100-m Freestyle Research Articles

Do Thirty-Second Post-activation Potentiation Exercises Improve the 50-m Freestyle Sprint Performance in Adolescent Swimmers?

Objectives: The purpose of the study was to investigate performance, biomechanical, physiological, and psychophysiological effects of a simple and easily organized post-activation potentiation (PAP) re-warm-up performed before a 50-m freestyle swimming sprint.Methods: Regional level male adolescent swimmers [age: 13.0 ± 2.0 years; (min 11 years – max 15 years)] performed four trial conditions (three experimental, one control) on different days. The control trial involved a standardized 1200-m warm-up followed by 30 min of rest and a maximal 50-m freestyle swimming sprint. The experimental trials involved the same protocol but added a PAP component after a 20-min rest (10 min pre-50-m): The different PAP component involved the subjects in completing a 30-s maximal effort of: (1) push-ups (PU – upper body), (2) squats (SQ – lower body), and (3) burpees (BP – lower and upper body). Performance (time-trial), biomechanical (stroke length, stroke frequency), physiological (blood lactate concentrations, heart rate), and psychophysiological (ratings of perceived exertion) variables were collected.Results: The results demonstrated that the PAP protocols used in this investigation had no effect on swimming performance. Before the 50-m swimming sprint, the lactate values were significantly higher after the PU, BP, and SQ PAP loads compared to the control condition [P(CC-PU) = 0.02; P(CC-BP) = 0.01; P(CC-SQ) = 0.04]. For Lactate values, a significant and large effect of experimental condition compared to control condition was found (p < 0.05, η2 = 0.68). At 1 min after the 50-m time trial, significant differences were observed between the control condition and the different PAP loads [P(CC-PU) = 0.01; P(CC-BP) = 0.04; P(CC-SQ) = 0.01]. At 3 min after the 50-m sprint, significant differences were found between the control condition and the PU and SQ PAP loads [P(CC-PU) = 0.018; P(CC-SQ) = 0.008, respectively]. Additionally, a significant and large effect of experimental condition was found at 1 and 3 min after the 50-m swimming sprint (p < 0.05, η2(1 min) = 0.73; η2(3 min) = 0.59). There were medium sized but non-significant effects of interaction between the conditions, was illustrated for the mean HR values in response to the different conditions (p > 0.05; η2 = 0.083).Conclusion: None of the three PAP protocols showed any significant improvement in performance, biomechanical, physiological, and psychophysiological variables before, during and after the 50-m swimming time-trial. Further studies are warranted to investigate ways to improve swimming performance with simple body mass exercises performed in-between the end of pool warm-up and race start.

Laboratory Assessments and Field Tests in Predicting Competitive Performance of Swimmers

Research background and hypothesis. The assessments of functional fitness of swimmers includes the analyses of the physical, physiological and biomechanical indices for scientific purposes. The hypothesis is that dynamical parameters registered while performing field testing tasks could be more informative than laboratory assessments in predicting the performance abilities. The aim of the study was to compare the informativeness of field tests and laboratory assessments in predicting the possible performance of athletes in the 50 m distance.Research methods. Twelve professional swimmers took part in three testing procedures. First, each participant performed a test in water to establish the traction force parameters and indices of muscle power and anaerobic capacity. Second, the subjects performed a control 50 m freestyle swim the best they could. Third, the indices of relative muscle power during jumping tasks, anaerobic capacity, and functional indices of cardiovascular system were assessed during laboratory testing.Research results. Significant correlation was found between the results in 50 m swimming and traction forces while performing testing tasks in water or out of water with arms or arms and legs together. However, there was no statistically significant correlation between the results in swimming and the height of vertical jump. Still there exists significant correlation (p &lt; 0.05) between the speed and force components as well as fatigability index and the competition result (r = –0.47; r = 0.56 and r = 0.67, respectively).Discussion and conclusions. Dynamical parameters measured in the swimming pool while performing field tests are more suitable than the data of laboratory research for predicting the results of swimmers in the 50m freestyle swim. The vertical high jump tests and indices of ECG allow distinguishing the factors limiting the working capacity of athletes.Keywords: swimming, functional fitness, field test.

