Improvements In Swimming Performance Research Articles

Gender-related differences in kinematic parameters of the start and performance in a 50m breaststroke swimming

Introduction: In swimming, the competitions are divided by age categories, with each swimming event beginning at the start. For optimal improvements in swimming performance in the sprint events, the performance at the start and during swimming in each age category should be analyzed. Aim: The aim of our study is to show the differences in kinematic parameters of the start and performance in the sprint event of 50 m breaststroke from the perspective of gender in different age groups at international competitions organized in Slovakia. Materials and Methods: The females were categorized by age into K3 (2010-2011; n=36; 282 WA points), K2 (2008-2009; n=26; 409 WA points) and K1 (2007 and older; n=34; 503 WA points) groups. Males were categorized into K3 (2009-2010; n=27; 265 WA points), K2 (2007-2008; n=33; 372 WA points) and K1 (2006 and older; n=39; 207 WA points) groups. We used SwimPro cameras and Dartgish software to monitor kinematic parameters in the above-water, underwater, and swim phases. The parameters monitored were block time (BT), time (FT), and length (FD) of flight, time (UWT) and length (UWD) underwater, swim time (ST) and distance (SD) to 15 m, time to 15 m (T15), 25 m (T25), and 50 m (T50) distance. Data were tested by Shapiro-Wilk, Kruskal-Wallis ANOVA, and Mann-Whitney U test in Statistica software (version 13.5). Results: Statistically significant differences (p<0.01) in females were found in the above-water phase in BT, FT, and FD between K3 and K1. The underwater phase in UWT showed differences between K3 to K1, K2 to K1 whereas for UWD - between K3 and K2 and between K2 and K1. For T15 and T25, there were differences (p<0.01) between all categories, but in the final time (T50), the differences occurred between K3 and K2 and between K3 and K1. In males, there was a significant difference in the above-water phase between K3 and K1 and between K2 and K1. In UWD, ST, SD, T15, T25, and T50, there were significant differences between all categories. Differences (p>0.01) between males and females by category in the above-water phase were measured in FT (K1) and FD (K2, K1). In the underwater phase, the differences were found in UWT (K2) and UWD (K1). For T15, T25, and T50, significant differences were shown in all categories. Conclusions: The kinematic analysis revealed differences not only in the start phases and the 50 m breaststroke swimming in the male and female categories but also between genders. Differences in swimming performance may be due to performance at the start and therefore more attention should be paid to the start phases in the different categories of swimmers.

The effects of inspiratory muscle training on swimming performance: A study on the cohort of swimming specialization students

PurposeCurrent evidence posits a strong correlation between respiratory muscle function and swimming performance. Despite this, few studies have explored the integration of inspiratory muscle training (IMT) into standard swimming training regimens, which remains an unexplored avenue for improving performance in swimmers. This study aims to evaluate the potential advantages of IMT for enhancing respiratory function and swimming performance and determine whether such training could induce beneficial physiological adaptations. MethodsWe designed and conducted a randomized controlled trial involving 43 swimming specialization students aged 18–25 years. Participants were randomly allocated to two groups: a control group, which followed regular swimming training, and an experimental group, which complemented the standard training with IMT. The intervention lasted for six weeks. Key outcomes measured included swimming performance metrics (time of 50 m freestyle, number of breaths in 50 m freestyle, distance before first breath in freestyle, time of 100 m freestyle) and various inspiratory muscle function parameters such as vital capacity (VC), maximum inspiratory pressure (MIP), maximum inspiratory flow (MIF), and maximum inspiratory capacity (MIC). We also assessed certain biochemical parameters, including hemoglobin, creatine kinase (CK), blood urea nitrogen (BUN), testosterone, and cortisol concentrations. ResultsFollowing the training period, the experimental group exhibited significant improvements in swimming performance and respiratory function parameters. We also noted an increase in hemoglobin levels and a reduction in testosterone concentrations in this group, suggesting beneficial physiological adaptations in response to the combined IMT and swimming training. ConclusionOur findings underline the potential of IMT as a supplementary training modality for enhancing respiratory function and improving swimming performance. The changes in biochemical parameters suggest physiological adaptations that might contribute to these observed improvements. This study opens the door for future research on the benefits of integrating IMT into training regimens for competitive swimmers. Further investigation is warranted to fully elucidate the mechanisms behind the observed benefits and to validate these findings in a larger cohort and other athlete populations.

