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Producción científica derivada específicamente del proyecto Swim3 (PID2022-142147NB-I00). Las contribuciones de los miembros del laboratorio no vinculadas al proyecto se recogen en Publicaciones · AquaticsLab.
Publicaciones del proyecto Swim3
Producción científica derivada específicamente del proyecto PID2022-142147NB-I00. Cita en formato APA 7. El abstract de cada artículo se reproduce tras la referencia DOI.
This study examined the acute effects of combining short-duration static stretching with resistance-based activation, designed to induce post-activation performance enhancement (PAPE), on upper-limb muscle mechanics and neuromuscular performance. Fourteen competitive swimmers (7 male, 7 female) completed three randomized warm-up protocols: (1) general aerobic activity (CON), (2) Aerobic activity + 2 × 30 s of static stretching for latissimus dorsi and pectoralis major (SS), and (3) Aerobic activity + static stretching + 3 × 5 reps of resistance-band pull-overs (SS/PAPE). Shoulder extension range of motion (ROM), pectoralis- and latissimus dorsi-passive muscle stiffness and elasticity as well as isometric/dynamic torque, rate of force development (RFD), and power (isokinetic dynamometer) were assessed pre- and 10 min post-intervention. Results showed significant Time × Protocol interactions for ROM, maximal torque, RFD, and average torque. SS/PAPE elicited the largest ROM gain and improvements in dynamic performance, with significant increases in average torque and RFD, while SS led to modest ROM increases but small and non-significant declines in average torque and RFD. Passive muscle stiffness and elasticity exhibited non-significant changes in all groups. Although relative changes were comparable across sexes, males consistently outperformed females in torque and RFD, while females presented higher ROM than males. These findings demonstrate that integrating brief static stretching with sport-specific, high-intensity upper-limb activation can acutely enhance flexibility and explosive force generation without impairing performance. The Stretching + PAPE approach offers a practical, time-efficient warm-up strategy for overhead athletes, particularly in contexts where rapid force production at extended joint positions is essential.
Plyometric training has been proposed as a relevant tool for swimming performance, especially in turns, given its biomechanical similarity to the push-off phase. This study aimed 1) to analyse the relationship between the drop jump (DJ) variables and the tumble turn variables and 2) to explore which DJ variables may predict the tumble turn time. A cross-sectional design was used to examine the relationship between the DJ and tumble turn performance. Eighteen swimmers (9 females, 14.3 ± 0.8 years; and 9 males, 15.2 ± 0.5 years) participated. Swimmers completed a standardized dryland warm-up followed by 5 sets of a single DJ. Subsequently, participants underwent a standardized in-water warm-up before performing 3 front crawl tumble turns. Sex-stratified correlations, exploratory linear stepwise multiple regression, and network analyses were performed to examine the relationships between DJ variables and tumble turn performance. Jump height correlated with the mean horizontal velocity during the wall contact active phase for females (r = 0.71; p = 0.033) and males (rho=0.9; p = 0.001). The tuck index of the DJ (TI G ) showed association with the time from wall contact to 2.5 m (T2.5m-out) for females (r = 0.76; p = 0.018) and males (r = -0.67; p = 0.047). Exploratory multiple regressions explained the T2.5m-out for females and males (87% and 88% of the variance, respectively) with TI G as the main predictor in both. In conclusion, DJ performance was associated with tumble turn performance. Variations in the tuck index during DJ, reflecting different hip and knee displacement patterns, may be linked to differences in tumble turn efficiency.
For more than half a century, swimming resisted scientific analysis. When Leon Lewillie opened the first International Symposium on Biomechanics and Medicine in Swimming in Brussels in 1970, he identified the obstacle precisely: a barrier of water had isolated our sport from rigorous measurement. This lecture explores how this barrier became permeable. Starting with Lewillie's balloon-borne electromyograms, it follows the development through Jan Pieter Clarys's five decades of towing-tank and muscle work, which demonstrated that technique rather than body form governs resistance, and on to my own nine editions of this symposium, where the focus shifted from developing instruments to understanding the properties of water itself. The second half turns to the force now reshaping the field: artificial intelligence. Computer vision can already segment races and measure the underwater dolphin kick, while wearable sensors can classify strokes and explainable models can rank the variables behind performance and flag injury risk before it occurs. However, these tools can produce inaccurate results, hide their reasoning and have not read much of our literature. The argument is simple yet demanding: machine learning provides scale and speed, while fluid mechanics provides cause. Only their collaboration — with the scientist firmly in the loop — yields understanding. Fifty-six years after Lewillie, the water still resists; the machine is powerful, yet blind; and the researcher must still ask the right questions and stand by the answers.
