200-m Front Crawl Research Articles

Reliability of using a pressure sensor system to measure in-water force in young competitive swimmers.

The aim of this study was to analyze the reliability of using a differential pressure system to measure in-water force in young competitive swimmers. Ten boys and five girls (12.38 ± 0.48years, 49.13 ± 6.82kg, 159.71 ± 7.99cm) were randomly assigned to perform two maximum bouts of 25m front crawl on different days (trial one, T1; trial two, T2), one week apart. A differential pressure system composed of two hand sensors (Aquanex System, v.4.1, Model DU2, Type A, Swimming Technology Research, Richmond, VA, United States) was used to measure the peak (RFPEAK) and the mean (RFMEAN) resultant force of the dominant and non-dominant hands (in Newton, N). Reliability was analyzed by computing the intraclass correlation coefficient (ICC), typical error (TE), smallest worthwhile change (SWC), coefficient of variation (CV%), standard error of measurement (SEM), and the minimal detectable change (MDC). Bland-Altman plots with 95% limits of agreement were also analyzed. The results showed no differences between T1 and T2 in all variables (p > 0.05). The ICC showed "excellent" reliability (ICC > 0.90) for the RFPEAK and RFMEAN in both hands. The CV% was rated as "good" (<5%) and TE was smaller than SWC in all variables. The Bland-Altman plots showed high reliability with a small bias (RFPEAK dominant, -0.29 N; RFPEAK non-dominant, -0.83 N; RFMEAN dominant, 0.03 N; RFMEAN non-dominant, 0.50N). The pressure sensor system (Aquanex System) seems to be a reliable device for measuring the hand resultant force during front crawl in young swimmers and can be used to monitor the changes over time.

Maturation-based Corrective Adjustment Procedures (Mat-CAPs) in youth swimming: Evidence for restricted age-group application in females.

Inter-individual differences in maturation-associated development can lead to variations in physical performance, resulting in performance (dis)advantages and maturation selection bias within youth sport systems. To address such bias and account for maturational differences, Maturation-based Corrective Adjustment Procedures (Mat-CAPs) could be beneficial. The present study aimed to: (1) determine maturity timing distributions in youth female swimming; (2) quantify the relationship between maturation status and 100-m front-crawl (FC) performance; (3) implement Mat-CAPs to remove maturational influences upon swimming performance. For Aim 1 and 2, participants were 663 female (10–15 years) swimmers who participated in 100-m FC events at Australian regional, state, and national-level competitions between 2016–2020 and underwent anthropometric assessment (mass, height and sitting height) to estimate maturity timing and offset. For Aim 3, participants aged 10–13 years were categorised into maturity timing categories. Maturity timing distributions for Raw (‘All’, ‘Top 50%’ and ‘Top 25%’) and Correctively Adjusted swim times were examined. Chi-square, Cramer’s V and Odds Ratios determined the presence of maturation biases, while Mat-CAPs identified whether such biases were removed in targeted age and selection-groups. Results identified that between 10–13 years, a significantly higher frequency of ‘early’ maturers was apparent, although tapered toward higher frequencies of ‘Late-normative’ maturers by 14–15 years. A curvilinear relationship between maturity-offset and swim performance was identified (R2 = 0.51, p<0.001) and utilised for Mat-CAPs. Following Mat-CAPs application, maturity timing biases evident in affected age-groups (10–13 years), and which were magnified at higher selection levels (‘Top 50%’ & ‘25%’ of swim performances) were predominantly removed. Findings highlight how maturation advantages in females occurred until approximately 13 years old, warranting restricted Mat-CAPs application. Mat-CAPS has the potential to improve female swimmer participation experiences and evaluation.

Biophysical Impact of 5-Week Training Cessation on Sprint Swimming Performance.

