100-m Freestyle Research Articles

The hierarchical organization of arm stroke in a 400-m freestyle swimming race

PurposeArm stroke is a key variable of successful performance in front crawl swimming. In the present study, the effects of the arm stroke on the front crawl swimming performance were analysed by considering the complementarity of macroconsistency and micro-variability in the arm stroke as a hierarchically organized adaptive system. In this case, consistency is necessary to achieve outcomes reliably, and variability is fundamental for coping with environmental instability.MethodsDisplacements of swimmers (<i>n</i> = 31) who competed in the 400-m freestyle race of the Paulista Master Championship were captured in 4 moments (partial races 1–4). From the aerial and aquatic phases of the left and right arm strokes, macrostructure (components’ relative timing) and microstructure (components’ overall time) had their variability rates calculated for all partial races on the basis of the biological coefficients of variation.ResultsIt was revealed that swimmers: (i) increased consistency of macrostructure related to the left arm aerial phase stroke in the final race; (ii) maintained consistency of microstructure across races; and (iii) presented macrostructure with inferior rate of variability to the microstructure in the final race.ConclusionsGiven these results, coaches should emphasize instruction for swimmers to maintain the temporal relationship among arm stroke components (macrostructure) rather than focus on the components themselves (microstructure).

COMPARATIVE ANALYSIS OF COMPETITIVE SWIMMING BETWEEN EUROPEAN AND B&H SWIMMERS IN THE 50M DISCIPLINE

The subject of the research is competitive swimming in Europe (EUR) and Bosnia and Herzegovina (B&H) from 2008 to 2018, discipline of 50m freestyle for male seniors. The problems of the research are trends, dynamics and differences between swimmers from Bosnia and Herzegovina and swimmers from Europe. The objectives of the research are: 1.To identify trends in swimming development in EUR and B&H from 2008 to 2018. 2. To determine the statistical significance of differences between EUR swimmers and B&H swimmers. 3. To evaluate the results for 2020 based on linear functions. In accordance with the set goals of the research, appropriate statistical methods and tests were applied, which enabled an exact answer to the set hypotheses and goals. The variables were being monitored in this study: 1.The time of the eight finalists 2. The time of the first three swimmers. 3. The Winner time. 4. The Record time. Based on the achieved results, it can be validly and reliably concluded that there is generally an improvement in results for EUR swimmers and B&H swimmers. It is statistically proven that there is a significant difference in the achieved results. European swimmers showed better results that were statistically significant. Linear functions i.e trends indicate that there is a small difference. There are more reasons for lagging of B&H’s swimmers behind the European swimmers. In the post-war period there are no elementary material, professional, coaching and other assumptions that enable better results either in swimming or in other sports in Bosnia and Herzegovina

Starting Fever and Its Relationship with 50m Freestyle Swimming in Youth

The research aimed at identifying the relationship between starting fever and 50m freestyle achievement in youth swimmers by measuring this type of anxiety as a psychological variable and its relationship with achievement as a physical variable. The researchers used the descriptive method on (10) swimmers from Baghdad clubs while the pilot study was conducted on (4) swimmers. They used a starting fever scale in the form of a questionnaire presented to the subjects before an hour from the race. The data was collected and treated using proper statistical operations to conclude a relationship between start fever and 50m freestyle achievement in youth swimmers. Finally, the researchers recommended paying more attention to start fever due to its great importance in 50m freestyle achievement as well as making similar studies on other activities that require speed performance and achievement of swimmers.

