Group Of Swimmers Research Articles

Does Higher Maturation Make Age-Grouped Swimmers Faster? A Study on Pubertal Female Swimmers

Background: The main aim of this study was to identify the differences between subgroups of swimmers based on physiological (peak oxygen uptake—VO2peak), strength (average tethered swimming force—60Fave), stroke kinematics (v100—swimming speed at 100 m front crawl, stroke rate—SR, stroke length—SL), and anthropometrical (i.e.,: biological age—BA, body height—BH, body mass—BM) factors within swimmers at different levels of maturity (BA). Methods: This study involved 39 female swimmers (age: 12.88 ± 0.54 years, BA: 13.98 ± 1.91 years). Cluster analysis (k-cluster) and stepwise multiple regression was performed. Results: Significant correlations were observed between v100 and BA, 60Fave, AS, VO2peak. Stepwise multiple regression indicated 60Fave and VO2peak as the main explanatory variables of v100 (R2 = 0.60, p < 0.0001). Cluster analysis allowed us to distinguish three groups of swimmers, differing in BA (cluster 1: 14.07 ± 0.96 years, cluster 2: 17.05 ± 1.53, cluster 3: 11.94 ± 0.95) and v100, as well as in BH, FFM, AS. Conclusions: There were differences between cluster groups, with early mature swimmers characterized by the highest BH, FFM, AS, 60Fave, and VO2peak. Probably, biologically younger late mature swimmers (cluster 3) are slower than the other 2 groups (cluster 1 and 2) because of being less somatically developed. Based on these study results, coaches should ensure further development of aerobic and anaerobic conditioning among normal mature swimmers with simultaneous focus on improving technique skills among early mature ones.

Mapping spatial patterns to energetic benefits in groups of flow-coupled swimmers.

The coordinated motion of animal groups through fluids is thought to reduce the cost of locomotion to individuals in the group. However, the connection between the spatial patterns observed in collectively moving animals and the energetic benefits at each position within the group remains unclear. To address this knowledge gap, we study the spontaneous emergence of cohesive formations in groups of fish, modeled as flapping foils, all heading in the same direction. We show in pairwise formations and with increasing group size that (1) in side-by-side arrangements, the reciprocal nature of flow coupling results in an equal distribution of energy requirements among all members, with reduction in cost of locomotion for swimmers flapping inphase but an increase in cost for swimmers flapping antiphase, and (2) in inline arrangements, flow coupling is non-reciprocal for all flapping phase, with energetic savings in favor of trailing swimmers, but only up to a finite number of swimmers, beyond which school cohesion and energetic benefits are lost at once. We explain these findings mechanistically and we provide efficient diagnostic tools for identifying locations in the wake of single and multiple swimmers that offer opportunities for hydrodynamic benefits to aspiring followers. Our results imply a connection between the resources generated by flow physics and social traits that influence greedy and cooperative group behavior.

Group cohesion and passive dynamics of a pair of inertial swimmers with three-dimensional hydrodynamic interactions

When swimming animals form cohesive groups, they can reap several benefits. Our understanding of collective animal motion has traditionally been driven by models based on phenomenological behavioral rules, but more recent work has highlighted the critical importance of hydrodynamic interactions among a group of inertial swimmers. To study how hydrodynamic interactions affect group cohesion, we develop a three-dimensional, inviscid, far-field model of a swimmer. In a group of two model swimmers, we observe several dynamical phases, including following, divergence, collision, and cohesion. Our results illustrate when cohesive groups can passively form through hydrodynamic interactions alone, and when other action is needed to maintain cohesion. We find that misalignment between swimmers makes passive cohesion less likely; nevertheless, it is possible for a cohesive group to form through passive hydrodynamic interactions alone. We also find that the geometry of swimmers critically affects the group dynamics due to its role in how swimmers sample the velocity gradient of the flow.