Anthropometric and Physical Performance Characteristics of Swimmers

Introduction: The study of body measurements and proportions by anthropometry is important for the identification of young talents in swimming. Therefore, the aim of this study was to a) compare the physical performance profile of swimmers on land and in water and b) understand the relationship between anthropometric and physical performance tests. Methods: To this end, 31 anthropometric variables were determined in 6 male (n=3) and female (n=3) swimmers using the International Society for the Advancement of Kinanthropometry (ISAK) protocols and VO2max laboratory tests. Body fractionation (adipose, muscle, bone, residual, and skin tissue masses) was determined using the validated Kerr & Ross five-way fractionation model for body composition. Data analysis included the person correlation coefficient. Results: The swimming performance test was positively strongly correlated with body height, seat height, arm span, shoulder and pelvic width, and arm and leg length (p ≤ 0.001). In conclusion, these studies reveal some potential key anthropometric factors in the performance of active swimmers. These results support the view that while swimmers have unique anthropometric profiles, more successful swimmers tend to have greater arm spans. Conclusion: These results suggest that anthropometric characteristics are important in swimming performance. This study concluded that improvement in swimming performance is strongly related to anthropometric and kinanthropometric profiles.

Swimming performance, physiology, and post-activation performance enhancement following dryland transition phase warmup: A systematic review.

BackgroundIn swimming, the period between the end of the swimming warmup and the beginning of competition is critical to performance, here termed the transition phase. Several options are available during this phase, necessitating a systematic review to understand if optimal strategies exist.ObjectivesTo synthesise and critically evaluate the current literature investigating land-based warmup interventions on subsequent performance in competitive swimmers.MethodsA search of three electronic databases (PubMed, EBSCO SPORTDiscus and Web of Science) was conducted to identify original studies until February 2022. Selection criteria dictated that (i) a control condition was used, (ii) participants were ≥ 15 years of age, (iii) a pool-based warmup was done prior to the land-based warmup. A total of 25 articles met the selection criteria.ResultsReducing the transition phase duration by at least half led to consistently faster time-trial times of between 1.1–1.5% for all included studies. Passive warmups using clothing interventions resulted in mostly faster time-trial’s of 0.4–0.8% with increases in skin temperature frequent, though little change occurred in core temperature. The methodology of passive respiratory warmups were vastly different with positive time-trial’s effects ranging between 0.9–1.1% for two studies, though one reported no meaningful difference. Active warmups led to consistently faster time-trial’s between 0.7–0.9%, though the unpinning factors are not clear. Warmups which combined passive and active options frequently led to faster time-trial’s between 0.8–3%. Upper and combined limb post-activation performance enhancement led to mostly unfavourable time-trial changes. Lower limb exclusive protocols results were inconsistent, with limited beneficial effects on time-trial or start performance reported following plyometric protocols. However, there does appear merit in heavier loaded lower limb protocols.ConclusionEach of a reduced transition phase length, and passive, active or combination warmup have demonstrated improvements in swimming performance. Conversely, PAPE protocols should be used with caution, especially when including the upper limbs.

Wetsuit Use During Open Water Swimming. Does It "Suit" Everybody? A Narrative Review.