Modelling stroking parameters in competitive sprint swimming: Understanding inter- and intra-lap variability to assess pacing management

This study investigated the inter- and intra-lap variability in stroking parameters during sprint competition to gain insight into the race management of speed (S), stroke length (SL), stroke rate (SR) and stroke index (SI) in relation to gender. The stroking parameters of 32 male and 32 female finalists in the 2015 World Championships and French Championships were analysed during 50-m and 100-m freestyle events. Using a video-derived two-dimensional direct linear transformation system, the biological coefficients of variation (BCV) between cycles were computed for the 50-m and the two laps of the 100-m (L1100, L2100). Speed changes within each lap were modelled by linear, quadratic or cubic models. The 50-m showed higher S and SR but lower SL and SI than L1100. The 50-m exhibited greater BCV S than L1100, which showed higher S, SR, SL and SI than L2100. BCV S and BCV SL were lower in L1100 than L2100 but BCV SR was higher in L1100 than L2100. Male swimmers showed greater BCV S than female swimmers in the 50-m and L1100. For the whole population, the linear regression model was dominant in the 50-m (53.1%), L1100 (53.1%) and L2100 (43.8%). High mean speed often related to high intra-lap speed fluctuations and a linear speed decrease in the 50-m suggesting an ‘all-out’ pacing, while lower fluctuations occurred during the 100-m suggesting an ‘economical’ pacing.

Training methods and analysis of races of a top level Paralympic swimming athlete

Training methods for Paralympic swimmers must take into account different pathologies, competitions classes, athlete’s individual circumstances and peculiar physical adaptation mechanisms, hence general guidelines cannot be found in literature. In this study we present a training program, implemented for the physical preparation of a top level Paralympic swimmer. The athlete under study, affected by infantile cerebral palsy within a clinical picture of a spastic tetraparesis, by the end of 2016 was holder of Italian, European, world and Paralympic titles in the 400-m freestyle competition, S6 class. The training macrocycle was structured in a 3-fold periodization (three mesocycles), in view of the preparation to three international competitions. The 4-month training mesocycles prior to each competition differed substantially in terms of mileage load, intensity and recovery times. The first mesocycle was characterized by a sizeable low-intensity mileage load, the second one was shifted to lower mileage load, carried out at middle-to-high intensity levels, the third one entailed increased effort intensity, counterbalanced by lower mileage load. In all cases, recovery times were balanced to obtain optimized performance through physical adaptation to training stimuli, keeping into account the physiopatological response. Tapering phases were adjusted to maximize performance at competition. As an assessment of the effectiveness of the training method, correspondence between chronometric and technical parameters in the three competitions and the respective mesocycle training programs was found. The results of the present study may support the development of training guidelines for athletes affected by upper motor neuron lesions.

A novel method to guide classification of para swimmers with limb deficiency.

The International Paralympic Committee has directed International Federations that govern Para sports to develop evidence-based classification systems. This study defined the impact of limb deficiency impairment on 100m freestyle performance to guide an evidence-based classification system in Para Swimming, which will be implemented following the 2020 Tokyo Paralympic games. Impairment data and competitive race performances of 90 international swimmers with limb deficiency were collected. Ensemble partial least squares regression established the relationship between relative limb length measures and competitive 100m freestyle performance. The model explained 80% of the variance in 100m freestyle performance and found hand length and forearm length to be the most important predictors of performance. Based on the results of this model, Para swimmers were clustered into four-, five-, six-, and seven-class structures using nonparametric kernel density estimations. The validity of these classification structures, and effectiveness against the current classification system, were examined by establishing within-class variations in 100m freestyle performance and differences between adjacent classes. The derived classification structures were found to be more effective than current classification based on these criteria. This study provides a novel method that can be used to improve the objectivity and transparency of decision-making in Para sport classification. Expert consensus from experienced coaches, Para swimmers, classifiers, and sport science and medicine personnel will benefit the translation of these findings into a revised classification system that is accepted by the Para swimming community.

Relationship Between Dryland Strength and Swimming Performance: Pull-Up Mechanics as a Predictor of Swimming Speed.