BACKGROUND: Swimming biomechanics still explains propulsion as the hands and feet 'pushing water backwards'. However, years of flow visualisation have revealed a different story. During a cycle, the hand does not propel the body by pushing a compact mass of water. Instead, it continuously modifies the surrounding flow, creating pressure gradients, fluid accelerations and vortical structures. These evolving flow structures redistribute momentum and mechanical energy throughout the surrounding water. Consequently, the hydrodynamic force measured at a particular instant only represents one aspect of the interaction. A complete physical description must also account for the transient storage, convective transport, and dissipation of mechanical energy within the flow field generated by the swimmer. We therefore describe human aquatic propulsion as an energy–momentum continuum, and argue that the force-based and continuum concepts are complementary rather than competing. METHODS: In a conceptual, conference-length format, the case is built in three linked steps — 'Bridging the Gap', 'Decoding the Mechanics of Speed', and 'Beyond Force' — explained in an illustration in each case. The reasoning rests on the Navier–Stokes equations, on global energy and momentum balances, on a Helmholtz decomposition of the flow, and on a BIV–CFD validation chain; derivations are kept to a minimum. RESULTS: The framework redefines the single force value per cycle in terms of power flow (in watts), energy turnover per cycle, momentum transfer and work cycles. It explains why the Strouhal number determines which mechanism dominates in each body segment, yielding quantities that can be used by coaches and equipment designers. CONCLUSIONS: 'Beyond force' means thinking past it by putting energy, momentum and vortices at the centre, while keeping what kinematics has already taught us.
The use of programming tools in swimming biomechanical analysis has become increasingly relevant due to the need for accessible cost-effective, and accurate evaluation methods. These tools allow coaches, swimmers, and technical staff to perform detailed underwater analyses without relying on expensive or complex systems. Therefore, the aim of this study was to develop a methodological protocol for analyzing front-crawl biomechanics using programming tools and specialized software such as Kwon3D and MATLAB. Three female student swimmers from the Faculty of Sport Sciences at the University of Granada (22±1 years, 1.66±0.03 m of height, 61.17±3.21 kg of body mass, 31.5±1.1 s 50 m front-crawl time) voluntarily participated in a resisted swimming test. Each swimmer completed 20 m trials under four loading conditions (0, 1, 3, and 5 kg) applied using the 1080 Sprint 2. Data were collected in a 5×2 m underwater recording area starting at the 10 m line. Four GoPro HERO9 cameras were used for motion capture. A right wrist-mounted tracker was attached to each participant to facilitate motion tracking. Movement data were processed using Kwon3D software to extract 3D coordinates (X, Y, and Z axes). Subsequently, a custom MATLAB script was developed to analyze the data, compute average trajectory curves for each axis, and compare the unloaded condition with the resisted conditions. As a result, the average trajectories were calculated across the three swimmers for each axis and load condition. A margin of ±0.05% of the maximum and minimum values was registered along the trajectories. The developed protocol through the integration of programming tools enabled a systematic analysis of front-crawl biomechanics using Kwon3D and MATLAB, facilitating efficient data processing and contributing to a better understanding of the kinematic changes that occur during semi-tethered swimming. Future studies should include larger sample sizes and compare a wider range of loading conditions to further validate and expand these findings.
BACKGROUND: Load-velocity profiling (LVP) using semi-tethered devices is a validated methodology for quantifying force and velocity capabilities in surface swimming, yet its application to underwater undulatory swimming (UUS) remains unexplored. This study aimed to characterize the LV profile during UUS, investigate the relationship between the LV profile and UUS performance and anthropometrics, and examine sex-based differences. METHODS: Thirty-three competitive swimmers (21 males, 12 females) performed a LV profile test. Individual LV profiles were constructed via linear regression of each trial and the theoretical maximum velocity (V0), the theoretical maximum load (L0), and the slope of the regression line (Slope) were calculated. Anthropometric measurements included height, arm span, body mass, sitting height, body length, biacromial and biiliocristal breadths, and derived indices. RESULTS: High linearity was confirmed for the LV profile (R² = 0.987 ± 0.015, males; 0.981 ± 0.023, females). Except for Slope in males, the LV profile-derived variables were largely to nearly perfectly correlated with UUS performance in both sexes (p<0.05). Body mass showed moderate association with L0 (r = 0.39) and Slope (r = 0.42) in males and no other significant association between anthropometrics and performance was observed (p>0.05). Males exhibited higher V₀ (1.58 ± 0.17 vs. 1.39 ± 0.14 m·s⁻¹, p<0.01) and L₀ (7.99 ± 2.38 vs. 5.76 ± 1.02 kg, p<0.01). Females showed steeper load-velocity Slopes (–0.21 ± 0.05 vs. –0.25 ± 0.03, p<0.05). CONCLUSIONS: LV profile methodology is applicable to UUS assessment, with limited direct influence of anthropometric factors and clear differences between sexes.