Although wearing a wetsuit while swimming, when permitted, is primarily for safety reasons (ie,to protect against hypothermia), changes in buoyancy, biomechanics, and exercise performance have been reported. This narrative review covers the benefits of different wetsuit models on performance in swimming and triathlon. A computer search of online databases was conducted to locate relevant published research until March 2021. After the screening process, 17 studies were selected for analysis. Most of the selected studies involved pool swimmers or triathletes completing short or middle distances in a pool while using a full or a long sleeveless wetsuit. Swimming with wetsuit elicited significant improvements in performance (maximum 11%), mainly by decreasing drag and energy cost, by increasing buoyancy, and by affecting technique. Different rates of change in each factor were found according to swimming ability and wetsuit model. In addition, wearing a wetsuit was often rated as uncomfortable by athletes. Although improvement in swimming performance by wearing a wetsuit has been reported in the literature, the amplitude of the improvement remains questionable. The enhancement in swimming performance is attributable merely to improvements in propulsion proficiency and buoyancy, as well as a reduction in drag. The extent to which athletes are familiar with the use of a wetsuit, their swimming ability, and the wetsuit model may play important roles in this improvement. More studies simulating competition and comparing elite versus nonelite athletes are needed.

Targeting the Mild-Hypoxia Driving Force for Metabolic and Muscle Transcriptional Reprogramming of Gilthead Sea Bream (Sparus aurata) Juveniles.

Simple SummaryReduced oxygen availability generates a number of adaptive features across all the animal kingdom, and the goal of this study was targeting the mild-hypoxia driving force for metabolic and muscle transcriptional reprogramming of gilthead sea bream juveniles. Attention was focused on blood metabolic and muscle transcriptomic landmarks before and after exhaustive exercise. Our results after mild-hypoxia conditioning highlighted an increased contribution of lipid metabolism to whole energy supply to preserve the aerobic energy production, a better swimming performance regardless of changes in feed intake, as well as reduced protein turnover and improved anaerobic fitness with the restoration of normoxia.On-growing juveniles of gilthead sea bream were acclimated for 45 days to mild-hypoxia (M-HYP, 40–60% O2 saturation), whereas normoxic fish (85–90% O2 saturation) constituted two different groups, depending on if they were fed to visual satiety (control fish) or pair-fed to M-HYP fish. Following the hypoxia conditioning period, all fish were maintained in normoxia and continued to be fed until visual satiation for 3 weeks. The time course of hypoxia-induced changes was assessed by changes in blood metabolic landmarks and muscle transcriptomics before and after exhaustive exercise in a swim tunnel respirometer. In M-HYP fish, our results highlighted a higher contribution of aerobic metabolism to whole energy supply, shifting towards a higher anaerobic fitness following normoxia restoration. Despite these changes in substrate preference, M-HYP fish shared a persistent improvement in swimming performance with a higher critical speed at exercise exhaustion. The machinery of muscle contraction and protein synthesis and breakdown was also largely altered by mild-hypoxia conditioning, contributing this metabolic re-adjustment to the positive regulation of locomotion and to the catch-up growth response during the normoxia recovery period. Altogether, these results reinforce the presence of large phenotypic plasticity in gilthead sea bream, and highlights mild-hypoxia as a promising prophylactic measure to prepare these fish for predictable stressful events.

EFFECTS OF INDIVIDUALIZED TRAINING AND RESPIRATORY MUSCLE TRAINING IN IMPROVING SWIMMING PERFORMANCE AMONG COLLEGIATE SWIMMERS - AN EXPERIMENTAL STUDY

Previous researches have been conducted to determine the types of training to improve swimming performance. Nevertheless, no study has been done on the individualized training approach among swimmers. Hence, this study aimed (i) to examine the effects of respiratory muscle training on swimming performance (ii) to examine the effects of combined respiratory muscle training with individualized training on swimming performance, and (iii) to compare the differences between the isolated respiratory muscle training, combined intervention of respiratory muscle training with individualized training and usual training on swimming performance. For this, 45 collegiate swimmers with no previous injuries and swims regularly for at least 1 hour per week participated in the study. Participants were randomly assigned into three groups; Group A: Respiratory muscle training and Individualized Training, Group B: Respiratory muscle training alone, and Group C: Usual training session. The difference within the groups after four weeks of the intervention was analyzed using Paired T-test, while the differences between intervention groups were analyzed using repeated measure two-way ANOVA. Both the intervention groups (Group A and B) showed significant improvement after four weeks of intervention, whereas in group comparison, Group A showed tremendous improvement in swimming performance (F (17,238) = 8.385, p<0.05, np2 = 0.375). Thus, the current study has proven that the combination of respiratory muscle training with individualized training could further enhance the swimming performance in terms of heart rate, Vo2 max, stroke volume, perceived exertion, and SWOLF score. Future studies on athletic swimmers with a larger sample size are recommended to further examine the individualized training approach.