Pérez-Olea, JI, Valenzuela, PL, Aponte, C, and Izquierdo, M. Relationship between dryland strength and swimming performance: pull-up mechanics as a predictor of swimming speed. J Strength Cond Res 32(6): 1637-1642, 2018-This study aimed to examine the validity of the countermovement jump (CMJ) and the pull-up exercise as predictors of swimming performance. Twelve young male swimmers (Mean ± SD, 19 ± 3 years; 75 ± 10 kg; 180 ± 6 cm) with a homogenous level of performance (50-m freestyle time [50F]: 26.41 ± 1.44 seconds, coefficient of variance: 5.5%) participated in this study. Subjects performed a test of a single pull-up (PU) and a test of maximum number of pull-ups until muscular failure (PUF), and the mechanics of the ascending phase were recorded using a lineal force transducer. The height reached in a single CMJ test and the mean height during 30 consecutive CMJs were also determined. The swimmers' 50-m leg-only swimming time (50L) was also registered. The 50F time was strongly correlated with different variables of the PU (r = -0.76 to -0.80; p ≤ 0.05) and PUF test (r = -0.64 to -0.88; p ≤ 0.05), but not with the number of pull-ups performed. A significant relationship between 50F and 50L was observed (r = 0.78; p ≤ 0.05), with no relationship between the CMJ tests and swimming performance. Furthermore, multiple linear regression showed that 50L and the relative loss of velocity during the PUF test accounted for 84% (p < 0.001) of the 50F performance variance. This study shows the validity of the analysis of pull-up mechanics and 50L to predict short-distance swimming performance in trained swimmers, confirming the importance of upper-limb strength and leg kick on this sport.

Training Program for Military Students for the Improvement of the Freestyle Swimming Method

Abstract In this paper we wanted to demonstrate that improving swimming performance, even over a short period of time, requires a centralized training program. The subjects of the research were checked on a distance of 50m freestyle before and after the application of the centralized training program, and the results were compared with those from the control group who did not benefit from the centralized training program, the latter ones having participated only in the classes of the approved syllabus. All the results from the research were interpreted objectively, the resulting figures being the actual support of this study. The tests and the program applied proved relevant in view of the purpose of this study

The transfer of strength and power into the stroke biomechanics of young swimmers over a 34-week period

The purpose of this study was to learn the interplay between dry-land strength and conditioning, and stroke biomechanics in young swimmers, during a 34-week training programme. Twenty-seven swimmers (overall: 13.33 ± 0.85 years old; 11 boys: 13.5 ± 0.75 years old; 16 girls: 13.2 ± 0.92 years old) competing at regional- and national-level competitions were evaluated. The swimmers were submitted to a specific in-water and dry-land strength training over 34 weeks (and evaluated at three time points: pre-, mid-, and post-test; M1, M2, and M3, respectively). The 100-m freestyle performance was chosen as the main outcome (i.e. dependent variable). The arm span (AS; anthropometrics), throwing velocity (TV; strength), stroke length (SL), and stroke frequency (SF; kinematics) were selected as independent variables. There was a performance enhancement over time (M1 vs. M3: 68.72 ± 5.57 s, 66.23 ± 5.23 s; Δ = −3.77%; 95% CI: −3.98;−3.56) and an overall improvement of the remaining variables. At M1 and M2, all links between variables presented significant effects (p < .001), except the TV–SL and the TV–SF path. At M3, all links between variables presented significant effects (p ≤ .05). Between M1 and M3, the direct effect of the TV to the stroke biomechanics parameters (SL and SF) increased. The model predicted 89%, 88%, and 92% of the performance at M1, M2, and M3, respectively, with a reasonable adjustment (i.e. goodness-of-fit M1: χ2/df = 3.82; M2: χ2/df = 3.08; M3: χ2/df = 4.94). These findings show that strength and conditioning parameters have a direct effect on the stroke biomechanics, and the latter one on the swimming performance.

Dynamics of the Metabolic Response During a Competitive 100-m Freestyle in Elite Male Swimmers.