Analysis of end-spurt behaviour in elite 800-m and 1500-m freestyle swimming

To analyse the influence of distance, time point of competition, round and finishing position on end-spurt behaviour in swimming. Race results in 800-m and 1500-m freestyle swimming from the last 8 World Championships and 5 Olympic Games (1998–2016) including 1433 races and 528 swimmers were obtained. The end-spurt for each race was determined by means of an End-Spurt Indicator (ESI). The ESI was calculated by dividing the difference between the swim velocity of the last lap (SVLL) and the mean swim velocity of the middle part of the race (SVMP) by the respective individual standard deviation of SVMP. Subsequently, ESI was used as a dependent variable and influences were analysed using a linear mixed model with fixed effects for distance, time point of competition, round and finishing position. An end-spurt was evident in most swims for both race distances. The mean change in swim velocity between the middle part of the race and the last lap was 0.06 ± 0.02 m/s (1.2 ± 0.2 s) in the 800-m and 0.07 ± 0.02 m/s (1.5 ± 0.2 s) in the 1500-m. The finishing position within a race significantly affected the ESI (P < .001, t = 7.28). Specifically, when analysing finals only, ESI was significantly greater in medallists (5.76; quantile: 3.61 and 8.06) compared to non-medallists (4.06; quantile: 1.83 and 6.82; P = .001). The between-subject standard deviation was 1.66 (Cl: 1.42–1.97) with a relative variance component of 23%, while 77% of ESI variance remained unexplained. This is the first study using a newly developed indicator of end-spurt behaviour demonstrating that particularly medallists have a more pronounced end-spurt compared to non-medallists.

A Novel Method to Characterize the Pacing Profile of Elite Male 1500-m Freestyle Swimmers

Pacing, or the distribution of energy expenditure, is particularly important in swimming; however, there is limited research examining pacing profiles in long-distance freestyle events. This study aimed to characterize the pacing profiles of elite male 1500-m freestyle swimmers using a novel method to provide a detailed analysis of different race segments. The race data for 327 male 1500-m freestyle long-course races between 2010 and 2019 were analyzed retrospectively. The raw 50-m split times for each lap were converted to a percentage of overall race time. The races were classified as a fast-, average-, or slow-start strategy (laps 1-2); as an even, negative, or positive pacing strategy (laps 3-28); and as a fast-, average-, or slow-finish strategy (laps 29-30) to give an overall pacing profile. Slow- and average-start strategies were associated with faster overall 1500-m times than a fast-start strategy (mean = -21.2s; 90% confidence interval, -11.4 to -32.3s, P = .00). An even pacing strategy in laps 3 to 28 yielded faster overall 1500-m times than a positive pacing strategy (-8.4s, -3.9 to -13.0s, P = .00). The overall 1500-m times did not differ substantially across the finish strategies (P = .99). The start strategy differed across age groups and nationalities, where younger swimmers and swimmers from Australia and Great Britain typically spent a lower percentage of race time in laps 1 to 2 (faster start strategy; -0.10%, -0.01% to -0.23%, P ≤ .02). Adopting a relatively slower start strategy helps conserve energy for the latter stages of a 1500-m freestyle race.

Proposal of a Conditioning Activity Model on Sprint Swimming Performance.

This study aimed to propose a conditioning activity (CA) model to stimulate improvement on neuromuscular responses, mechanical parameters and for the 50-m freestyle swimming. Thirteen male swimmers (19 ± 3 years and performances of 77% in relation to World Championship records) performed four CA protocols followed by a maximum performance in the 50-m freestyle. In the first protocol (P1) swimmers performed a standard warm-up (∼15 min); in the second protocol (P2) lunges (3 × 85% of the one-repetition maximum); in the third (P3) pull-ups (3 maximum repetitions) and box jumps 40 cm high and 60 cm deep (1 × 5 with 10% of the corporal weight); and in the fourth protocol (P4) a combination of exercises from the second and third protocols. CA protocols had no effect on the standard warm-up. However, P2 performance (27.01 ± 1.25 s) was similar to P1 (27.01 ± 1.18 s) and presented higher positive effects in mechanical parameters for the swim start performance in comparison to other protocols, contributing to improvements in the 50-m freestyle. In addition, turnaround time also had a negative effect, mainly in P3 (3.12 ± 0.28 s), signaling the improvement of this variable in all protocols (P1: 3.30 ± 0.38 s; P2: 3.17 ± 0.30 s; P4: 3.17 ± 0.34 s). P2 (after: 80 ± 11%; before: 82.7 ± 9.9%) and P3 (after: 82.7 ± 9.9%; before: 85.1 ± 9.7%) presented a possible positive effect on the percentage of voluntary activation in relation to P1 (after: 79.3 ± 10.7%; before: 76.3 ± 12%). In conclusion, the proposed conditioning activity protocols were not efficient for performance improvement in the 50-m freestyle compared to the standard model and seem to specifically influence each phase of the event.