In-Season Strength Training in Elite Junior Swimmers: The Role of the Low-Volume, High-Velocity Training on Swimming Performance.

The aim of this study was to analyze the effect of long-term combined strength training (ST) and plyometrics on strength, power and swimming performances in elite junior swimmers during a competitive season. Ten elite junior swimmers (5 women and 5 men) completed the study (age: 16.6 ± 0.7 years; mass: 62.2 ± 5.4 kg; stature: 1.70 ± 0.07 m). The participants trained twice a week during 20 weeks. The ST program consisted of upper- and lower limbs exercises with low loads and low volume, lifting the load at maximal intended velocity. The effect of the training protocol was assessed using the 1RM in the full squat (SQ) and bench press (BP), jump height (CMJ), the maximal number of repetitions completed in the pull-up (PU) exercise and time during 50-m freestyle. Training program resulted in significant improvements in CMJ (12.1%, ES: 0.57), maximal dynamic strength in the SQ (16.4%, ES: 0.46) and BP (12.1%, ES: 0.34) exercises, the maximum number of repetitions completed during the PU test (90.7%, ES: 0.57) and swimming performance (-3.9%, ES: 0.45). There were no significant differences between both genders. The relative changes in swimming performance showed significant relationship with the relative changes in 1RM of SQ for pooled data (r=-0.66, p<0.05) and the relative changes in the PU exercise in female swimmers (r=-0.99, p<0.05). Therefore, coaches and strength and conditioning professionals should consider including in-season dry-land ST programs within the training routine in order to obtain further improvements in swimming performance.

Kinematic Differences in Shoulder Roll and Hip Roll at Different Front Crawl Speeds in National Level Swimmers.

Andersen, JT, Sinclair, PJ, McCabe, CB, and Sanders, RH. Kinematic differences in shoulder roll and hip roll at different front crawl speeds in National Level Swimmers. J Strength Cond Res 34(1): 20-25, 2020-Dry-land strength training is a common component of swimming programs; however, its efficacy is contentious. A common criticism of dry-land strength training for swimming is a lack of specificity. An understanding of movement patterns in swimming can enable dry-land strength training programs to be developed to elicit adaptations that transfer to improvements in swimming performance. This study aimed to quantify the range and velocity of hip roll, shoulder roll, and torso twist (produced by differences in the relative angle between shoulder roll and hip roll) in front crawl at different swimming speeds. Longitudinal torso kinematics was compared between sprint and 400-m pace front crawl using 3D kinematics of 13 elite Scottish front crawl specialists. The range (sprint: 78.1°; 400 m: 61.3°) and velocity of torso twist (sprint: 166.3°·s; 400 m: 96.9°·s) were greater at sprint than 400-m pace. These differences were attributed to reductions in hip roll (sprint: 36.8°; 400 m: 49.9°) without corresponding reductions in shoulder roll (sprint: 97.7°; 400 m: 101.6°) when subjects swam faster. Shoulder roll velocity (sprint: 190.9°·s; 400 m: 139.2°·s) and hip roll velocity (sprint: 75.5°·s; 400 m: 69.1°·s) were greater at sprint than 400-m pace due to a higher stroke frequency at sprint pace (sprint: 0.95 strokes·s; 400 m: 0.70 strokes·s). These findings imply that torques acting to rotate the upper torso and the lower torso are greater at sprint than 400-m pace. Dry-land strength training specificity can be improved by designing exercises that challenge the torso muscles to reproduce the torques required to generate the longitudinal kinematics in front crawl.