Limitations in Maximum Intensity Front Crawl in Swimmers with Down Syndrome

Individuals with Down Syndrome exhibit deficits in muscle strength and cardiovascular adaptation, which limit athletic performance. We compared a maximum-intensity 50 m front crawl test between competitive male swimmers with Down Syndrome (SDS; n = 11; 26.5 ± 5.6 years; m ± SD) and a control group of swimmers (CNT; n = 11; 27.1 ± 4.0 years) with similar training routines (about 5 h/week). Wearable sternal sensors measured their heart rate and 3D accelerometry. The regularity index Sample Entropy (SampEn) was calculated using the X component of acceleration. The total times (SDS: 58.91 ± 13.68 s; CNT: 32.55 ± 3.70 s) and stroke counts (SDS: 66.1 ± 9.6; CNT: 51.4 ± 7.4) were significantly higher in the SDS group (p < 0.01). The heart rate was lower in the SDS group during immediate (SDS: 129 ± 15 bpm; CNT: 172 ± 11 bpm) and delayed recovery (30 s, SDS: 104 ± 23 bpm; CNT: 145 ± 21 bpm; 60 s, SDS: 79 ± 27 bpm; CNT: 114 ± 27 bpm) (p < 0.01 for all the comparisons). The SampEn of sternal acceleration showed no differences between the groups and between 0–25 m and 25–50 m. Body pitch correlated strongly with performance in the SDSs (R2 = 0.632, p < 0.01), but during the first 25 m only. The high-intensity front crawl performances differed between the SDS and CNT athletes in terms of time, biomechanics, and training adaptation, suggesting the need for tailored training to improve swimming efficiency in SDSs.

Effect of regular winter swimming on blood morphological, rheological, and biochemical indicators and activity of antioxidant enzymes in males

BackgroundExposure of the human body to cold water triggers numerous beneficial physiological changes. The study aimed to assess the impact of regular winter swimming on blood morphological, rheological, and biochemical indicators and activity of antioxidant enzymes in males.MethodsThe study involved 10 male winter swimmers (the same participants examined before the season and after the season) and 13 males (not winter swimming, leading a sedentary lifestyle) in the control group. Fasting blood was collected twice: in November and in March of the following year. Basic blood morphological indicators, red cell elongation index (EI) and aggregation index (AI), concentrations of testosterone, cortisol, urea, and creatinine, as well as plasma activity of antioxidant enzymes of catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GPx) were determined.ResultsThe data were collected from the same winter swimmers at the beginning and end of the season. Winter swimming resulted in a significant increase of EI values at a shear stress of 0.30 (p = 0.40), 0.58 (p < 0.001), 4.24 (p = 0.021), 8.23 (p = 0.001), 15.59 (p = 0.001), 30.94 (p = 0.004), and 60.00 Pa (p = 0.043); haemoglobin was lower than before the season (p < 0.027). No significant changes were observed in AI, AMP, T1/2, the levels of urea, creatinine, eGFR, testosterone, cortisol, or the activity of CAT or SOD. There was a statistically significant increase in GPx activity (p = 0.014) and increase in testosterone concentration (p = 0.035) in the group of winter swimmers examined before the season as compared with the control group. No statistically significant differences were found for the mean values of blood morphological indicators and other parameters.ConclusionsWinter swimming can prove to be a health-promoting factor in males, as indicated by a rise in the deformability of red blood cells in the blood vessel system after a full season of winter swimming, leading to better body oxygenation, and improves the antioxidant defence and testosterone concentration (within standard limits) in the group of winter swimmers examined before the season as compared with the control group. Winter swimming helps maintain appropriate levels of blood rheological indicators, urea, creatinine, eGFR, cortisol, testosterone, and activity of antioxidant enzymes.Trial registrationClinicalTrials.gov identifier NCT06223087, 15.01.2024.

Countermovement-Jump and Pull-Up Performance Before and After a Swimming Race in Preparatory and Competitive Phases of a Swimming Season.