Maturity-related developmental inequalities in age-group swimming: The testing of ‘Mat-CAPs’ for their removal

ObjectivesTo (1) examine the association between maturity timing and performance-based selection levels in (N=708) Australian male 100-m Freestyle swimmers (12–17 years); (2) identify the relationship between maturation status and 100-m Freestyle performance; and (3) determine whether Maturation-based Corrective Adjustment Procedures (Mat-CAPs) could remove maturation-related differences in swimming performance. MethodsIn Part 1, maturity timing category distributions (‘Early’, ‘Early Normative’, ‘Late Normative’ and ‘Late’) for ‘All’, ‘Top 50%’ and ‘25%’ of raw swimming times were examined within and across age-groups. In Part 2, multiple regression analyses quantified the relationship between maturity offset (YPHV) and swimming performance. In Part 3, sample-based maturity timing category distributions were examined based on raw and correctively adjusted swim times for 12–17 year old age-groups. ResultsBased on raw swim times, a high prevalence of ‘Early-maturing’ swimmers, with large effect sizes was identified (e.g., 14 years ‘All’ — χ2 (3, 151=111.98, p<0.001; ‘Early’ v ‘Late’ OR=82.0 95%CI=4.77, 1409.9); while a complete absence of ‘Late-maturers’ was apparent in the sample (N=708). When maturity categories were re-defined based on sample mean±standard deviation, and when using the expected curvilinear trendline identified in Part 2, Mat-CAPs mitigated maturity timing biases across all age-groups and selection levels, and removed the Freestyle performance advantage afforded by advanced maturity timing and status. ConclusionsRemoving the influence of maturation-related developmental differences could help improve youth swimmer participation experiences and improve the accuracy of identifying genuinely skilled age-group swimmers.

Analytical Comparative Study of Some Kinematic Variables Affecting the Distances of 200 m. Freestyle Race

The study aimed at identifying some kinematic variables affecting the distances of 200m freestyle race among the swimmers of the Specialized School for Swimming. Three (3) swimmers have been intentionally chosen to be the subjects of the study. The kinematic variables of each player have been extracted by the motor analysis (kinovea) program and their data values then compared. In light of the results, the researcher found out clear big differences in the values of these variables among the swimmers themselves and between each distance of the race distances for each swimmer which led to a big variation in the achievement (final time). A matter that requires reforming procedures in the technical performance and physical characteristics development for the swimmers of the Specialized School in 200m freestyle event in order to reduce the final time (improving achievement).

Does Social Media Use on Smartphones Influence Endurance, Power, and Swimming Performance in High-Level Swimmers?

ABSTRACT Objective: This study aimed to investigate the repeated effect of social media on smartphones immediately before training sessions on inhibitory control (Stroop task), endurance (tethered swimming), countermovement jump (CMJ), and swimming performance (50, 100, and 400-m freestyle) in high-level female swimmers. Methods: It is a randomized and experimental investigation with parallel groups. Twenty-two participants underwent the eight weeks of the experiment. The swimmers (eight to twelve sessions per week with 15.9 ± 1.6 hours/week, and training experience of ~ 5.6 years) were randomized in two groups: control (CON, n = 11) and smartphone (SMA, n = 11). Immediately before each training session, the CON group watched videos about Olympic Games for 30-min. The SMA group used social network smartphone apps during 30-min. The inhibitory control, endurance, CMJ, and swimming performance were measured before and after the eight weeks of intervention. Results: No group x time interaction for 50-m freestyle (F (4, 18) = 1.04; p = .33; η2 = 0.09) and CMJ performance (F (4, 18) = 0.31; p = .58; η2 = 0.03) was found. Both experimental groups improved CMJ (F (2, 20) = 8.71; p = .01; η2 = 0.46). Only the CON group improved the 100-m (p = .02), 400-m freestyle (p = .01), and endurance performance (p = .01). The CON group improved the inhibitory control response (p = .01). Conclusion: It is concluded that the repeated effect of social media on smartphones immediately before swimming training sessions might reduce or nullify training gains on swimming and endurance performance.