Kinematics Research Progress of Swim-start on the New Start Block

The new starting block by Omega firstly appeared in Beijing Olympic Games since the FINA (Fédération Internationale de Natation) amended the rule (OSB11, Corgémont, Switzerland). And this new start block gave rise to the researchers and academics focused more on the start techniques on this new start block. The aim of this study is to summarize the current literature regarding the kinematics research progress of swimming start on this new start block and find the proper swim-start to optimize the swimming performance. The aim of this study is to provide insight into the improvement of swimming performance on the new start block by kinematics view for coaches and athletes. Results suggest that the KS is superior to the TS and GS. With the introduction of the OSB11 starting plate, swimmers need to quickly modify and adjust their techniques to take advantage of the new swimming start plate during normal training. The swimmers should not only enhance their speed training and speed training methods but also strengthen the core and lower limb strength to obtain the best take-off forces and horizontal velocity.

Intermittent hypoxic training improves anaerobic performance in competitive swimmers when implemented into a direct competition mesocycle.

The main objective of this research was to evaluate the efficacy of intermittent hypoxic training (IHT) on anaerobic and aerobic capacity and swimming performance in well-trained swimmers. Sixteen male swimmers were randomly divided into a hypoxia (H) group (n = 8), which trained in a normobaric hypoxia environment, and a control (C) group (n = 8), which exercised under normoxic conditions. However, one participant left the study without explanation. During the experiment group H trained on land twice per week in simulated hypoxia (FiO2 = 15.5%, corresponding to 2,500 m a.s.l); however, they conducted swim training in normoxic conditions. Group C performed the same training program under normoxic conditions. The training program included four weekly microcyles, followed by three days of recovery. During practice sessions on land, the swimmers performed 30 second sprints on an arm-ergometer, alternating with two minute high intensity intervals on a lower limb cycle ergometer. The results showed that the training on land caused a significant (p<0.05) increase in absolute maximal workload (WRmax) by 7.4% in group H and by 3.2% in group C and relative values of VO2max by 6.9% in group H and 3.7% in group C. However, absolute values of VO2max were not significantly changed. Additionally, a significant (p<0.05) increase in mean power (Pmean) during the first (11.7%) and second (11.9%) Wingate tests was only observed in group H. The delta values of lactate concentration (ΔLA) after both Wingate tests were significantly (p<0.05) higher in comparison to baseline levels by 28.8% in group H. Opposite changes were observed in delta values of blood pH (ΔpH) after both Wingate tests in group H, with a significant decrease in values of ΔpH by 33.3%. The IHT caused a significant (p<0.05) improvement in 100m and 200m swimming performance, by 2.1% and 1.8%, respectively in group H. Training in normoxia (group C), resulted in a significant (p<0.05) improvement of swimming performance at 100m and 200m, by 1.1% and 0.8%, respectively. In conclusion, the most important finding of this study includes a significant improvement in anaerobic capacity and swimming performance after high-intensity IHT. However, this training protocol had no effect on absolute values of VO2max and hematological variables.

Effects of Low-Volume, High-Intensity Training on Performance in Competitive Swimmers: A Systematic Review.