Monitoring performance athletes' training responses can be efficiently completed at competitive events. This study aimed to explore the changes in swimming, countermovement-jump (CMJ), and pull-up (PU) performance following training across a competitive phase, as well as immediately before and after each race. Fourteen well-trained male sprint/middle-distance swimmers (height 179 [7]cm, mass 70 [8]kg, age 18 [2]y), from 3 regional training groups, completed CMJ and PU tests before and after the national competitions in October and May, when race performance was also assessed. Swimming race performance was significantly improved from before the national competitions in October to after the national competitions in May (1.8% [3.2%], P = .044, d = 0.60, moderate effect). Although there were no significant changes in PU velocity, CMJ performance significantly improved from before the national competitions in October to after the national competitions in May (mean difference 2.29cm, P = .004, d = 3.52) and showed before-to-after race decreases (mean difference -1.64cm, P = .04, d = 2.28). Swimming performance and CMJ performance improved as the season progressed, although these improvements were not directly correlated. PU performance did not appear to be sensitive to training or race-induced fatigue, in contrast to CMJ, in this group of male swimmers.

Effect of schooling on flow generated sounds from carangiform swimmers

Computational models are used to examine the effect of schooling on flow generated noise from fish swimming using their caudal fins. We simulate the flow as well as the far-field hydrodynamic sound generated by the time-varying pressure loading on these carangiform swimmers. The effect of the number of swimmers in the school, the relative phase of fin flapping of the swimmers, and their spatial arrangement is examined. The simulations indicate that the phase of the fin flapping is a dominant factor in the total sound radiated into the far-field by a group of swimmers. For small schools, a suitable choice of relative phase between the swimmers can significantly reduce the overall intensity of the sound radiated to the far-field. The relative positioning of the swimmers is also shown to have an impact on the total radiated noise. For a larger school, even highly uncorrelated phases of fin movement between the swimmers in the school are very effective in significantly reducing the overall intensity of sound radiated into the far-field. The implications of these findings for fish ethology as well as the design and operation of bioinspired vehicles are discussed.

Correlation between scapular dyskinesia and core deficities in a group of competitive swimmers: an observational study

Background: The core and the shoulder are the focal points of the sporting gesture in swimming and their close connection allows the swimmer to express all his performance skills. For this reason, when one of these two components in dysfunctional, it can also compromise the other. Over the years, both the core and the shoulder have only been studied separately, so understanding their possible correlation is essential in order to improve not only the evaluation but also the treatment of these athletes. The aim of this study is to evaluate and analyze the presence of the correlation between scapular dyskinesia and core inefficiency in a group of swimmers. Methods: The athletes were evaluated through the use of test batteries developed through the analysis of scientific literature and through validated evaluation scales. The tests used concerned: the analysis of the scapular pattern, specific tests for scapular dyskinesia, differential evaluation tests with shoulder restrictions and impingement and core evaluation tests. Results: The athletes evaluated had a mean age of 16.93 at the time of data collection, with a range from 16 to 18 years. Ten athletes showed a type I scapular pattern; in fifteen they showed the presence of scapular dyskinesia while for the evaluation of the core in the majority they showed an inefficiency with chronometric times that are positioned below the average. No athlete showed positive differential tests for shoulder restraints and impingement. Conclusions: Data analysis showed that, in the group examined, there is indeed the presence of scapular dyskinesia and core inefficiency. The limit of this study concerns a possible generalization of the parameters sought, for this reason it would be useful in future research to investigate this correlation also in different swimming realities in order to be able to overcome this limitation and increase knowledge to improve both the functional evaluation and the subsequent treatment.

Prevalence of sunscreen use and sunburn in Greek athletes: a cross-sectional study.