To assess changes in swimming performance, anthropometrics, kinematics, energetics, and strength after 5-week training cessation. Twenty-one trained and highly trained swimmers (13 males: 17.4 [3.1]y; 50-m front crawl 463 [77] FINA points; 8 females: 16.7 [1.7]y; 50-m front crawl 535 [48] FINA points) performed a 50-m front-crawl all-out swim test, dryland and pool-based strength tests, and 10-, 15-, 20-, and 25-m front-crawl all-out efforts for anaerobic critical velocity assessment before and after a 5-week training cessation. Heart rate and oxygen uptake (V˙O2) were continuously measured before and after the 50-m swim test (off-kinetics). Performance was impaired 1.9% (0.54s) for males (P = .007, d = 0.91) and 2.9% (0.89s) for females (P = .033, d = 0.93). Neither the anthropometrical changes (males: r2 = .516, P = .077; females: r2 = .096, P = .930) nor the physical activities that each participant performed during the off-season (males: r2 = .060, P = .900; females: r2 = .250, P = .734) attenuated performance impairments. Stroke rate and clean swimming speed decreased (P < .05), despite similar stroke length and stroke index (P > .05). Blood lactate concentrations remained similar (P > .05), but V˙O2 peak decreased in females (P = .04, d = 0.85). Both sexes showed higher heart rate before and after the 50-m swim test after 5 weeks (P < .05). Anaerobic metabolic power deterioration was only observed in males (P = .035, d = 0.65). Lower in-water force during tethered swimming at zero speed was observed in males (P = .033, d = 0.69). Regarding dryland strength, lower-body impairments were observed for males, while females showed upper-body impairments (P < .05). A 5-week training cessation yielded higher heart rate in the 50-m front crawl, anaerobic pathways, and dryland strength impairments. Coaches should find alternatives to minimize detraining effects during the off-season.

Tethered force at lower limbs and swimming during a 30 s exercise bout and its association with 50 m front crawl performance

BACKGROUND: The capacity to produce force should be promoted especially for the fastest swimming events. AIM: This study aimed to analyze the effects of different test periods in mean, maximal and coefficient of force variation and to correlate the coefficient of force variation and 50m front crawl time. METHOD: Twelve well trained swimmers (age: 22.33±8.08 years, 1.69±0.48 m height, body mass 56.08±7.86 kg) randomly performed three maximal 30s repetitions of full swimming and lower limbs actions in front crawl swimming technique with ~15min resting period. A load cell system permitted the continuous measurement of exerted tethered forces, and 50m time was registered as the best time obtained at 12 months before the test. RESULTS: Mean swimming force was greater at 10s compared to 20 and 30s period (26.40 [20.66-54.20], 25.33 [21.70-52.35] and 21.39 [17.91-43.98] respectively, p&lt;0.05). Mean, maximal and force coefficient variation at tethered test with full swimming were higher than lower limbs (24.37 vs. 12.71, 77.97 vs. 39.78, 0.77 vs. 0.49 respectively, p&lt;0.05). Strong and inverse correlations were noticed between coefficient of force variation at 10 s during full swimming, at 20s during kicking and performance (28.75s [26.20-30.68s];r=-0.75;p&lt;0.01). Very strong correlation was noticed between coefficient of force variation during swimming at 20s, 30s and performance (r=-0.91 and -0.92;p&lt;0.0001). CONCLUSION: Mean swimming force at full swim and lower limbs is affected by the period of the 30s maximal tethered swimming test and is associated with performance.Data reported may be used as reference for setting training strategies at short distance events.

Body composition and anthropometrics of young male swimmers in relation to the tethered swimming and kinematics of 100-m front crawl race.

The aim was to analyze the relationship of body mass and predicted muscle mass of body segments on swimming kinematics and tethered swimming indices, and further assess the influence of those indices on 100-m front crawl performance of adolescent male swimmers. In 19 volunteer swimmers (age: 13.5±0.44 years, height: 168.6±7.77 cm, body mass: 56.9±10.57 kg), the predicted muscle mass of body segments was assessed with bioelectrical impedance analysis. The kinematic indices of swimming (stroke rate - SR, stroke length - SL, and stroke index - SI) were calculated from a video recording of a 100-m front crawl race. The strength indices (maximum and average value of force, average impulse per single cycle, force decline) were collected in a 30-second front crawl tethered swimming test. The average tethered swimming force was positively correlated with surface swimming speed (0.505; P≤0.05). Indices of SL, SI were influenced by average impulse per single cycle (0.58, 0.55; P≤0.05), and further the SI was strongly correlated with most specified speed indices of the 100-m race (0.59; P≤0.05). It can be stated that the ability of force development in a single stroke, owing to strong interrelation with SI, is a good predictor in talent identification among young swimmers.