BACKGROUND: Wearable inertial sensors are increasingly used to monitor swimming performance; however, evidence regarding their validity remains limited and inconsistent, particularly in Para swimmers, whose alterations in coordination, symmetry and propulsion may challenge head-mounted inertial event detection. This study aimed to provide a preliminary evaluation of the validity and agreement of the Triton 2 Unit system (triaxial accelerometer, gyroscope and magnetometer) against video-based analysis in swimmers with and without disabilities. METHODS: Four male and two female competitive swimmers (three without disabilities and three Paralympic swimmers) performed a structured training protocol under controlled conditions. Performance metrics derived from the head-worn inertial sensor were compared with a video-based reference. Variables analysed included lap time, mean stroke rate, number of strokes, underwater time, and turn time. Agreement and accuracy were assessed using median bias, interquartile range (IQR), median absolute percentage error (MdAPE), Lin's concordance correlation coefficient (ρc), and non-parametric 95% limits of agreement. RESULTS: In swimmers without disabilities, Triton showed high agreement for lap time (ρc = 0.968), stroke rate (ρc = 0.962), and number of strokes (ρc = 0.955), with low relative errors. Moderate agreement was observed for underwater time (ρc = 0.829), while turn time showed poor agreement (ρc = 0.228). In Para swimmers, agreement was generally lower and more variable, with wider limits of agreement across all variables. Lap time (ρc = 0.869) and stroke rate (ρc = 0.822) showed the highest consistency, whereas underwater time, number of strokes, and turn time showed reduced agreement. In one swimmer with severe impairment (S5), the device failed to correctly identify lap structure, leading to invalid outputs. CONCLUSIONS: Triton 2 Unit provides acceptable accuracy for selected metrics in swimmers without disabilities under ecological conditions. In Para swimmers, increased variability and occasional detection failures limit its applicability, particularly for event-based variables and severe impairments.
Purpose : Despite the growing global prominence of elite open-water (OW) swimming, little is known about how seasonal variation influences the physiological and kinematic determinants of maximal performance. This study aimed (1) to evaluate the seasonal changes in performance, physiological, and kinematic factors in maximal incremental swimming tests in elite OW swimmers and (2) to examine the influence of physiological and kinematic factors on the maximal swimming performance. Methods : Eighteen world-class and elite (12 males [25.4 (3.3 y)] and 6 females [26.4 (3.9) y]) OW swimmers voluntarily participated. A total of 57 (40 male and 17 female) intermittent incremental tests (7 × 400 m) in a 50-m pool were analyzed at 4 different moments (October 2022, February and October 2023 and March 2024). Heart rate; blood lactate concentration ([La − ]); aerobic (AeT) and lactate thresholds (LT); swimming speed; and stroke rate, length, and index were assessed. Results : The OW swimmers showed no changes in performance or physiological factors between tests. In males, the stroke length and index changed in both AeT and LT, whereas no kinematic changes were observed in females. The maximum swimming speed was positively associated with speed at AeT and LT in both sexes, while only males showed association between [La − ] at LT. Stroke length and index at AeT and LT in males and stroke rate at AeT and LT were positively associated with maximum swimming speed. Conclusions : Despite stable performance and physiological factors, seasonal changes in stroke technique highlight the importance of monitoring kinematics to guide training or competition of elite swimmers.