Smartphone Use Among High Level Swimmers Is Associated With Mental Fatigue and Slower 100- and 200- but Not 50-Meter Freestyle Racing.

Discovering any performance degradation effect of racing swimmers' use of social media smartphone apps might lead to new training and race preparation protocols, including pre-meet smartphone avoidance. This study's objective was to analyze the performance effects of using smartphone social media apps on the 50, 100, and 200-m freestyle among 25 high-level swimmers. Each participant performed the three race distances in two conditions: with smartphone app exposure (50-MF, 100-MF, and 200-MF) and without (50-CON, 100-CON, and 200-CON). We randomized the order of these two conditions across participants. While smartphone app use was not associated with statistically significant performance differences on the shortest race (50CON versus 50MF), a repeated measures ANOVA showed a significant condition × time interaction for the swimmers'100-m freestyle performance (p = 0.01), with a significantly slower performance following smartphone app use evident in the last half of this race (p = 0.02) but not in the first half (p = 0.41). We also found a condition × time interaction in the same direction (slower for swimmers who used the smartphone app) for the 200-m freestyle performance (p = 0.01), with the slower performance occurring in the second (p = 0.01) but not the first (p = 0.91), third (p = 0.07) or fourth (p = 0.06) quarters of this race. Thus, prolonged smartphone social media app use was associated with reduced performance from elite swimmers on the 100- and 200- but not the 50-m freestyle.

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.

The Effect of Kinesio Taping on Spasticity: A Randomized, Controlled, Double-Blind Pilot Study in Para-Swimmers.

Kinesio Taping (KT) produces several clinical effects, including pain relief, edema absorption, and improved muscle performance. When applied in the insertion to origin mode, it is claimed to inhibit excessive muscle contractions. Investigate whether KT applied in the insertion to origin mode could reduce the exaggerated reflex contraction of spastic muscles. Randomized crossover trial, with a restricted block randomization. Clinical laboratory and swimming pool. Seven para-swimmers. KT, applied in inhibitory mode, to investigate its effect on knee extensor spasticity. Primary outcome is stretch reflex, as compared with clinical assessment of spasticity by Modified Ashworth Scale and self-perceived spasticity by numeric rating scale. Secondary outcomes were Medical Research Council for strength of knee extensor muscles and chronometric swimming performance in 100-m freestyle. KT significantly decreased the amplitude of stretch reflex (P < .001), whereas the placebo treatment produced no significant effects. Scores of Medical Research Council for strength and Modified Ashworth Scale did not change after KT, whereas numeric rating scale scores for spasticity significantly decreased (P = .001). The swimming performance was significantly improved after KT treatment as compared with baseline (P < .01). This exploratory study performed on para-athletes suggests that KT could reduce spasticity. This outcome has 3-fold implications for clinical, rehabilitation, and sport methods.

Aerobic Interval Training in Freestyle Swimming

This research was conducted so that the endurance and speed of swimming athletes can be increased and prepare young swimmers to be able to reach the time requirements in following the provincial championship. Problems found in the field, athletes train in the conventional way, and training programs are arranged based on the trainer's experience. This is the basis for the use of aerobic interval training for young swimmers because it can form training early by using a proven theoretical basis that can increase the time in swimming. The research began by revealing the ability of the freestyle athlete in the swimming club through aerobic interval training in order to have maximum endurance and speed. This training involved 18 athletes in the age range of 10-15 years. The success of the training is known through data obtained from the best time during aerobic training in the 50m freestyle swimming. Swimming time measurement uses a stopwatch so that freestyle swimming time is known before and after training. Time achievement that has been obtained is done different tests to see the effect of interval training on swimming time speed. The final measurement results show that the athlete's time achievement in freestyle swimming changes after being given aerobic interval training. The results of this study will support the achievement of best time young swimmers to take part in the National Sports Week by continuing training using theoretically and empirically tested training programs.