Nugent, FJ, Comyns, TM, Burrows, E, and Warrington, GD. Effects of low-volume, high-intensity training on performance in competitive swimmers: a systematic review. J Strength Cond Res 31(3): 837-847, 2017-The purpose of this systematic review was to examine the extent and quality of the current research literature to determine the effects of low-volume, high-intensity training (HIT) on physiological performance and swimming performance in competitive swimmers. The methodology followed the preferred reporting items for systematic review and meta-analysis protocol. A search of relevant databases and conference proceedings was performed until December 2015. The inclusion criteria were (a) competitive swimmers, (b) ≥4 weeks HIT intervention, (c) comparison group had to involve a higher training volume, (d) outcome measures of physiological and swimming performance, and (e) all experimental study designs. Quality assessment was performed using the Quality Index checklist. Results indicate that of the 538 studies retrieved, 7 studies met the inclusion criteria. Six of the 7 studies found that an HIT intervention resulted in significant improvements in physiological performance. Four of the 7 studies found that HIT resulted in significant improvements in swimming performance, whereas none of the 7 studies resulted in a reduction in physiological or swimming performance. Despite the positive findings of this review, the short study duration is a limitation to a number of studies. The current evidence on the effects of HIT on performance is promising; however, it is difficult to draw accurate conclusions until further research has been conducted.

Improvement of swimming performance of crawl stroke for the swimming humanoid robot

Improvement of swimming performance of crawl stroke for the swimming humanoid robot

Effects of Short-Interval and Long-Interval Swimming Protocols on Performance, Aerobic Adaptations, and Technical Parameters: A Training Study.

Dalamitros, AA, Zafeiridis, AS, Toubekis, AG, Tsalis, GA, Pelarigo, JG, Manou, V, and Kellis, S. Effects of short-interval and long-interval swimming protocols on performance, aerobic adaptations, and technical parameters: A training study. J Strength Cond Res 30(10): 2871-2879, 2016-This study compared 2-interval swimming training programs of different work interval durations, matched for total distance and exercise intensity, on swimming performance, aerobic adaptations, and technical parameters. Twenty-four former swimmers were equally divided to short-interval training group (INT50, 12-16 × 50 m with 15 seconds rest), long-interval training group (INT100, 6-8 × 100 m with 30 seconds rest), and a control group (CON). The 2 experimental groups followed the specified swimming training program for 8 weeks. Before and after training, swimming performance, technical parameters, and indices of aerobic adaptations were assessed. ΙΝΤ50 and ΙΝΤ100 improved swimming performance in 100 and 400-m tests and the maximal aerobic speed (p ≤ 0.05); the performance in the 50-m swim did not change. Posttraining V[Combining Dot Above]O2max values were higher compared with pretraining values in both training groups (p ≤ 0.05), whereas peak aerobic power output increased only in INT100 (p ≤ 0.05). The 1-minute heart rate and blood lactate recovery values decreased after training in both groups (p < 0.01). Stroke length increased in 100 and 400-m swimming tests after training in both groups (p ≤ 0.05); no changes were observed in stroke rate after training. Comparisons between groups on posttraining mean values, after adjusting for pretraining values, revealed no significant differences between ΙΝΤ50 and ΙΝΤ100 for all variables; however, all measures were improved vs. the respective values in the CON (p < 0.001-0.05). In conclusion, when matched for distance and exercise intensity, the short-interval (50 m) and long-interval (100 m) protocols confer analogous improvements in swimming performance, in stroke cycle parameters, and in indices of aerobic adaptations after 8 weeks of training.

The Relationship Between Dolphin Kick Movement And Underwater EMG Of Lower Leg Muscles In Competitive Swimmers