ABSTRACT This study aimed to determine elite swimmers’ pacing strategy in the 3000 m event and to analyse the associated performance variability and pacing factors. Forty-seven races were performed by 17 male and 13 female elite swimmers in a 25 m pool (20.7 ± 2.9 years; 807 ± 54 FINA points). Lap performance, clean swim velocity (CSV), water break time (WBT), water break distance (WBD), stroke rate (SR), stroke length (SL) and stroke index (SI) were analysed including and excluding the first (0–50 m) and last lap (2950–3000 m). The most common pacing strategy adopted was parabolic. Lap performance and CSV were faster in the first half of the race compared to the second half (p < 0.001). WBT, WBD, SL and SI were reduced (p < 0.05) in the second half compared to the first half of the 3000 m when including and excluding the first and last laps for both sexes. SR increased in the second half of the men’s race when the first and last laps were excluded. All studied variables showed significant variation between the two halves of the 3000 m, the highest variation being obtained in WBT and WBD, suggesting that fatigue negatively affected swimming kinematics.
Purpose: The assessment of lactate threshold (LT) and its relationship to open-water (OW) performance is crucial. This study aimed (1) to analyze LT in world-class OW swimmers, (2) to compare swimming speed at LT (SSLT) and 4 mmol·L−1 of blood lactate concentration ([La−]; SS4), and (3) to examine the relationships between SSLT and swimming performance. Methods: Twenty world-class and elite (11 male, 26.4 [3.0] y; 9 female, 25.8 [3.6] y) OW swimmers voluntarily participated. A total of 46 (29 male and 17 female) intermittent incremental tests (7 × 400 m) conducted in a 50-m pool were analyzed. Seasonal best performances on 400-, 800-, and 1500-m and 10-km OW swimming events were obtained. Results: The SSLT was 1.62 (0.02) (3.8 [1.0] mmol·L−1) and 1.46 (0.04) m·s−1 (3.0 [0.7] mmol·L−1) in males and females, respectively, which corresponded to 97% of the peak speed reached in the tests. There were no differences (P = .148) between SSLT and SS4 in males; however, SSLT was lower (P = .019) than SS4 in females. The SSLT was negatively correlated with swimming performance, with the exception of 10-km OW and 400-m times in males and females, respectively. Conclusions: World-class and elite OW swimmers exhibited a greatly developed aerobic capacity with LT close to their maximum speed. The SS4 could be used as an approximation to SSLT in males but overestimates true aerobic capacity in females. LT is a useful tool for assessing performance, as OW swimmers with higher SSLT showed better swimming performance.
AbstractThis study aimed to investigate the relationship between the load–velocity profile and sprint swimming performance and kinematics, explore the inter-relationships of the load–velocity profile variables and blood lactate concentrations [La−] and dry-land strength (pull-ups), and examine sex-based differences. Twenty-seven swimmers (15 males: 19.2±3.7 y; 50 m front-crawl 550±70 World Aquatics points; 12 females: 17.7±2.4 y; 50 m front-crawl 552±63 World Aquatics points) underwent a 50 m front-crawl all-out swim test, a load–velocity profile test, and a pull-up test. Theoretical maximum velocity was associated with sprint swimming performance (r>0.863 and p<0.001), but not the theoretical maximum load (L 0) or the slope (p>0.05) for both sexes. An association between kinematics during the load–velocity profile test and free swimming was weakened as the load increased, with the correlation coefficient (r) decreasing from 0.929 to 0.403. Theoretical maximum velocity and theoretical maximum load were primarily associated with both sexes with the first (r>0.950 and p<0.001) and last (r>0.849 and p<0.001) semi-tethered trials, respectively. Only in females [La−] was associated with the theoretical maximum load and slope (r>0.573 and p<0.05). Males exhibited greater values than females in all the assessed variables (p<0.05) except for stroke rates and [La−]. The load–velocity profile is a valuable tool for assessing performance in both sexes. Kinematic parameters were related between semi-tethered and free swimming; however, association diminished with increasing load.