Tethered Swimming Ineffective As Post Activation Potentiation Procedure For 50-m Swimming Performance In Adolescent Swimmers

PURPOSE: The aim of the study was to investigate if tethered swimming (TS) performed 8 min before a 50-m freestyle swimming sprint could be an effective post-activation potentiation (PAP) method to improve performance. METHODS: Regional level male adolescent swimmers (age: 13.0±2.0 y; height: 161.1±12.4 cm; body mass: 52.5±9.5 kg) performed two trial conditions (1 experimental (TS), 1 control (CTR)) on different days. The control group performed a standardized 1200-m warm-up followed by 8 min of rest and a maximal 50 m freestyle swimming sprint. The experimental group performed the same protocol with an added TS component at the end of warm-up, which consisted of 3 x 10 s maximal effort of tethered swimming with 1 min rest in-between sprints. Performance (time-trial), selected biomechanical (stroke length), physiological (blood lactate concentrations, heart rate), psychophysiological (ratings of perceived exertion (RPE)) variables and Counter movement jump (CMJ) flight-time were collected. RESULTS: Pre-performance tethered swimming had no effect on swimming time, RPE, stroke rate or CMJ flight time. Before the 50 m race, blood lactate concentrations were significantly higher in TS than in control condition (p=0.03, η2 = 0.62). One minute after the 50 m sprint, heart rate was significantly higher in the control condition compared to the TS (P =0.046, η2 = 0.27). CONCLUSIONS: The present study showed that 3 x 10 s tethered swimming performed 8 min prior to the event did not impact the 50 m sprint performance in young swimmers and may not be considered an effective PAP stimulus.

Effect of Tethered Swimming as Postactivation Potentiation on Swimming Performance and Technical, Hemophysiological, and Psychophysiological Variables in Adolescent Swimmers

To investigate whether tethered swimming (TS) performed 8 minutes before a 50-m freestyle swimming sprint could be an effective postactivation potentiation method to improve performance in young swimmers. Fourteen regional-level male adolescent swimmers (age 13.0 [2.0]y; height 161.1 [12.4]cm; body mass 52.5 [9.5]kg) underwent 2 trial conditions in a randomized and counterbalanced order (1 experimental [TS], 1 control) on different days. During the experimental session, the participants performed a standard warm-up of 1200m followed by a TS exercise, which consisted of 3 × 10-second maximal efforts of TS with 1-minute rests between bouts. In the control condition, the warm-up phase was immediately followed by 200m at a moderate pace (same duration as the TS in the experimental session). Performance (time trial); biomechanical (stroke length), physiological (blood lactate concentrations), and psychophysiological (ratings of perceived exertion) variables; and countermovement-jump (CMJ) flight time were collected. TS warm-up had no significant effect on 50-m swimming performance (P = .27), postexercise ratings of perceived exertion, stroke length, or CMJ flight time (P ≥ .05). Blood lactate concentrations significantly increased at the end of the warm-up in the TS condition only (interaction effect: F1.91,29.91 = 4.91, P = .01, η2 = .27) and after the 50-m trial in both conditions (F1.57,20.41 = 62.39, P = .001, η2 = .82). The present study demonstrated that 3 × 10-second TS exercises performed 8 minutes prior to the event did not affect ratings of perceived exertion, stroke length, or CMJ flight time. In addition, tethered swimming did not affect 50-m freestyle sprint performance in young swimmers.

Pacing and Performance in Swimming: Differences Between Individual and Relay Events.

