major concern among the cycling fraternity. Most of the testing methods require previous training or expensive equipment and time-consuming set-ups. By contrast, analytical procedures are more affordable and numerical simulations are perfect for manipulating and controlling inputs. The aim of this case study was to compare the drag of a cyclist in the aero position as measured using numerical simulation and analytical procedures. Methods: An elite male cyclist (65 kg in mass and 1.72 m in height) volunteered to take part in this research. The cyclist was wearing his competition gear, helmet and bicycle. A three-dimensional model of the bicycle and cyclist in the aero position was obtained to run the numerical simulations. Computational fluid dynamics (CFD) and a set of analytical procedures were carried out to assess drag, frontal area and drag coefficient, between 1 m/s and 22 m/s, with increments of 1 m/s. The t-test paired samples and linear regression were selected to compare, correlate and assess the methods agreement. Results: No significant differences (t = 2.826; p = 0.275) between CFD and analytical procedures were found. The linear regression showed a very high adjustment for drag (R2 = 0.995; p < 0.001). However, the drag values obtained by the analytical procedures seemed to be overestimated, even though without effect (d = 0.11). Conclusions: These findings suggest that drag might be assessed using both a set of analytical procedures and CFD.This work is supported by national funds (FCT-Portuguese Foundation for Science and Technology under the project UIDB04045/2020) and The APC was funded by Research Center in Sports Health and Human Development, Covilhã, Portugal.info:eu-repo/semantics/publishedVersio

    Sex differences in swimming disciplines—can women outperform men in swimming?

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    In recent years, the interest of female dominance in long-distance swimming has grown where several newspaper articles have been published speculating about female performance and dominance—especially in open-water ultra-distance swimming. The aim of this narrative review is to review the scientific literature regarding the difference between the sexes for all swimming strokes (i.e., butterfly, backstroke, breaststroke, freestyle and individual medley), di erent distances (i.e., from sprint to ultra-distances), extreme conditions (i.e., cold water), different ages and swimming integrated in multi-sports disciplines, such as triathlon, in various age groups and over calendar years. The influence of various physiological, psychological, anthropometrical and biomechanical aspects to potentially explain the female dominance was also discussed. The data bases Scopus and PUBMED were searched by April 2020 for the terms ’sex–difference–swimming’. Long-distance open-water swimmers and pool swimmers of different ages and performance levels were mainly investigated. In open-water long-distance swimming events of the ’Triple Crown of Open Water Swimming’ with the ’Catalina Channel Swim’, the ’English Channel Swim’ and the ’Manhattan Island Marathon Swim’, women were about 0.06 km/h faster than men. In master swimmers (i.e., age groups 25–29 to 90–94 years) competing in the FINA (Fédération Internationale de Natation) World Championships in pool swimming in freestyle, backstroke, butterfly, breaststroke, individual medley and in 3000-m open-water swimming, women master swimmers appeared able to achieve similar performances as men in the oldest age groups (i.e., older than 75–80 years). In boys and girls aged 5–18 years—and listed in the all-time top 100 U.S. freestyle swimming performances from 50 m to 1500 m—the five fastest girls were faster than the five fastest boys until the age of ~10 years. After the age of 10 years, and until the age of 17 years, however, boys were increasingly faster than girls. Therefore, women tended to decrease the existing sex differences in specific age groups (i.e., younger than 10 years and older than 75–80 years) and swimming strokes in pool-swimming or even to overperform men in long-distance open-water swimming (distance of ~30 km), especially under extreme weather conditions (water colder than ~20º C). Two main variables may explain why women can swim faster than men in open-water swimming events: (i) the long distance of around 30 km, (ii) and water colder than ~20 C. Future studies may investigate more detailed (e.g., anthropometry) the very young (75–80 years) age groups in swimming.info:eu-repo/semantics/publishedVersio

    Kinematic and neuromuscular measures of intensity during drop jumps in female volleyball players