Abstract Background Swimming performance depends on a wide variety of factors; however, the interaction between these factors and their importance varies between events. In sprint events, the characterized pacing underlines its specific development, as swimmers must achieve the highest possible speed while sustaining it to the greatest extent possible. Objectives The aim of this review was to identify the key factors underlying sprint swimming performance and to provide in-depth and practical evidence-based information to optimize performance. Methods The review protocol was not registered. PubMed, Web of Science and Scopus databases were searched up to October 31, 2023. Studies involving competitive swimmers and investigating sprint swimming performance were included, while studies conducted with young or masters’ swimmers, triathletes or waterpolo players or not investigating sprint swimming performance were excluded. The Downs and Black Quality Assessment Checklist was performed on the included articles to assess the methodological quality. Results After applying the PICOS framework, 39 of the 1330 articles initially identified were included according to the PRISMA guidelines. The included records focused mainly on dry-land strength and in-water forces of both upper and lower limbs. A wide range of kinematic variables were also examined, together with the importance of anthropometric and various physiological parameters. Conclusion This review highlights the importance of developing muscular strength and effectively transferring it to performance in the water. The evidence suggests that muscular development should prioritize enhancing velocity and effective displacement, rather than merely increasing force and performance in loaded tests. However, further research is needed to confirm this. While in-water forces have been well studied, there is a notable lack of analysis regarding drag. The optimal balance between stroke rate and stroke length should be determined individually, with a primary focus on achieving a high stroke length from a high stroke rate. Although anthropometry may play an important role in performance, the interaction of these traits appears to be complex, suggesting that other factors may be more important in determining performance outcomes. From a physiological perspective, the results indicate that the lactate peak and rate of accumulation should be thoroughly developed. Notwithstanding, this review shows the lack of a solid body of knowledge on the importance of anaerobic and especially aerobic factors. Finally, the absence of a list of potential confounders, together with the lack of high-quality studies involving elite swimmers (level 1 and 2), complicates the interpretation of the results.
Purpose: To assess the effect of 5-week training-cessation period on performance and load–velocity profile-related variables. Methods: Twenty-four competitive swimmers (15 male and 9 female: 19.2 [3.7] and 17.3 [2.3] y, 50-m front-crawl 550 [70], and 572 [51] World Aquatics points, respectively) performed a 50-m front-crawl all-out swim, a load–velocity profile, and a pull-up test before and after a 5-week off-season period. Kinematic variables, blood lactate concentration, and rating of perceived exertion were monitored during the load–velocity profile tests. Results: Performance was impaired 1.3% for males (P < .01) and 3.8% for females (P < .01). Neither anthropometric changes (males r2 = .277, females r2 = .218, P > .05) nor the physical activity performed during the off-season (males r2 = .329, females r2 = .094, P > .05) attenuated performance impairments. While males counteracted the stroke-rate decline (P < .05) by increasing stroke length (P < .05) in the majority of the race, females did not, leading to a decline in clean swimming speed (P < .05). The maximum load at zero velocity decreased (P < .05) during the load–velocity profile test. In addition, males showed an increased blood lactate concentration (P < .05), whereas females decreased the maximum velocity at zero load (P < .01) and stroke rate (P < .01). No change in the slope was observed for either sex (P > .05). Conclusion: Following a 5-week off-season period, sprint swimming performance declines (males 0.34 s; females 1.15 s). The load–velocity profile and related variables evidenced deterioration, showing changes in blood lactate concentration, maximum load at zero velocity, average velocity during the third trial, and stroke rate.
ABSTRACTChildren and adults may react differently to warm‐up preservation due to different physical characteristics. This study aimed to: (i) assess the impact of different rewarm‐up routines in swimmers during a transition phase (20–25 min), including passive rest (SWU) or dynamic activities (RWU), on countermovement jump and swimming start performances, and (ii) explore potential RWU adaptations considering maturity offset (peak height velocity—PHV) and sex. Performance was analyzed using mixed effect ANCOVA, considering protocol, maturity offset (pre‐PHV, mid‐PHV, post‐PHV, and adv. post‐PHV), and sex. Results favored RWU over SWU with substantial magnitudes for jump height: pre‐PHV (min‐20, ES = 1.21; min‐25, ES = 1.65), mid‐PHV (min‐20, ES = 1.23; min‐25, ES = 1.14), post‐PHV (min‐20, ES = 1.37; min‐25, ES = 0.73), and adv. post‐PHV (min‐20, ES = 1.03; min‐25, ES = 0.65). Significant interactions at 25 min (p = 0.033, 0.047) showed that RWU outperformed SWU, especially in younger groups (pre‐PHV, mid‐PHV). RWU was superior to SWU for the reactive strength index at 20 min (p = 0.042) and 25 min (p = 0.047), with females having lower RSI than males at 20 min (p = 0.008, p = 0.015) and 25 min (p = 0.049) in later developmental stages. The flight distance (p = 0.009) and horizontal hip velocity (p = 0.014) revealed significant three‐way interactions, with the male adv. post‐PHV group responding better to RWU. Knee angular velocity was also higher after RWU, with male adv. post‐PHV group showing more pronounced improvements (p = 0.016). These results suggest that though RWU had higher influence in male adults, it is a valuable approach for varying ages athletes.