Although pacing is considered crucial for success in individual swimming events, there is a lack of research examining pacing in relays. The authors investigated the impact of start lap and pacing strategy on swimming performance and whether these strategies differ between relays and the corresponding individual event. Race data for 716 relay (4 × 200-m freestyle) finals from 14 international competitions between 2010 and 2018 were analyzed retrospectively. Each swimmer's individual 200-m freestyle season's best time for the same year was used for comparison. Races were classified as a fast, average, or slow start lap strategy (lap 1) and as an even, negative, or positive pacing strategy (laps 2-4) to give an overall race strategy, for example, average start lap even pacing. A fast start lap strategy was associated with slower 200-m times (range 0.5-0.9s, P ≤ .04) irrespective of gender, and positive pacing led to slower 200-m (0.4-0.5s, P ≤ .03) times in females. A fast start lap strategy led to positive pacing in 71% of swimmers. Half of the swimmers changed pacing strategy, with 13% and 7% more female and male swimmers, respectively, displaying positive pacing in relays compared with individual events. In relays, a fast start lap and positive pacing was utilized more frequently by swimmers positioned on second to fourth relay legs (+13%) compared with lead-off leg swimmers (+3%). To maximize performance, swimmers should be more conservative in the first lap and avoid unnecessary alterations in race strategy in relay events.

Hypoxic Training Is Beneficial in Elite Athletes.

There is no doubt that many hypoxic conditions or prolonged exposures to altitude result in “biological costs of hypoxic adaptations that outweigh their benefits” (1), particularly in endurance athletes exposed to a) exercise-induced arterial hypoxemia leading to a larger decrease in VO2max and aerobic endurance; b) increased sympathetic activity and decreased baroreflex sensitivity; and c) increased pulmonary arterial pressure. There is also no doubt that sleeping in moderate altitude (2000-3000 m) as performed by the athletes using either live high-train high (LHTH) or live high-train low (LHTL) methods leads to periodic breathing, intermittent hypoxia (IH) and increase in desaturation periods; e.g. 3% oxygen desaturation index, but to a larger extent in hypobaric hypoxia (HH, real altitude) than in normobaric hypoxia (NH, simulated altitude), as shown at 2250 m (2). The three main questions debated in the present contrasting perspective are however different: 1. Are there any evidences showing if the “counteracting maladaptation” (reported above) outweigh the benefits of the different hypoxic methods at short- or long-term in elite athletes? ; 2. Are there any robust data supporting that hypoxic training is beneficial in elite athletes? ; 3. Contradictory, are there robust data showing that hypoxic training is not beneficial in elite athletes?

A COMPARISON OF RACE PERFORMANCE CHARACTERISTICS BETWEEN ELITE MALE 50-M AND 100-M FREESTYLE SWIMMERS BASED ON THEIR RESULTS

The aim of this research was to determine the differences in specific race performance characteristics of male swimmers in the 50-m and 100-m freestyle at the Serbia Open Championship 2017 (long-course). The overall sample included in this study consisted of 40 swimmers divided by a K-Means Cluster Analysis into three groups in relation to the results in the 50-m freestyle (G1_50, T50=23.53±.27 s, n=6; G2_50, T50=24.54±.33 s, n=18; G3_50, T50=25.52±.33 s, n=16), and 55 swimmers also divided into three groups in relation to the results in the 100-m freestyle (G1_100, T100=50.99±.82s, n=10; G2_100, T100=53.41±.48 s, n=17; G3_100, T100=56.13±1.32 s, n=28). The research results indicate that there is a difference in the specific race performance characteristics in relation to the achieved results in the 50-m freestyle, including: t10_50 (F=16.79, p=.000), SL2_50 (F=4.44, p=.019) and SI2_50 (F=13.49, p=.000), also in the 100-m freestyle, including: t10_100 (F=36.45, p=.000), SL1_100 (F=5.77, p=.005), SL2_100 (F=17.47, p=.000), SL3_100 (F=7.72, p=.001), SL4_100 (F=9.84, p=.000), SI1_100 (F=5.12, p=.009), SI2_100 (F=45.97, p=.000), SI3_100 (F=13.86, p=.000), SI4_100 (F=31.23, p=.000), SR1_100 (F=4.12, p=.022) and SR2_100 (F=6.37, p=.003). Based on these results we can draw the conclusion that swimmers who have better control over their race performance characteristics during all the segments of the race, including stroke length, stroke index and stroke rate have the potential of being faster in the 50-m and 100-m freestyle.