Effects of Dryland Training During the COVID-19 Lockdown Period on Swimming Performance.

To examine the effect of dryland training during an 11-week lockdown period due to COVID-19 on swimming performance. Twelve competitive swimmers performed 50- and 300-m maximum-effort tests in their preferred stroke and 200-, 400-, and four 50-m front crawl sprints (4 × 50m) before and after the lockdown period. Critical speed as an index of aerobic endurance was calculated using (1)50-, 300-, and (2)200-, 400-m tests. Blood lactate concentration was measured after the 400- and 4 × 50-m tests. To evaluate strength-related abilities, the dryland tests included handgrip and shoulder isometric strength. Tethered swimming force was measured during a 10-second sprint. During the lockdown period, dryland training was applied, and the session rating of perceived exertion training (sRPE) load was recorded daily. sRPE training load during the lockdown was decreased by 78% (16%), and critical speed was reduced 4.7% to 4.9% compared to prelockdown period (P < .05). Performance time in 200, 300, and 400m deteriorated 2.6% to 3.9% (P < .05), while it remained unaltered in 4 × 50- and 50-m tests (P > .05). Tethered force increased 9% (10%) (P < .01), but handgrip and shoulder isometric force remained unaltered (P > .05). Blood lactate concentration decreased 19% (21%) after the 400-m test and was unchanged following the 4 × 50-m tests (P > .05). Performance deterioration in the 200, 300, and 400m indicates reduced aerobic fitness and impaired technical ability, while strength and repeated-sprint ability were maintained. When a long abstention from swimming training is forced, dryland training may facilitate preservation in short-distance but not middle-distance swimming performance.

The Effect of a Coordinative Training in Young Swimmers' Performance.

This study investigated the effects of a coordinative in-water training. Total 26 young swimmers (16 boys) were divided in a training group (that performed two sets of 6 × 25-m front crawl, with manipulated speed and stroke frequency, two/week for eight weeks) and a control group. At the beginning and end of the training period, swimmers performed 50-m front crawl sprints recorded by seven land and six underwater Qualisys cameras. A linear mixed model regression was applied to investigate the training effects adjusted for sex. Differences between sex were registered in terms of speed, stroke length, and stroke index, highlighting that an adjustment for sex should be made in the subsequent analysis. Between moments, differences were noticed in coordinative variables (higher time spent in anti-phase and push, and lower out-of-phase and recovery for training group) and differences between sex were noticed in performance (stroke length and stroke index). Interactions (group * time) were found for the continuous relative phase, speed, stroke length, and stroke index. The sessions exerted a greater (indirect) influence on performance than on coordinative variables, thus, more sessions may be needed for a better understanding of coordinative changes since our swimmers, although not experts, are no longer in the early learning stages.

The relationship between tethered swimming, anaerobic critical velocity, dry-land strength, and swimming performance

ABSTRACT This study aimed to 1) examine the associations between two swim-specific measures of anaerobic performance and dry-land strength-based variables; 2) study the association between the aforementioned variables with swimming performance and its kinematics; 3) analyse sex-induced differences. Twenty-three regional-national swimmers performed five countermovement-jumps and pull-ups, 50-m front crawl, two 30-s tethered-swimming tests at 0 and 1.124 m·s−1 water flow speed. Moreover, 10, 15, 20, and 25-m maximal front crawl were performed to determine anaerobic critical velocity (AnCV). The AnCV was positively correlated with tethered swimming variables in both conditions and dry-land-based variables in both sexes (p < 0.05). Tethered-swimming variables in both conditions were correlated with pull-ups’ average propulsive force in males (p < 0.05). 50-m swimming performance was positively associated with AnCV, tethered-swimming variables, countermovement-jump height, and pull-ups’ average propulsive force for both sexes (p < 0.05). Stroke rate (SR) was positively associated with AnCV in males and females (p < 0.05). Stroke length was correlated with tethered-swimming variables in males (p < 0.05). Except for SR, males presented higher values than females (p < 0.05). Depending on the conditions of their training environment, coaches might use the AnCV and tethered-swimming variables as interchangeable tools for evaluating anaerobic performance.