AbstractThis study aimed (i) to analyze the 1500 m open water swimming performance, (ii) to examine the associations between physiological and biomechanical variables with swimming performance, and (iii) to determine which variables can predict swimming performance in triathletes. Fourteen elite triathletes (23.4±3.8 y) performed a 1500 m test in open water swimming conditions. Swimming performance was assessed using World Aquatics Points Scoring, and data were obtained from the 1500 m open water swimming test. Heart rate, end-exercise oxygen uptake (EE˙VO2) and blood lactate concentrations were measured. The initial 250 m of the 1500 m swimming test presented the highest values of biomechanical variables in males (i. e. swimming speed, stroke rate (SR), length (SL), index (SI)). A decrease in SL was observed in the last 250 m in both sexes. Positive association were found between EE˙VO2 (r=0.513; p=0.030), swimming speed (r=0.873; p<0.001) and SI (r=0.704; p=0.002) with swimming performance. In contrast, time constant of the oxygen uptake (r=−0.500; p=0.034) and buoy-turn times (r=−0.525; p=0.027) were negatively associated with performance. SI was the main predictor (R 2=0.495) of open water swimming performance in triathletes. In conclusion, triathletes and coaches must conduct open water training sessions to maximize SI (i. e. swimming efficiency).
ABSTRACTThis study aimed to compare performance, kinematic, and physiological variables between open water and pool swimming conditions in elite triathletes and to examine the associations between conditions on these variables. Fourteen elite triathletes (10 males and 4 females [23.4 ± 3.8 years]) performed two 1500‐m swimming tests in open water and in a 25‐m pool. Swimming speed, stroke rate (SR), length (SL) and index (SI), heart rate (HR), blood lactate concentrations [La−], and end‐exercise oxygen uptake (EEV̇O2) were assessed in both conditions. Lower SL and SI and higher SR were obtained in open water compared with pool swimming (p < 0.05). Moreover, kinematic variables changed as a function of distance in both conditions (p < 0.05). No differences were found in the main physiological variables (HR, [La−], and EEV̇O2) between conditions. Respiratory exchange ratio presented lower values in open water than in pool conditions (p < 0.05), while time constant was higher in open water (p = 0.032). The fastest triathletes in open water obtained the best performance in the pool (r = 0.958; p < 0.001). All kinematic variables, HR and peak [La−] presented positive associations between conditions (r > 0.6; p < 0.05). Despite physiological invariance, triathletes and coaches should monitor specific open water training to adapt their swimming technique to the competitive environment.
Purpose: To explore the association of the load–velocity (L-V) relationship variables and ability to maintain maximal mechanical performance during the prone bench-pull exercise with sprint swimming performance and in-water forces. Methods: Eleven competitive adult male swimmers (50-m front crawl World Aquatics points: 488 [66], performance level 4) performed 1 experimental session. The L-V relationship variables (L0 [ie, maximal theoretical load at 0 velocity]; v0 [ie, maximal theoretical velocity at 0 load], and Aline [ie, area under the L-V relationship]) and maximal mechanical maintenance capacity were assessed at the beginning of the session. Afterward, sprint swimming performance and in-water force production were tested through a 50-m front-crawl all-out trial and 15-s fully-tethered swimming, respectively. Results: Only v0 presented high positive associations with 50-m time and swimming kinematics (r > .532; P < .046). The L0, v0, and Aline showed very high positive associations with the in-water forces during tethered swimming (r > .523; P < .049). However, the ability to maintain maximal mechanical performance, assessed by the mean velocity decline during the prone bench pull, was only significantly correlated with stroke rate (r = −.647; P = .016) and stroke index (r = .614; P = .022). Conclusions: These findings indicate that maximal neuromuscular capacities, especially v0, have a stronger correlation with swimming performance and in-water force production than the ability to maintain maximal mechanical performance in level 4 swimmers.