Athletes participating in outdoor sports are in a high-risk category for prolonged sun exposure. This study investigates whether swimmers and beach volleyball athletes adopt appropriate measures to protect their skin from the sun. Sunscreens play a key role in protecting the skin from solar radiation and preventing premature aging. The study assesses the frequency of sunscreen use and the incidence of sunburn among athletes. Athletes completed a self-administered questionnaire regarding their sun protection and exposure habits. Participants aged 9 to 60 years, engaged in swimming (N.=1047) and beach volleyball (N.=785), were included in this study. In the group of swimmers (N.=858), a notable percentage never used sunscreen, and among those who did, (N.=137), natural products were predominantly applied. Gender differences revealed a significantly higher sunscreen usage (P<0.001) among female swimmers compared to males. Among beach volleyball athletes, sunscreen use was notably higher (90%), with 55.6% applying natural sunscreen and 44.4% opting for non-natural alternatives. Regarding the incidence of sunburn, the occurrence among both male and female swimmers was observed to be very low. Among those with sunburn, females exhibited a significantly higher frequency than males (P<0.001). Conversely, in beach volleyball athletes, sunburn affected a higher percentage of males (49.8%) than females (43.9%). Sunscreen utilization is notably insufficient among athletes, reflecting a limited awareness of the potential risks associated with sun exposure, even though they frequently suffer from sunburn. This heightened susceptibility places them at an increased risk of developing skin lesions. Initiating and disseminating awareness campaigns that specifically emphasize the importance of sunscreen use within the outdoor sports community is imperative.

Load-Velocity Profile and Active Drag in Young Female Swimmers: An Age-Group Comparison.

The present study aimed to establish differences in load-velocity profiling, active drag (AD), and drag coefficient (Cd) between 3 age groups of female swimmers. Thirty-three swimmers (11, 13, or 16y old) were recruited. The individual load-velocity profile was determined for the 4 competitive swimming strokes. The maximal velocity (V0), maximal load (L0), L0 normalized to the body mass, AD, and Cd were compared between the groups. A 2-way analysis of variance and correlation analysis were conducted. Compared with their younger counterparts, 16-year-old swimmers generally had larger V0, L0, and AD, which was particularly evident when comparing them with 11-year-old swimmers (P ≤ .052). The exception was breaststroke, where no differences were observed in L0 and AD and Cd was smaller in the 16-year-old group than the 11-year-old group (P = .03). There was a negative correlation between Cd and V0 for all groups in backstroke (P ≤ .038) and for the 11-year-old group and 13-year-old group in breaststroke (P ≤ .022) and front crawl (P ≤ .010). For the 16-year-old group, large correlations with V0 were observed for L0, L0 normalized to the body mass, and AD (P ≤ .010) in breaststroke and for L0 and AD with V0 in front crawl (P ≤ .042). In butterfly, large negative correlations with V0 were observed in the 13-year-old group for all parameters (P ≤ .027). Greater propulsive force is likely the factor that differentiates the oldest age group from the younger groups, except for breaststroke, where a lower Cd (implying a better technique) is evident in the oldest group.

Far-field hydrodynamic interaction in a group of swimmers

Three-dimensional schools of hydrodynamically axisymmetric swimmers self-propelling at a constant velocity are studied. We introduce a low-order model for the induced velocity based on the far-field approximation. We inquire if, by holding suitable relative positions in the three-dimensional space, the swimmers can reduce the overall energy consumption of the school in comparison with the same number of isolated individuals at the same velocity. We find a considerable (several per cent) energy saving achievable by chain formations. The benefit increases asymptotically with the number of individuals, towards a finite limit that is a function of the minimum allowed spacing between each pair of neighbours.

Oxygen uptake kinetics and biological age in relation to pulling force and 400-m front crawl performance in young swimmers.

Background: The study aimed to assess differences in the biological age (BA) of 13-year-old swimmers and show their ability, as biologically younger-late mature or older-early mature, to develop fast 60-s oxygen uptake () kinetics and tethered swimming strength. Furthermore, the interplay between swimming strength, , and 400-m front crawl race performance was examined. Methods: The study involved 36 competitive young male swimmers (metrical age: 12.9 ± 0.56years). Depending on BA examination, the group was divided into early-mature (BA: 15.8 ± 1.18years, n = 13) and late-mature (BA: 12.9 ± 0.60 years, n = 23) participants, especially for the purpose of comparing tethered swimming indices, i.e., average values of force (F ave) and (breath-by-breath analysis) kinetic indices, measured simultaneously in 1-min tethered front crawl swimming. From the 400-m racing stroke rate, stroke length kinematics was retrieved. Results: In the 1-min tethered front crawl test, early-mature swimmers obtained higher results of absolute values of and F ave. Conversely, when was present relatively to body mass and pulling force (in ml∙min-1∙kg-1∙N-1), late-mature swimmers showed higher relative usage. Late-mature swimmers generally exhibited a slower increase in during the first 30s of 60s. , F ave, BA, and basic swimming kinematic stroke length were significantly interrelated and influenced 400-m swimming performance. Conclusion: The 1-min tethered swimming test revealed significant differences in the homogeneous calendar age/heterogeneous BA group of swimmers. These were distinguished by the higher level of kinetics and pulling force in early-mature individuals and lower efficiency per unit of body mass per unit of force aerobic system in late-mature peers. The higher kinetics and tethered swimming force were further translated into 400-m front crawl speed and stroke length kinematics.