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    The aim of this study was to assess drop jump (DJ) performance variables (jump height, contact time, and reactive strength index) concomitant to surface electromyography (sEMG) of lower limb muscles during DJs from different drop heights (intensities). The eccentric and concentric phase sEMG from the gastrocnemius medialis, biceps femoris, and vastus medialis muscles were assessed during all tests, with sEMG activity normalized to maximal voluntary isometric contraction (MVIC). In a cross-sectional, study, 10 amateur female volleyball players (age 22.1 ± 1.8 years; body mass 72.9 ± 15.2 kg; height 1.70 ± 0.08 m) completed DJs from six heights [15-90 cm (DJ15 to DJ90)]. During DJs there was no jump-target box to rebound on to. Results of one-way analysis of variance (ANOVA) showed that the jump height, contact time, and reactive strength index were not significantly ( \u3e 0.05) different between drop heights. Mean biceps femoris eccentric and concentric sEMG ranged from 27 to 50%, although without significant differences between drop heights. Mean gastrocnemius medialis eccentric and concentric sEMG remained relatively constant (∼60-80% MVIC) across DJs heights, although eccentric values reached 90-120% MVIC from DJ75 to DJ90. Mean variations of ∼50-100% MVIC for eccentric and ∼50-70% MVIC for concentric sEMG activations were observed in the vastus medialis across DJs heights. The biceps femoris eccentric/concentric sEMG ratio during DJ45 (i.e., 1.0) was lower ( = 0.03) compared to the ratio observed after DJ90 (i.e., 3.2). The gastrocnemius medialis and vastus medialis eccentric/concentric sEMG ratio were not significantly different between drop heights. In conclusion, jumping performance and most neuromuscular markers were not sensitive to DJ height (intensity) in amateur female volleyball athletes

    Anthropometric profile of soccer players as a determinant of position specificity and methodological issues of body composition estimation

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    The aim of the present study was (a) to describe the anthropometric profile of a large group of soccer players based on different age groups and their playing positions on the field, and (b) to examine the variations of body composition among adult soccer players using diverse equations based on skinfold thickness. A total of 618 Greek soccer players who were grouped by age (i.e.,12?14, 14?16, 16?18, and 18?37 years) and playing position (i.e., goalkeeper, defender, midfielder, and forward) were evaluated for weight, height, and skinfolds. The Pa?r?zkov? formula was used to estimate the percentage of body fat. Furthermore, for players who were 18 years or older the Reilly and Evans formulas was used to estimate the percentage of body fat. Independent of the age, in this large sample, goalkeepers presented higher values for weight, height and the percentage of body fat estimation as compared with other field positions. An anthropometric pattern was observed in each tactical position, namely, across a specific age of increasing maturation process (14?16 years). With the Pa?r?zkov? formula, we found a mean (SD) range of variation in the percentage of body fat estimation between 4.87 ? 1.46 and 5.51 ? 1.46 as compared with the Evans formula. The same pattern of differences was found when the Reilly equation was considered. In conclusion, we observed a position specificity of anthropometric characteristics across different age categories. Additionally, the same data supported different validated equations which resulted in large differences in the final outcome estimations.D915-7373-ED16 | Cesar LeaoN/

    A machine learning approach to finding the fastest race course for professional athletes competing in Ironman® 70.3 races between 2004 and 2020

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    Our purpose was to find the fastest race courses for elite Ironman® 70.3 athletes, using machine learning (ML) algorithms. We collected the data of all professional triathletes competing between 2004 and 2020 in Ironman 70.3 races held worldwide. A sample of 16,611 professional athletes originating from 97 different countries and competing in 163 different races was thus obtained. Four different ML regression models were built, with gender, country of origin, and event location considered as independent variables to predict the final race time. For all the models, gender was the most important variable in predicting finish times. Attending to the single decision tree model, the fastest race times in the Ironman® 70.3 World Championship of around ~4 h 03 min would be achieved by men from Austria, Australia, Belgium, Brazil, Switzerland, Germany, France, the United Kingdom, South Africa, Canada, and New Zealand. Considering the World Championship is the target event for most professional athletes, it is expected that training is planned so that they attain their best performance in this event.info:eu-repo/semantics/publishedVersio

    Motivation for Brazilian Older Adult Women to Join a Community Physical Activity Program Before COVID-19 Pandemic