To compare the dynamics of maximal oxygen uptake ([Formula: see text]), blood lactate ([La]b), total energy expenditure (Etot), and contributions of the aerobic (Eaer), alactic anaerobic (Ean,al), and lactic anaerobic (Ean,lac) metabolic energy pathways over 4 consecutive 25-m laps (L0-25, L25-50, etc) of a 100-m maximal freestyle swim. Elite swimmers comprising 26 juniors (age = 16 [1]y) and 23 seniors (age = 24 [5]y) performed 100m at maximal speed and then 3 trials (25, 50, and 75m) at the same pace as that of the 100m. [La]b was collected, and [Formula: see text] was measured 20 s postexercise. The estimated energetic contributions for the 100-m trial are presented as mean (SD): Eaer, 51% (8%); Ean,al, 18% (2%); Ean,lac, 31% (9%). [Formula: see text] increased from L0-25 to L25-50 (mean = 3.5L·min-1; 90% confidence interval [CI], 3.4-3.7L·min-1 to mean = 4.2L·min-1; 90% CI, 4.0-4.3L·min-1) and then stabilized in the 2nd 50m (mean = 4.1L·min-1; 90% CI, 3.9-4.3L·min-1 to mean = 4.2L·min-1; 90% CI, 4.0-4.4L·min-1). Etot (juniors, 138 [18]kJ; seniors, 168 [26]kJ), Ean,al (juniors, 27 [3]kJ; seniors, 30 [3]kJ), and Ean,lac (juniors, 38 [12]kJ; seniors, 62 [24]kJ) were 11-58% higher in seniors. Faster swimmers (n = 26) had higher [Formula: see text], 90% CI 4.4-4.8L·min-1 [Formula: see text] L·min-1, 90% CI 3.6-4.2L·min-1), and Eaer power was associated with fast performances (P < .001). Faster swimmers were characterized by higher [Formula: see text] and less time to reach the highest [Formula: see text] at ∼50m of the 100-m swim. Anaerobic qualities become more important with age.

The effects of concurrent visual feedback on the control of swimming intensities above the onset of blood lactate accumulation

PurposeEffective control of swimming speed can increase training effectiveness and therefore enhance training adaptations. The aim of the present study was to investigate the effects of concurrent visual feedback on swimming speed at an exercise intensity above the onset of blood lactate accumulation (OBLA).MethodsThe study involved 12 healthy male and female swim team members. The participants executed two 200-m freestyle trials within an individually predetermined swim time matching an exercise intensity above OBLA (exercise zone 4). In one trial, no additional information was provided, whereas concurrent visual feedback was given on swimming speed in the other.ResultsConcurrent visual feedback narrowed the discrepancy between the predetermined and obtained swimming times (&lt;i&gt;p&lt;/i&gt; &lt; 0.001). This improvement in swimming time (accuracy) showed a negative correlation with the increase in post-trial lactate concentration. The correlation between the difference in the predetermined and obtained times and the increase in lactate was &lt;i&gt;R&lt;/i&gt; = –0.46 when no visual feedback was provided but &lt;i&gt;R&lt;/i&gt; = –0.64 with visual feedback, with the latter result statistically significant (&lt;i&gt;p&lt;/i&gt; = 0.024).ConclusionsConcurrent visual feedback allows swimmers to consistently maintain a predetermined swimming speed and therefore keep the specified exercise intensity as evidenced by the increase in lactate concentration. This can result in more effective execution of training goals and thereby enhance training outcomes.

The effects of 12-weeks thera-band training on swimming performance at 11-13 age group swimmers &lt;p&gt;11-13 yaş grubu erkek yüzme sporcularında 12 haftalık terabant antrenmanının yüzme performansına etkileri