The effect of swimming on the body posture, range of motion and musculoskeletal pain in elite para and able-bodied swimmers

BackgroundElite swimmers may be predisposed to disturbances in the range of motion (ROM) of hip joints and spinal curvatures, which are a factor that induces body’s compensatory mechanisms that may have an impact on sports training, athletic performance and health. This study aimed to identify compensatory mechanisms in body posture of elite Para and able-bodied swimmers (spinal curvatures, ROM), to indicate the dominant locations of the compensatory mechanisms in the groups of Para and able-bodied athletes, and to identify and compare the prevalence and location of musculoskeletal pain from the last week and the last six months in the context of compensatory mechanisms.MethodsThirty-five (nF = 8; nM = 27; age = 20.51 ± 4.24) elite Para and able-bodied swimmers from the Polish national team took part in the study and were divided into: study group (SG) of Para swimmers and control group (CG) of able-bodied swimmers. Depth of the anteroposterior spinal curvatures and sagittal spinal mobility testing were evaluated with a Medi Mouse device. The prevalence and locations of musculoskeletal pain were assessed with a Nordic Musculoskeletal Questionnaire for the last seven days (NMQ-7) and the last six months (NMQ-6).ResultsIn both groups lumbar hypolordosis, anterior pelvic tilt and pain in the shoulders, lower back and hips/thighs (NMQ-7) were reported the most frequent. In SG several significant relationships were found between duration of sport-specific training experience (years) and depth of angle the lumbar lordosis, the depth of the angle of pelvic inclination the ROM in the lumbar spine and thoracic spine, what was not reported in CG.ConclusionsExtrinsic compensatory mechanism was identified in both study groups, however only in SG it occurred as structural (depth of the angle of lumbar lordosis and pelvic inclination) and functional changes (ROM in the thoracic and lumbar spine) in the body posture. Internal compensatory mechanism was identified in SG, however external compensation showed only partially suppressive character regarding to internal compensation. The locations of the musculoskeletal complaints seems to result from both internal compensatory mechanism (SG) and continuous overload of the anatomy trains as a result of swimming training (SG, CG).

Pacing Strategy of 800 m and 1500 m Freestyle Swimming Finals in the World Championships According to the Performance in Males and Females of Different Age Groups

Pacing strategy refers to the distribution of effort and speed throughout the race to achieve optimal performance. This study aims to understand whether the choice of pacing strategy in swimming depends on the length of competitions and how sex, age, and performance level influence this strategy. Participants were the finalists of the 800 m and 1500 m freestyle events at the elite and junior world championships in 2022–2023. Race outcomes and pacing parameters were compared between the two distances and across different groups of swimmers. Swimmers in both distances did not break world records. Pacing strategy generally followed a U-shape with significant differences in the frequency and duration of speed changes between the two distances. The 800 m exhibited more frequent changes in acceleration, while the 1500 m events generally followed a more consistent time-series pattern. There were differences in pacing strategies between males and females and between junior and elite swimmers. Swimmers closer to world records showed more consistent pacing patterns compared to those farther from records. This study suggests that pacing strategies are influenced by race distance, sex, age, and performance level. The research highlights the complex interplay between physiological and psychological factors that shape a swimmer’s decision-making during a race.