Metabolic, kinematic and coordinative behavior of a para swimmer with cerebral palsy

BACKGROUND: It has been increasingly necessary to assess and monitor the physiological and biomechanics variables of para swimmers to enlarge the current knowledge on how different impairments limit swimming performance and explain each competition class variability in metabolic and technical terms. AIM: To characterize the front crawl metabolic, kinematic, and coordination behaviors of a trained para swimmer subjected to an incremental protocol. METHOD: A 44-year-old male, with moderate right side hemiparesis of the body, performed a 200-m front crawl at 5 incrementally paces until exhaustion (0.05 m/s increases and 30-s intervals), with images from two cycles at each step recorded by two video cameras (one surface and one underwater). Kinematic and coordinative variables were collected. Lactate concentrations, heart rate, and blood pressure were also measured. RESULTS: The para swimmer achieved the anaerobic threshold at the fourth 200-m step, followed by an increase in heart rate and blood pressure. Speed and stroke frequency were higher and stroke length was lower along the 200-m steps. In contrast, a slight increase in stroke index and stability in intracyclic velocity variations occurred across intensity increments, and index of interlimb coordination was maintained as a superposition mode. CONCLUSION: The findings suggest that the swimming intensity seems to influence the para swimmer metabolic, kinematic, and coordinative behavior, with sharper alterations after the point when AnT is achieved. In addition to having practical interest for adapted swimming, coaches should emphazise the physiological and biomechanical evaluation on training monitoring to better prescribe and improve the adapted swimming performance.

VO2 kinetics and bioenergetic responses to sets performed at 90%, 92.5%, and 95% of 400-m front crawl speed in male swimmers

VO2 kinetics and bioenergetic responses to sets performed at 90%, 92.5%, and 95% of 400-m front crawl speed in male swimmers

200-m front crawl performance over a training season in 12 years and underage-group swimmers: growth and kinematics effects

Aims: analyze kinematics, anthropometrics, and maturation during a training season in 12 y and underage-group swimmers, quantifying changes and estimating their contributions to the 200-m maximal front crawl time trial test (T200) (time trial/fixed distance), as an event representative of the swimming performance. Methods: Nineteen age-group swimmers (11 girls and 8 boys; age 10.0 ± 1.3 y and 10.6 ± 1.0 y) performed a T200 four times during the training season. Changes in kinematic and anthropometric variables throughout the season were calculated. We applied generalized estimating equations to compare the variables over the four experimental tests. Multiple linear regressions were applied to identify the most influential variables and the relative contribution of anthropometrics and kinematics to swimming performance of T200 at baseline (pre-season) and after (using delta values) each macrocycle. Results: Large improvements (d = 1.76) were observed in the T200's performance (from 85.5 ± 38.2 at pre-season to 175.2 ± 50.1 FINA points at the end season). A gender effect was not identified. Stroke rate, stroke length, and stroke index explained, respectively 59, 23, and 17% of the T200 performance changes along the season (R2 = 0.81; F = 26.9; p < 0.001; Durbin-Watson: 1.5). Anthropometric was not related to performance changes, with kinematic being the most determinant factor. Conclusion: Kinematical approaches must be carefully considered by coaches when planning 12 y and underage-group swimmers training programs.