Elastic tapes are one of the functional equipments used for strength development. The purpose of this study was to determine the effects of resistance band trainings on swimming performance in 11-13 year old male swimming athletes. The swimmer who regularly swim for at least two years were at random divided 2 groups. Group1, swimming+thera-band (STG) (n=12, age= 12,00±0,60 years, height=147,75±8,12 cm, body weight=41,91±9,26 kg) participated 2 days swimming and swimming training plus 3 days resistance with theraband during 12 weeks while Group 2, swimming group (SG), (n=12, age=11,91±0,79 years, height=148,25±9,25cm body weight =43,50±9,05 kg) continued just 5 days swimming training per week. To evaluate the swimming performances of the groups, 50m, 100m, 150m and 200m freestyle transition tests with 25m, 50m freestyle swimming were measured before and after training. Wilcoxon paired test and Mann-Whitney U test were performed using the SPSS 15.0 statistical program in the analysis of the obtained data. At the end of the interview, significant decrease were found in both groups of 25m, 50m freestyle swimming grades and 200m grades (p&lt;0,05). As a result of the findings, it can be said that therabant training which is done as a land work with swimming training leads to positive changes in the performance development of children aged 11-13 years.Extended English abstract is in the end of Full Text PDF (TURKISH) file.ÖzetElastik bantlar kuvvet gelişimi için kullanılan fonksiyonel ekipmanlardan biridir. Bu araştırma, yaşları 11-13 arasında olan erkek yüzme sporcularında direnç bandı antrenmanının yüzme performansına etkilerini belirlemek amacıyla yapılmıştır. Düzenli olarak en az iki yıl yüzme antrenmanı yapan erkek yüzücüler rastgele iki gruba ayrılmıştır. 1. Grup yüzme+thera-band (YTG) (n=12, yaş=12,00±0,60 yıl, boy=147,75±8,12 cm, v.ağ=41,91±9,26 kg) 12 hafta boyunca haftada 2 gün yüzme, 3 gün de yüzmeye ek olarak therabant ile kuvvet antrenmanı 2. Grup yüzme (YG) (n=12, yaş=11,91±0,79 yıl, boy=148,25±9,25cm v.ağ=43,50±9,05 kg) haftada 5 gün sadece yüzme antrenmanları uygulanmıştır. Grupların yüzme performanslarını değerlendirmek için 25m, 50m serbest stil yüzme ile 50m, 100m, 150m ve 200m serbest stil geçiş testleri antrenman öncesi ve sonrası ölçülmüştür. Bulgular SPSS 15.0 istatistik paket programında analiz edilmiş ve parametrik olmayan analizlerden Mann Whitney U testi ile Wilcoxon İkili İlişki testi uygulanmıştır. Araştırmanın sonunda her iki grubunda 25m, 50m serbest stil yüzme dereceleri ile 200m yüzme derecelerinde anlamlı azalmalar bulunmuştur (p&lt;0,05). Elde edilen bulgular neticesinde, yüzme antrenmanları ile birlikte kara çalışması olarak yaptırılan therabant antrenmanlarının 11-13 yaşları arasındaki çocukların performans gelişimlerinde olumlu değişimlere neden olduğu söylenebilir.Elastic tapes are one of the functional equipments used for strength development. The purpose of this study was to determine the effects of resistance band trainings on swimming performance in 11-13 year old male swimming athletes. The swimmer who regularly swim for at least two years were at random divided 2 groups. Group1, swimming+thera-band (STG) (n=12, age= 12,00±0,60 years, height=147,75±8,12 cm, body weight=41,91±9,26 kg) participated 2 days swimming and swimming training plus 3 days resistance with theraband during 12 weeks while Group 2, swimming group (SG), (n=12, age=11,91±0,79 years, height=148,25±9,25cm body weight =43,50±9,05 kg) continued just 5 days swimming training per week. To evaluate the swimming performances of the groups, 50m, 100m, 150m and 200m freestyle transition tests with 25m, 50m freestyle swimming were measured before and after training. Wilcoxon paired test and Mann-Whitney U test were performed using the SPSS 15.0 statistical program in the analysis of the obtained data. At the end of the interview, significant decrease were found in both groups of 25m, 50m freestyle swimming grades and 200m grades (p&lt;0,05). As a result of the findings, it can be said that therabant training which is done as a land work with swimming training leads to positive changes in the performance development of children aged 11-13 years.

Adaptive thermogenesis and changes in body composition and physical fitness in army cadets.