Effect of self-modeling and self-controlled feedback on the performance of professional swimmers and waterpolo players

Self-modeling (SM) and self-control (SC) feedback can be presented as two solutions for learning improvement. Therefore, the aim of the present study was to investigate the effects of SM and SC feedback on 100-m freestyle performance of professional swimmers and waterpolo players. 25 elite male swimmers and waterpolo players, were randomly assigned to four groups: swimmer group with SM, swimmer group with SM and SC feedback, waterpolo players group with SM, and waterpolo players group with SM and SC feedback. 100-m freestyle times and performance were recorded. SM and SC feedback for the participants were utilized at the acquisition stage. The device used included a Lenovo B570 laptop and an Exilim ZR200 canon camcorder. SM and SC feedback presented to the swimmers and waterpolo players led to improved speed and results, and the effect of presenting SM with SC feedback to swimmers had better results. In conclusion, the present study indicates that SC modeling of watching video is a suitable method for professional swimmers. Water polo trainers can also use SM and SC feedback to enhance their players' swimming technique.

The kinematic profile of ventral swimming start: sex diversity.

It has been suggested that sex distinctions in physiology may affect the swimming performance of each sex differently. Yet, sex-based performance dependency has not been taken into consideration by most of the researchers evaluating swimming start. Therefore, the purpose of this research was to determine the effect of sex heterogeneity on the spatiotemporal characteristics of swimming start by investigating the determinants of its performance. A total of fifty-two international-level swimmers (thirty females and twenty-two males) performed three repetitions of the kick-start up to the 15-m mark. During trials, data were collected using video cameras and instrumented starting block. To search for evidence of differences between the two groups, the one-way ANOVA was conducted. Pearson's correlation coefficients were calculated between measurements widely used to describe overall starting performance and selected kinematical variables of swimming start. A sex effect was exposed for temporal variables describing all swimming start phases (p ≤ 0.015). Male swimmers, by spending less time during the push-off from the starting block (p = 0.002; η p 2 = 0.18), reaching higher take-off velocity (p < 0.001; η p 2 = 0.29), traveling longer distances during flight (p < 0.001; η p 2 = 0.40), and swimming faster in the water phase (p < 0.001; η p 2 = 0.40), took starting advantage over their female counterparts. Consequently, performance measures such as 5-m, 10-m, and 15-m start times indicated that male participants were faster than females (p < 0.001; η p 2 ≥ 0.40). Only in the group of male swimmers a significant correlation between variables describing overall starting performance (5-m, 10-m, and 15-m times), and variables commonly highlighted as starting performance determining factors (block phase duration, take-off horizontal velocity, and flight distance) was found. The current study shows that the spatiotemporal variables of swimming start, the relation between them as well as overall starting performance, vary by sex. Consequently, the requirement of sex factor and its heterogeneity effect should be included not only in detailed characteristics of separate variables but also in all approaches undertaken. Those findings seem to play a crucial role mainly in swimming start evaluations in post-pubertal age groups of swimmers.

Pulmonary Function Test: Relationship Between Adolescent Swimmers and Finswimmers.

The aim of our study was to investigate the effects of training on the static and dynamic respiratory parameters in adolescent female swimmers (SWs) and finswimmers (FSWs). Forty-six female adolescent SWs (n=24, age=17.6±0.7 years) and FSWs (n=22, age=17.0±1.2 years) volunteered for this study. All participants underwent standard spirometry and lung volume measurements and were collected anthropometrical and morphological characteristics. The results of the groups in the pulmonary function test parameters, namely, inspiratory capacity (IC), expiratory reserve volume (ERV), and peak expiratory flow (PEF), were significantly different. Higher values of IC, ERV, and PEF were observed in the FSW group than the SW group: IC = 116.5±13.2 (SWs) vs. 125.5±11.5 (FSWs) % of predicted, p = 0.019; ERV = 121.8±14.8 (SWs) vs. 130.6±12.5 (FSWs) % of predicted, p = 0.036; PEF = 111.6±7.5 (SWs) vs. 116.3±5.0 (FSWs) % of predicted, p = 0.018. The differences between groups probably reflect the activation of different muscle groups.