Study of talented young male swimmers – scientific approach to the kinematic and physiological predictors of 400-m front crawl race

Purpose: The purpose of this study was to assess the influence of physiological and kinematic predictors on 400-m front crawl race in young male swimmers and to consider the interrelation between them. Methods: Nineteen male swimmers took part in this study (age: 13.5 ± 0.44 years, height: 168.6 ± 7.77 cm, body mass: 56.9 ± 10.57 kg). Measurements of physiological parameters were conducted using expired air analyzer (Start 2000 MES, Poland) during step-test in water flume. Kinematic indices were computed while analyzing video recording of 400-m front crawl race. To check for possible influence of biological age (BA) diversity in studied group, partial correlation with age control was computed. Results: Swimming to exhaustion in water flume defined as speed at maximum oxygen uptake and anaerobic threshold (VO2 max V &amp; and VAT) occurred to be strongly positively correlated with 400-m race speed. Speed in surface swimming zones (Vsurface) was related to ability of kinematics adjustment and significantly correlated with stroke index (SI). Vsurface at the beginning and the end of the race, i.e., at 1st, 7th and 8th lap interplayed with stroke rate (SR) measured at corresponding laps. Conclusions: Our study showed that 400-m front crawl performance of young male swimmers is strongly dependent on swimming efficiency developed with aerobic conditioning. Significant role of proper pacing strategy was also identified, which indicates that race pace training should be implemented.

The Impact of Assisted Swimming on Front Crawl Performance

Background: In the present study, we aimed to clarify the impact of the Assisted swim (A-swim; towing from propulsion direction) on front crawl performance at maximum and sub-maximum effort levels. Methods: Fourteen male collegiate swimmers (age, 21.0 ± 2.0 years; height, 1.73 ± 0.05 m; weight, 67.1 ± 7.1 kg) participated. Participants swam 25-m front crawl at maximal (Max) and submaximal intensity (Submax (80% of the max stroke rate (SR))) with and without an assist (assisted swimming with a towing device and normal swim (N-swim) without the device) for a total of four lengths. In addition to swim velocity (V), SR, and stroke length (SL), one stroke cycle was broken down into four phases—glide, pull, push, and recovery—and analyzed the duration of each phase. Results: A significant interaction of level of efforts and presence/absence of towing was confirmed in V, SR, and SL. V and SL showed a significant increase in A-swim compared to N-swim at both Max and Submax. SR was significantly higher in A-swim than in N-swim only at Max. Each phase of stroke showed a significant difference in recovery at Submax and push at Max. Conclusions: Despite considering the impact of propulsion from towing, A-swim increased SR, in addition to the V and SL, of swimmers compared with N-swim.

Specific and Holistic Predictors of Sprint Front Crawl Swimming Performance.

The aim of the study was to examine the impact of selected water- and dry-land predictors of 50-m front crawl performance among 27 male swimmers aged 19.3 ± 2.67 years. The following water tests were performed: front crawl tethered arm stroking in a water flume (flow velocity: 0.9 m·s–1) and leg tethered flutter kicking in a swimming pool. Anaerobic tests on dry land included arm cranking and a set of 10 countermovement jumps. The maximal and average forces generated by legs in tethered swimming (Fl max and Fl ave) turned out to be the strongest predictors of sprint swimming aptitude. These values were strongly correlated with total speed (Vtotal50) (r = 0.49, p < 0.05 and r = 0.54, p < 0.01, respectively), start, turn, and finishing speed (VSTF) (r = 0.60, p < 0.01 and r = 0.67, p < 0.01, respectively). The relationship of Fl max and Fl ave with surface speed (Vsurface) was moderate (r = 0.33, non-significant and r = 0.41, p < 0.05, respectively). The maximal force generated by arms (Fa max) during flume tethered swimming significantly influenced Vsurface and Vtotal50 (0.51, p < 0.01 and 0.47, p < 0.05, respectively). Its relationship with VSTF was close to significant (0.36, p = 0.07). Upper and lower limb dry-land tests showed lower and more holistic relationships with the 50-m front crawl race, however, being a good complement to overall fitness assessment. Specific in-water evaluation, especially the newly prepared flutter kicking test, as well as dry-land tests, can be applied to regularly monitor progress in swimming training, and to identify talented swimmers.