Improvement in swimming performance is not only associated with stroke technique but also with the gliding movement during the start and turn phases. The underwater dolphin kick movement during the start and turn phases is important for improving total race time in modern swimming. PURPOSE: The study was designed to analyze the findings of underwater electromyography of lower limb muscles during the underwater dolphin kick movement in competitive collegiate swimmers. METHODS: Six healthy male collegiate swimmers volunteered to participate in this study. The subjects performed underwater gliding movement at maximum speed after pushing off from the start wall. In addition, three types of underwater dolphin kick movement [Control (C): maximum effort kick; Build-up (BU): small-to-large kick; and Dynamic (D): large kick) were performed with maximum effort. The subjects were monitored through an underwater video camera with a sampling frequency of 60 Hz in the sagittal plane to measure the angular displacement of their different joints. A wireless electromyography system (Biolog DL-5000, S&ME, Japan) was used to collect the muscle activities from the vastus lateralis, hamstrings, tibialis anterior, and gastrocnemius. Speed Meter (Vine Co., Japan) was used to measure swimming speed, and a motion analysis system (Frame-DIAS4; DKH, Japan) was used to digitize body landmarks. RESULTS: Among the underwater dolphin kick movement types, the BU kick was the fastest (BU: 1.67 m/s; C: 1.65 m/s; and D: 1.65 m/s). The rectified EMG findings showed that gastrocnemius and hamstrings muscle activities of elite swimmers were higher than non-elite swimmers during these movements. However, elite swimmers had no muscle activity in the tibialis anterior. CONCLUSIONS: The present study results suggested that the angular displacement of the knee joints gradually increases during underwater dolphin kick movement. In addition, the muscle activity of the hamstrings and gastrocnemius increase during underwater dolphin kick movement. However, the muscle activity of tibialis anterior was inhibited during these movements. Our results also suggested that swimmers experienced a large propulsion force and a small resistance force with the help of these movements.

Effect of BDKRB2 Gene -9/+9 Polymorphism on Training Improvements in Competitive Swimmers.

The aim of the study was to investigate the possible association between the BDKRB2 gene and training-induced improvements in swimming performance in well-trained swimmers. One hundred Polish swimmers (52 men and 48 women, aged 18.1 ± 1.9 years), who competed in national and international competitions at middle- (200 m) and long-distance events (≥400 m), were included in the study. Athletes' genotype and allele distributions were analyzed in comparison to 230 unrelated sedentary subjects, who served as controls, with the χ test. All samples were genotyped for the BDKRB2 -9/+9 polymorphism by polymerase chain reaction. The effects of genotype on swimming performance improvements were analyzed with two-way (3 × 2; genotype × time) analysis of variance with metric age as a covariate. The training period of 1.9 ± 0.4 years had a significant (p < 0.01) effect on swimming performance, both in female and male athletes. Both in female and male athletes, the BDKRB2 gene -9/+9 polymorphism had no significant effect on swimming performance. An interaction effect of BDKRB2 gene -9/+9 polymorphism × time was found for swimming performance only in male athletes. Post hoc analyses showed that swimmers with the +9/+9 BDKRB2 genotype had a greater improvement in swimming performance than swimmers with the -9/+9 polymorphism (p ≤ 0.05). No interaction effects for gender × BDKRB2 gene -9/+9 polymorphism were found for either swimming performance or improvement in swimming performance. These results suggest that the response to long-term exercise training could be modulated by the BDKRB2 gene -9/+9 polymorphism in male athletes. In well-trained swimmers, BDKRB2 gene variation was not found to be an independent determinant of swimming performance.

Effect of Swim Cap Surface Roughness on Passive Drag.

In the last decade, great attention has been given to the improvements in swimming performance that can be obtained by wearing "technical swimsuits"; the technological evolution of these materials only marginally involved swim caps production, even if several studies have pointed out the important role of the head (as main impact point with the fluid) on hydrodynamics. The aim of this study was to compare the effects on passive drag (Dp) of 3 swim cap models: a smooth silicon helmet cap (usually used during swimming competitions), a silicon helmet cap with "dimples," and a silicon helmet cap with "wrinkles." Experiments were performed on 10 swimmers who were towed underwater (at a depth of 60 cm) at 3 speeds (1.5, 1.7, and 1.9 m·s) and in 2 body positions: LA (arms above the swimmer's head) and SA (arms alongside the body). The Dp values obtained in each trial were divided by the square of the corresponding speed to obtain the speed-specific drag (the k coefficient = Dp/v). No differences in k were observed among swim caps in the LA position. No differences in k were observed between the smooth and dimpled helmets also in the SA position; however, the wrinkled swim cap helmet showed a significant larger k (4.4%) in comparison with the model with dimples, when the swimmers kept their arms alongside the body (in the SA position). These data suggest that wearing a wrinkled swim cap helmet can be detrimental to performance at least in this specific position.