The Effects of 6-Week Training Cessation on Anthropometrics, in-Water Force, Performance, and Kinematics of Young Competitive Swimmers: A Maturity Development Approach.

To examine the effects of 6weeks of training cessation on young swimmers' anthropometrics, in-water force, performance, and kinematics according to biological maturation. Eighteen swimmers (7 girls: 12.43 [0.73] y old; 11 boys: 13.27 [0.79] y old) were assessed pretest and posttest 6weeks apart. Body mass, stature, arm span, and hand surface area were measured as anthropometric parameters, and biological maturation was estimated (ie,peak height velocity [PHV]). The in-water force was retrieved during 2 bouts of 25-m front crawl, allowing the estimation of the symmetry index. The time to complete the 25-m was considered the performance outcome, whereas velocity, stroke rate, stroke length, stroke index, and arm stroke efficiency were used as kinematic parameters. All anthropometric parameters increased during the detraining period. Although the in-water force remained unchanged, the magnitude of the effects was large for the symmetry index (P = .021; d = 0.87). For the pooled sample, neither performance nor kinematics changed after detraining, but the stroke index increased (P = .054; d = 0.27). Pre-PHV swimmers showed unchanged values in all parameters, despite natural growth. Mid-PHV swimmers showed a similar trend in addition to reductions in stroke rate (P = .040; d = 0.60) and increases in stroke length (P = .043; d = 1.00). In-water force, performance, and kinematics (25-m front crawl) were not impaired after 6weeks of training cessation in a group of young swimmers. Given interindividual and intraindividual differences according to maturity status, coaches should be aware that distinct trends within the group can be found.

Performance Tiers within a Competitive Age Group of Young Swimmers Are Characterized by Different Kinetic and Kinematic Behaviors.

The present study aimed to analyze swimmers' in-water kinetic and kinematic behaviors according to different swimming performance tiers within the same age group. An amount of 53 highly trained swimmers (girls and boys: 12.40 ± 0.74 years) were split up into 3 tiers based on their personal best performance (i.e., speed) in the 50 m freestyle event (short-course): lower-tier (1.25 ± 0.08 m·s-1); mid-tier (1.45 ± 0.04 m·s-1); and top-tier (1.60 ± 0.04 m·s-1). The in-water mean peak force was measured during a maximum bout of 25 m front crawl using a differential pressure sensors system (Aquanex system, Swimming Technology Research, Richmond, VA, USA) and defined as a kinetic variable, while speed, stroke rate, stroke length, and stroke index were retrieved and considered as kinematic measures. The top-tier swimmers were taller with a longer arm span and hand surface areas than the low-tier, but similar to the mid-tier. While the mean peak force, speed and efficiency differed among tiers, the stroke rate and stroke length showed mixed findings. Coaches should be aware that young swimmers belonging to the same age group may deliver different performance outcomes due to different kinetic and kinematic behaviors.

Rapid Change in the Direction of Hand Movement to Increase Hand Propulsion During Front Crawl Swimming.

This study aims to investigate the difference in hand acceleration induced by rapid changes in hand movement directions and propulsion between fast and slow groups of swimmers during front crawl swimming. Twenty-two participants, consisting of 11 fast and 11 slow swimmers, performed front crawl swimming at their maximal effort. Hand acceleration and velocity and the angle of attack were measured using a motion capture system. The dynamic pressure approach was used to estimate hand propulsion. In the insweep phase, the fast group attained significantly higher hand acceleration than the slow group in the lateral and vertical directions (15.31 [3.44]m·s-2 vs 12.23 [2.60]m·s-2 and 14.37 [1.70]m·s-2 vs 12.15 [1.21]m·s-2), and the fast group exerted significantly larger hand propulsion than the slow group (53 [5]N vs 44 [7]N). Although the fast group attained large hand acceleration and propulsion during the insweep phase, the hand velocity and the angle of attack were not significantly different in the 2 groups. The rapid change in hand movement direction could be considered in the technique of underwater arm stroke, particularly in the vertical direction, to increase hand propulsion during front crawl swimming.