To analyze the association between a 34-week military training on body composition, physical fitness and compensatory changes in resting energy expenditure (REE) recognized as adaptive thermogenesis (AT). We also explored if regional body composition changes were related to AT. Twenty-nine male army cadets, aged 17 to 22 years were tested at baseline (T0) and after 34-weeks military training (T1). Physical training was performed 5 days/week during 90 minutes/day. Measurements included body composition by dual-energy x-ray absorptiometry; physical fitness by 3000-m running, pull-up, 50-m freestyle swimming, push-up and sit-up tests; REE measured by indirect calorimetry (REEm) and predicted from fat-free mass (FFM), fat mass (FM) and ethnicity at T0 (REEp). %AT was calculated using values at T1: 100(REEm/REEp-1); and AT (kcal/day) as %AT/100 multiplied by baseline REEm. Physical training was associated with increases of lean soft tissue (LST) (∆1.2±1.3 kg), FM (∆1.4±1.3 kg), FFM (∆1.2±1.3 kg) and physical fitness (P<0.01), but no REE changes (∆59.6±168.9 kcal/day) and AT were observed (P>0.05). Though a large variability was found, AT was partially explained by trunk LST (r2=0.17, P=0.027). Individuals showing a higher AT response demonstrated a higher trunk LST increase (∆0.8±0.7 kg, P<0.05). The military training increased LST, FM, FFM and physical fitness. Though no mean changes in AT occurred, a large individual variability was observed with some participants increasing REE beyond the expected body composition changes, suggesting a spendthrift phenotype. Changes of trunk LST may play an important role in the AT response observed in these individuals.

Functional Role of Movement and Performance Variability: Adaptation of Front Crawl Swimmers to Competitive Swimming Constraints.

To study the variability in stroking parameters between and within laps and individuals during competitions, we compared and modeled the changes of speed, stroke rate, and stroke length in 32 top-level male and female swimmers over 4 laps (L1-L4) in 200-m freestyle events using video-derived 2-dimensional direct linear transformation. For the whole group, speed was greater in L1, with significant decreases across L2, L3, and L4 (1.80 ± 0.10 vs 1.73 ± 0.08; 1.69 ± 0.09; 1.66 ± 0.09 · s-1, P < .05). This variability was attributed to a decrease in stroke length (L2: 2.43 ± 0.19 vs L4: 2.20 ± 0.13m, P < .05) and an increase in stroke rate (L2: 42.8 ± 2.6 vs L4: 45.4 ± 2.3 stroke · min-1, P < .05). The coefficient of variation and the biological coefficient of variation in speed were greater for male versus female (3.9 ± 0.7 vs 3.1 ± 0.7; 2.9 ± 1.0 vs 2.6 ± 0.7, P < .05) and higher in L1 versus L2 (3.9 ± 1.3 vs 3.1 ± 0.1; 2.9 ± 0.9 vs 2.3 ± 0.7, P < .05). Intra-lap speed values were best represented by a cubic (n = 38), then linear (n = 37) and quadratic model (n = 8). The cubic fit was more frequent for males (43.8%) than females (15.6%), suggesting greater capacity to generate higher acceleration after the turn. The various stroking parameters managements within lap suggest that each swimmer adapts his/her behavior to the race constraints.

In-Water Resisted Swim Training for Age-Group Swimmers: An Evaluation of Training Effects.

The purpose of this study is to compare the efficacy of resisted sprint swim training with that of nonresisted sprint swim training on 50-m freestyle competition time (Vmax50) in age-group swimmers. Twenty-four age-group swimmers (age 10.6-14.9 y) were divided into resisted or nonresisted sprint swim training groups and completed a sprint swim training intervention 2 times per week for 10 weeks. Repeated 10-m sprints with progressively increasing resistance were used to determine measures of swim power. Skeletal muscle mass was estimated using B-mode ultrasound. Maturity status was estimated using predicted adult height (%Htadult) and maturity offset. A 2-way repeated-measures analysis of variance revealed no group × time interaction for measured variables. Vmax50 was correlated with skeletal muscle mass and swim power variables, but no significant relationship was found between relative changes in these variables. Estimated maturity status (%Htadult) appeared to be associated with initial measures of swim power and performance variables. Ten weeks of resisted sprint swim training was not any more effective than nonresisted sprint swim training at improving sprint swim performance in age-group swimmers.