Beta alanine supplementation effects on metabolic contribution and swimming performance

BackgroundInvestigations of β-alanine supplementation shows effects on metabolic (aerobic and anaerobic) participation and performance on swimming by a possible blood acidosis buffering. Considering this background, the objective of the present study was to analyze the effects of β-alanine supplementation on metabolic contribution and performance during 400-m swim.MethodsThirteen competitive swimmers underwent a 6-week, double-blind placebo-controlled study, ingesting 4.8 g.day− 1 of β-alanine or placebo. Before and after the supplementation period, the total anaerobic contribution (TAn) and 30-s all-out tethered swimming effort (30TS) were assessed. Anaerobic alactic (AnAl) and lactic energy (AnLa) was assumed as the fast component of excess post-exercise oxygen consumption and net blood lactate accumulation during exercise (∆[La−]), respectively. Aerobic contribution (Aer) was determined by the difference between total energy demand and TAn. In addition to conventional statistical analysis (Repeated measures ANOVA; p > 0.05), a Bayesian repeated measures ANOVA was used to evidence the effect probability (BFincl).ResultsNo differences and effects were found between groups, indicating no supplementation effects. Repeated measures ANOVA, with confirmation of effect, was indicate reduce in ∆Lactate (p: 0.001; BFincl: 25.02); absolute AnLa (p: 0.002; BFincl: 12.61), fatigue index (p > 0.001; BFincl: 63.25) and total anaerobic participation (p: 0.008; BFincl: 4.89).ConclusionsThus, the results demonstrated that all changes presented were evidenced as a result of exposure to the training period and β-alanine supplementation doesn’t affect metabolic contribution and performance during 400-m freestyle.

The relationship between anthropometric characteristics and sports performance in national-level young swimmers

The main aim of this study was to verify associations between the anthropometric characteristics of young swimmers of different genders and different competitive levels with sports performance in 50m and 400m freestyle races at different levels (U-13 - Swimmers A and U-12 - Swimmers B). In addition, it was also intended to investigate the magnitude of the correlations between some specific variables (i.e., height, weight and wingspan) and the swimming performance. All participants were analyzed, regarding their anthropometric characteristics and their performance in the 50m and 400m freestyle swim. A total of 98 swimmers aged between 11-13 years old (mean ± standard deviation: 12.63 ± 0.76 years of age, 1.59 ± 0.08m height, 47.11 ± 7.82kg body weight) participated in the study. The results suggest that anthropometric characteristics have a positive relationship in the performance of swimmers when comparing genders (p&lt; 0,01), furthermore positive linear correlations was found in height (r = 0.305 and r = 0.253, p &lt;0.01), weight (r = 0.202 and r = 0.140, p &lt;0.01), and wingspan (r = 0.227 and r = 0.203, p &lt; 0.01) for 50m and 400m freestyle swim. The swimmers’ efficiency of segmental movements was related to anthropometric characteristics and strongly associated with the length of the swimmers’ segments. These results may be due to the fact that swimmers’ maturational status may have played an important role, in the observed results. In addition, when comparing genders, the height and weight values ​​of male swimmers tended to be higher. Furthermore, the differences observed in the 50m and 400m freestyle swimming events were related to the relationship that anthropometric characteristics have on the biomechanical parameters of swimming, which influence swimming performance. This study concluded that the improvement of performance of each young national-level swimmer is strongly related to the rate of growth, development and maturation.