Biomechanical analysis of the gliding and dolphin kick movement in competitive swimmers

Introduction: The improvement of swimming performance is related not only to the effect of stroking but also dolphin kick movement after the start and the turn phase. The dolphin kick movement after the start and turn phases are important for the total race time in modern swimming. We hypothesized that acceleration by dolphin kick movement would assist to increase the swim speeds, consequently, swimmers need to keep a better body position and higher speed after optimal dolphin kick movement. The purpose of this study was to biomechanical analysis of the gliding and dolphin kick movement in competitive swimmers.

Estimate of propulsive force in front crawl swimming in young athletes

BackgroundImprovement in swimming performance involves the dynamic alignment of the body in liquid, technical skill, anthropometric characteristics of athletes, and the ability to develop propulsive force. The aim of this study was to assess the relationships between the propulsive force during swimming and arm muscle area (AMA) and propose an equation to estimate the propulsive force in young swimmers by measuring their AMA.MethodsStudy participants were 28 male swimmers (14 ± 1.28 years) registered in the Brazilian Federation of Aquatic Sports. Their AMA was estimated by anthropometry and skinfold measurement, and the propulsive force of their arm (PFA) was assessed by the tied swimming test. The Durbin-Watson (DW) test was used to verify residual independence between variables (PFA and AMA). A Pearson correlation investigated potential associations between the variables and then a linear regression analysis was established. The Bland-Altman method was used to compare the values found between PFA and propulsive force-estimated (PFE). A paired Student’s t-test was used to analyze the difference in PFE with and without the constant and the coefficient of variation (CV) to estimate the magnitude of a real change between these forces.ResultsThere was a significant positive correlation between the variables AMA and PFA (r = 0.68, P < 0.001). The linear regression showed a value of R2 = 0.470. There were no significant differences when comparing PFA and PFE (95% confidence interval: −8.903 to 9.560 kgf). To verify if there was a correlation between these variables, a new linear regression analysis found a value of R2 = 0.668, which confirms an equivalence between PFA and PFE, as CV showed 4% of magnitude.ConclusionThe results of this study suggest the existence of a relationship between levels of PFA and muscle mass, however, this relationship becomes more evident the longer the AMA, which allows the development of an equation to estimate the propulsive force of young swimmers.

Lactate Threshold and Performance Adaptations to 4 Weeks of Training in Untrained Swimmers: Volume Vs. Intensity

The purpose of this study was to investigate the impact of 4 weeks of high-intensity vs. high-volume swim training on lactate threshold (LT) characteristics and performance. Thirteen untrained swimmers with a mean age of 19.0 ± 0.5 undertook an incremental swimming test before and after 4 weeks of training for the determination of LT. Performance was evaluated by a 50-m maximum freestyle test. The swimmers were assigned to 1 of each of 2 training groups. The high-intensity group (n = 6) focused on sprint training (SP) and swam a total of 1,808 ± 210 m. The high-volume group (n = 7) followed the same program as the SP group but swam an additional 1,100 m (38% more) of endurance swimming (SP + End). A training effect was evident in both groups as seen by the similar improvements in sprint performance of the 50-m maximum time (p < 0.01), peak velocity increases and the lower value of lactate at the individual LTs (p < 0.01). Lactate threshold velocity improved only in the SP + End group from 1.20 ± 0.12 m·s(-1) pretraining to 1.32 ± 0.12 m·s(-1) posttraining (p = 0.77, effect size = 1, p < 0.01), expressed by the rightward shifts of the individual lactate-velocity curves, indicating an improvement in the aerobic capacity. Peak lactate and lactate concentrations at LT did not significantly change. In conclusion, this study was able to demonstrate that 4 weeks of either high-intensity or high-volume training was able to demonstrate similar improvements in swimming performance. In the case of lack of significant changes in lactate profiling in response to high-intensity training, we could suggest a dissociation between the 2.