Swim Speed Tests as a Method for Differentiating the Profiles of Young Swimmers

Swimming tests are used in every training cycle and seasons with purpose of estimating swimming performance and evaluate certain training types. The focus of this study is an attempt to distinguish between the potential short-distance and longer-distance swimmers, as well as the swimmers who could have desirable profiles for particular swimming styles. For this purpose, several aims are given: () to determine the latent dimensions of the performances in swimming tests, conducted on various distances and performed using different swimming styles ; 2) to determine the correlations between speeds on various distances using different swimming styles ; 3) to determine the differences in various distance speeds at the same swimmers ; 4) to determine the profiles of swimmers, based on the various distance speeds (4). Male swimmers (N=68), aged 14 to 16 from five Zagreb clubs were tested. Four swimming tests were used to measure speed (25-m freestyle, backstroke, breaststroke, butterfly), five swimming tests measured speed endurance (50-m freestyle, 100-m freestyle, backstroke, breaststroke, butterfly), while only one test measured endurance (800-m freestyle). The results revealed two interpretable and highly reliable latent dimensions of swimming tests. Factor analysis of the scores in swimming tests differentiated the variables of swimming tests that describe breaststrokes and other strokes. Most of the scores in the swimming tests are positively correlated (in range 0.25-0.85), while no differences in various distance speeds among the same swimmers are found. The results indicate the importance of using swimming tests, especially in breaststrokes styles, because of their specific motor structure.

Warm-up for Sprint Swimming: Race-Pace or Aerobic Stimulation? A Randomized Study.

Neiva, HP, Marques, MC, Barbosa, TM, Izquierdo, M, Viana, JL, Teixeira, AM, and Marinho, DA. Warm-up for sprint swimming: race-pace or aerobic stimulation? A randomized study. J Strength Cond Res 31(9): 2423-2431, 2017-The aim of this study was to compare the effects of 2 different warm-up intensities on 100-m swimming performance in a randomized controlled trial. Thirteen competitive swimmers performed two 100-m freestyle time-trials on separate days after either control or experimental warm-up in a randomized design. The control warm-up included a typical race-pace set (4 × 25 m), whereas the experimental warm-up included an aerobic set (8 × 50 m at 98-102% of critical velocity). Cortisol, testosterone, blood lactate ([La]), oxygen uptake (V[Combining Dot Above]O2), heart rate, core (Tcore and Tcorenet) and tympanic temperatures, and rating of perceived exertion (RPE) were monitored. Stroke length (SL), stroke frequency (SF), stroke index (SI), and propelling efficiency (ηp) were assessed for each 50-m lap. We found that V[Combining Dot Above]O2, heart rate, and Tcorenet were higher after experimental warm-up (d > 0.73), but only the positive effect for Tcorenet was maintained until the trial. Performance was not different between conditions (d = 0.07). Experimental warm-up was found to slow SF (mean change ±90% CL = 2.06 ± 1.48%) and increase SL (1.65 ± 1.40%) and ηp (1.87 ± 1.33%) in the first lap. After the time-trials, this warm-up had a positive effect on Tcorenet (d = 0.69) and a negative effect on [La] (d = 0.56). Although the warm-ups had similar outcomes in the 100-m freestyle, performance was achieved through different biomechanical strategies. Stroke length and efficiency were higher in the first lap after the experimental warm-up, whereas SF was higher after control warm-up. Physiological adaptations were observed mainly through an increased Tcore after experimental warm-up. In this condition, the lower [La] after the trial suggests lower dependency on anaerobic metabolism.

Observación automatizada: la variabilidad de la frecuencia cardíaca y su relación con las variables psicológicas determinantes del rendimiento en nadadores jóvenes

&lt;p style="margin: 0cm 0cm 0pt; line-height: 150%;"&gt;&lt;span style="font-size: medium;"&gt;&lt;span style="font-family: 'Times New Roman',serif; mso-ansi-language: EN-US;" lang="EN-US"&gt;Correct interpretation of performance markers from&lt;/span&gt;&lt;span style="font-family: 'Times New Roman',serif; mso-ansi-language: EN-US; mso-ascii-theme-font: minor-bidi; mso-hansi-theme-font: minor-bidi; mso-bidi-font-family: 'Times New Roman'; mso-bidi-theme-font: minor-bidi;" lang="EN-US"&gt; a psychophysiological perspective is important in young developing athletes. This study had two objectives. The first was to analyze the relationship between heart rate variability (HRV) and the psychological variables sleep quality, self-esteem, and mood states in young swimmers from a professional swimming club. The second was to study the relationship between performance and HRV and psychological determinants. The sample was composed of nine swimmers (11.7&lt;span style="color: #1c1c1c;"&gt;±1.4 years) base on purposive sampling method. Data were collected once a week during training sessions for 3 weeks. The statistical analysis showed that anxiety was negatively correlated with the high frequency component of HRV (Ln HF) and positively correlated with the very low frequency component (Ln LVF). No significant correlations were observed for self-esteem or sleep quality. Performance in a 200-m freestyle event was negatively correlated with the parasympathetic HRV indices. Our results suggest that HRV could be a valid tool for predicting performance and improving interpretation of psychometric tests. &lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;/p&gt;