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    Background: Intrinsic and extrinsic motivational factors can affect the levels of adherence of physical activity (PA) during the aging process. Objectives: Investigate the intrinsic and extrinsic aspects and motivation that led older women to enroll in and adhere to a community PA program before the COVID-19 pandemic. Methods: Data were collected via transversal survey before the COVID-19 pandemic. The sample consisted of 21 women, participants of a PA workshop, aged between 60 to 86 years [< 1-year (n = 8) and ≥ 1-year (n = 13) groups]. Motivation was assessed by the Motivation Inventory for Regular Physical Activity Practice (IMPRAF-54), using the 60th percentile to categorize high and low motivation, and two open questions. For qualitative assessment, content analysis was used and the answers were framed into subcategories regarding the motivation factors for adherence and permanence. Results: That adherence to the program was motivated by sociability purposes [total score: 36.0 (6.0), median (interquartile range)] and pleasure [34.0; (6.0)], while the main motivation for permanence was health [40.0 (11.0)]. Differences were noticed between the groups for sociability [38.0 (3.0) P = 0.030] and competitiveness [9.50 (12.0); P = 0.037] highest medians for the < 1 year group. Furthermore, the factors that least motivated older women were competitiveness and aesthetics. Conclusions: Health and sociability were the main motivators for the practice of physical activity among older adult women. Motivation played a fundamental role in the permanence of older adult women in the physical activity program

    Analysis of Grip Amplitude on Velocity in Paralympic Powerlifting

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    (1) Background: Paralympic Powerlifting (PP) is a Paralympic modality that is predominantly about developing maximal force, as there are athletes who lift three times their body weight. Our objective was to evaluate the averages of the velocity for 30% and 50% of 1 Maximum Repetition (1 RM) on different amplitudes of the footprint in PP athletes; (2) Methods: The intervention happened over two weeks, with the first being devoted to the familiarization and testing of 1 RM, while in the second week, through the use of a linear Encoder, tests of velocity average (VA), velocity average propulsive (VAP), and velocity peak (VP) were carried out with loads of 30% and 50% of a maximum repetition 1 RM for 1× of the biacromial distance (BAD) 1.3 × BAD, 1.5 × BAD; (3) Results: There was a significant difference in the average velocity of 1 × BAD (1.16 ± 0.14 m/s, 1.07–1.26 IC; η2p 0.20) when compared to 1.3 × BAD (1.00 ± 0.17 m/s, 0.90–1.09 IC; η2p 0.20) over 30% of 1 RM. For the other velocity variables for 30% and 50% of 1 RM with different grip amplitudes, there were no significant differences; (4) Conclusions: In PP, the 1 × BAD footprint contributes significantly to VA at 30% of 1 RM when compared to the 1.3 × BAD and 1.5 × BAD footprints. For loading at 50% of 1 RM the VA, VAP and VP decreased when compared to 30% of 1 RM, to the extent that the VAP and VP generated with the 1.3 × BAD and 1.5 × BAD footprints were higher than those with 1 × BAD, other than for VA 50% of 1 RM, where the 1 × BAD footprint was superior to the others

    Body mass index and body fat percentage are associated with decreased physical fitness in adolescent and adult female volleyball players

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    Background: The objectives of this study were to examine (a) the prevalence of overweight/obesity, and (b) the relationship between body mass index (BMI), body fat percentage (BF) and physical fitness in adolescent and adult female volleyball players. Materials and Methods: Adolescent (n = 102, aged 15.2 ± 2.0 year) and adult (n = 57, 25.9 ± 5.0 year) players were examined for anthropometric characteristics and body composition, and performed the physical working capacity in heart rate 170 min -1 test, a force-velocity test, the Wingate anaerobic test (WAnT), sit-and-reach test (SAR), handgrip strength test (HST) and countermovement vertical jump (CVJ). Results: Based on international BMI cut-off points, 27.5% (n = 28) of adolescent and 12.3% (n = 7) of adult participants were classified as overweight, with the prevalence of overweight being higher in girls than in women (χ2 = 4.90, P = 0.027). BMI was correlated with BF in both age groups (r = 0.72, P < 0.001 in girls; r = 0.75, P < 0.001 in women). Normal participants had superior certain physical and physiological characteristics than those who were overweight. For instance, normal girls and women had higher mean power during WAnT than their overweight counterparts (P = 0.003 and P = 0.009 respectively). Except for flexibility, BMI and BF were inversely related with physical fitness (e.g., BMI vs. HST r = -0.39, P < 0.001 in girls; BF vs. CVJ r = -0.45, P < 0.001 in women). Conclusion: The findings confirmed the negative effect of overweight and fatness on selected parameters of physical fitness. The prevalence of overweight in adolescent volleyball players was higher than in general population, which was a novel finding, suggesting that proper exercise interventions should be developed to target the excess of body mass in youth volleyball clubs
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