ABSTRACT This study aimed 1) to examine variables that may quantify the ability to apply force in the water and 2) to test their relationship with free swimming performance. Sixteen regional-level swimmers participated in this study. Average (Favg) and maximum (Fmax) forces were measured for 30 s arm stroke tethered swimming in a flume at zero and 1.389 m/s water flow speeds. The maximum and average force’s relative changes (ΔFmax and ΔFavg, respectively) were calculated between tethered swimming at zero and 1.389 m/s water flow speeds. Free swimming speeds were obtained from 25, 50, and 100 m front crawl trials, and were correlated with ΔFmax and ΔFavg. A negative correlation was found between ΔFmax and 25, 50 and 100 m speeds (r = -0.84, r = -0.74, r = -0.55; p < 0.05, respectively) and ΔFavg correlated negatively with 25 and 50 m speeds (r = -0.63, r = -0.54; p < 0.05, respectively), but it did not correlate with 100 m swimming speed. The relative change in force could be used to quantify the ability to apply force in the water. This could aid coaches to understand if changes in swimmers’ ability to apply force in the water contribute to improvements in performance.
ABSTRACT In swimming, the underwater phase after the start and turn comprises gliding and dolphin kicking, with the latter also known as underwater undulatory swimming (UUS). Swimming performance is highly dependent on the underwater phase; therefore, understanding the training effects in UUS and underwater gliding can be critical for swimmers and coaches. Further, the development of technique in young swimmers can lead to exponential benefits in an athlete’s career. This study aimed to evaluate the effects of a training protocol on UUS and underwater gliding performance and kinematics in young swimmers. Seventeen age group swimmers (boys = 10, girls = 7) performed maximal UUS and underwater gliding efforts before and after a seven-week training protocol. Time to reach 10 m; intra-cyclic mean, peak, and minimum velocities; and gliding performance improved significantly after the training protocol. The UUS performance improvement was mostly produced by an improvement of the upbeat execution, together with a likely reduction of swimmers’ hydrodynamic drag. Despite the changes in UUS and gliding, performance was also likely influenced by growth. The findings from this study highlight kinematic variables that can be used to understand and quantify changes in UUS and gliding performance.
This study aimed to evaluate the effects of a five-week training program on undulatory underwater swimming (UUS) in swimmers and to compare the specific effects prompted by two different training protocols on UUS performance and kinematics. Swimmers (n = 14) were divided into in-water only (WO) (18.61 ± 2.62 years, FINA points: 507 ± 60) and water + dry-land training groups (with conical pulleys) (WD) (18.38 ± 2.67 years, FINA points: 508 ± 83). Three countermovement jumps (CMJ) and three maximal UUS trials were performed before and after a five-week training period. The training program comprised 14 × 30-min sessions. The WO group repeated the same 15-min block twice, while the WD group performed one block of 15 min in the water and the other block on land performing lower limb exercises with conical pulleys. Seven body landmarks were auto-digitalized during UUS by a pre-trained neural network and 21 kinematic variables were calculated. The level of statistical significance was set at p < 0.05. Significant time × group interaction in favour of the WD group was observed for mean vertical toe velocity (p = 0.035, = 0.32). The WD group experienced enhancements in mean and maximum underwater velocity, kick frequency, maximum shoulder angular velocity, as well as mean and maximum vertical toe velocity (p < 0.05). The WO group exhibited an enhancement in CMJ height (p < 0.05). In conclusion, UUS performance was improved in adolescent swimmers after five weeks of specific training, only when combining water and conical pulley exercises. Coaches should include dry-land specific lower limb exercises in addition to in-water training to improve UUS performance.
The data that support the findings of this study are available from the corresponding author upon reasonable request.
ABSTRACT Competitive progressions are necessary to ensure that peak performance occurs when medals are decided. This study aimed to: i) study the coefficient of variation (CV) and performance changes (%Δ) among swimmers who participated in different rounds (i.e., heats, semi-finals and finals); ii) study the CV changes as a function of FINA-points. A total of 1447 performances were analysed in the 100 and 200 m-races during the Budapest 2021 European-Championships. Linear mixed-effects models were applied for total and split-times to obtain intra-athlete CV and %Δ. The FINA-points were studied with two-way ANOVA and Pearson’s correlation assessed the relations with CV. The CV in 100 m-races was: 0.48 ± 0.21% for males and 0.50 ± 0.20% for females (Δ = −0.66%); in 200 m-races: 0.63 ± 0.36% and 0.60 ± 0.34% (Δ = −0.82%). There were differences in FINA-points between strokes and distances (p < 0.02) associated with higher CV for the 200 m-races (r = 0.37; p = 0.003), indicating changes in performance over the rounds. Swimmers’ finalists performed easier during the heats by going slower in the first 50 m-lap; however, some of them would have little chance of qualifying during major championships because some events were below FINA-points world-standards.