Classificação esportiva para atletas com deficiência visual e sua relação com o desempenho na natação

The medical classification (MC) adopted for swimmers with vision visual impairment (VI) does not clearly elucidate the influence of vision loss on performance. In a documentary research, the final time in the 50-, 100- and 400-m freestyle events and MC (S11, S12 and S13) of national (n = 40) and international (n = 72) elite swimmers was analyzed. The analysis was performed using the Kruskal-Wallis test and Spearman’s correlation with 95% confidence (P < 0.05) and Cohen’s d was calculated. There was a large effect of MC on the final time in the 50-m (P = 0.034, d = 1.55) for national athletes and in the 50-m (P = 0.001, d = 2.64), 100-m (P = 0.001, d = 3.01) and 400-m (P = 0.001, d = 2.88) for international athletes. S12 and S13 classes were faster compared to S11 class for all international events, but only in the 50-m for the national event (P < 0.05). It was found a strong negative relationship between the final time and MC for international athletes (Spearman’s Rho ≥ 0.78). There was a significant influence of MC on the performance of swimmers in freestyle races, especially in international swimmers. Thus, having a visual residue seems to be sufficient for S12 and S13 swimmers to achieve similar performance.

Classificação esportiva para atletas com deficiência visual e sua relação com o desempenho na natação

DOI: http://dx.doi.org/10.5007/1980-0037.2017v19n2p196 The medical classification (MC) adopted for swimmers with vision visual impairment (VI) does not clearly elucidate the influence of vision loss on performance. In a documentary research, the final time in the 50-, 100- and 400-m freestyle events and MC (S11, S12 and S13) of national (n = 40) and international (n = 72) elite swimmers was analyzed. The analysis was performed using the Kruskal-Wallis test and Spearman’s correlation with 95% confidence (P &lt; 0.05) and Cohen’s d was calculated. There was a large effect of MC on the final time in the 50-m (P = 0.034, d = 1.55) for national athletes and in the 50-m (P = 0.001, d = 2.64), 100-m (P = 0.001, d = 3.01) and 400-m (P = 0.001, d = 2.88) for international athletes. S12 and S13 classes were faster compared to S11 class for all international events, but only in the 50-m for the national event (P &lt; 0.05). It was found a strong negative relationship between the final time and MC for international athletes (Spearman’s Rho ≥ 0.78). There was a significant influence of MC on the performance of swimmers in freestyle races, especially in international swimmers. Thus, having a visual residue seems to be sufficient for S12 and S13 swimmers to achieve similar performance.

Confirming the Value of Swimming-Performance Models for Adolescents.

To evaluate the efficacy of existing performance models to assess the progression of male and female adolescent swimmers through a quantitative and qualitative mixed-methods approach. Fourteen published models were tested using retrospective data from an independent sample of Dutch junior national-level swimmers from when they were 12-18 y of age (n = 13). The degree of association by Pearson correlations was compared between the calculated differences from the models and quadratic functions derived from the Dutch junior national qualifying times. Swimmers were grouped based on their differences from the models and compared with their swimming histories that were extracted from questionnaires and follow-up interviews. Correlations of the deviations from both the models and quadratic functions derived from the Dutch qualifying times were all significant except for the 100-m breaststroke and butterfly and the 200-m freestyle for females (P < .05). In addition, the 100-m freestyle and backstroke for males and 200-m freestyle for males and females were almost directly proportional. In general, deviations from the models were accounted for by the swimmers' training histories. Higher levels of retrospective motivation appeared to be synonymous with higher-level career performance. This mixed-methods approach helped confirm the validity of the models that were found to be applicable to adolescent swimmers at all levels, allowing coaches to track performance and set goals. The value of the models in being able to account for the expected performance gains during adolescence enables quantification of peripheral factors that could affect performance.