Longitudinal Relationships Between Maturation, Technical Efficiency, and Performance in Age-Group Swimmers: Improving Swimmer Evaluation.

The study aimed to (1)accurately examine longitudinal relationships between maturity status and both technical skill indices and performance in Australian male (N = 64) age-group Front-crawl swimmers (10-15y) and (2)determine whether individual differences in maturation influenced relationships between technical skill level and swimming performance. A repeated-measures design was used to assess maturity status and performance on 200-m Front-crawl trial across 2 competition seasons (2018-2020). Assessments were made on 3 to 5 occasions (median = 3) separated by approximately 4 months. Average horizontal velocity and stroke frequency were used to calculate technical skill indices, specifically stroke index, and arm propelling efficiency. Relationships between variables were assessed using linear mixed models, identifying fixed, and random effect estimates. Curvilinear trends best described significant longitudinal relationships between maturity status with horizontal velocity (F = 10.33 [1, 233.77]; P = .002) and stroke index (F = 5.55 [1, 217.9]; P = .02) during 200-m Front-crawl trials. Maturity status was not significantly related to arm propelling efficiency (P = .08). However, arm propelling efficiency was an independent predictor of Front-crawl velocity (F = 55.89 [1, 210.45]; P < .001). Maturity status predicted assessment of swimmer technical skill (stroke index) and swimming performance. However, technical skill accessed via arm propelling efficiency was independent of maturation and was predictive of performance. Maturity status influences performance evaluation based on technical skill and velocity. Findings highlight the need to account for maturation and technical skill in age-group swimmers to better inform swimmer evaluation.

Does a jammer-type racing swimsuit improve sprint performance during maximal front-crawl swimming?

ABSTRACT We investigated the effects of jammer-type racing swimsuits (RS) on swimming performance during arm-stroke-only (pull) and whole-body stroke (swim) in 25-m front-crawl with maximal effort. Twelve well-trained male collegiate swimmers wore RS and a conventional swimsuit (CS) and performed three tests: pull, swim, and pull using the system to measure active drag (MAD pull). Swimming velocity and intra-abdominal pressure (IAP) were determined in all tests. Stroke indices during pull and swim and drag–swimming velocity relationship and maximum propulsive power during MAD pull were also determined. Swimming velocities during pull and swim while wearing an RS (1.59 ± 0.13 and 1.77 ± 0.09 m·s−1, respectively) were significantly higher than those wearing a CS (1.57 ± 0.14 and 1.74 ± 0.08 m·s−1, respectively). Stroke length during pull and swim was significantly greater while wearing an RS (1.68 ± 0.12 and 1.83 ± 0.13 m, respectively) than wearing a CS (1.63 ± 0.10 and 1.81 ± 0.13 m, respectively). However, no significant differences were confirmed between the other variables in all tests. In conclusion, swimming performance is improved when wearing an RS compared with a CS.

Energy contributions in swimmers with physical impairments in an all-out 200-m front crawl test

In competitive swimming, performance is associated with swimming a certain distance in the shortest possible time. Specifically, in an all-out 200-m front crawl test (T200), the intensity and duration of effort represent a challenge for coaches and swimmers to balance swimming speed with the ability to use different energy sources (aerobic and anaerobic) with lower energy cost (C). In the case of swimmers with physical impairments, physiological parameters are still little explored, and their monitoring may allow a better understanding of performance. The aim of this study was to assess the total metabolic energetic contribution (Etot) and C of swimmers with physical impairments in a T200. Eleven swimmers (7 males and 4 females; age: 32.3 ± 12.3 years) with physical impairments performed a T200 with the use of a snorkel and respiratory valve system. Measurements were performed for peak oxygen uptake (VO2peak), blood lactate concentration (La), Etot and C. The performance was 210.2 ± 48.1 s (swimming speed 0.99 ± 0.14im·s−1). The aerobic, anaerobic lactic and anaerobic alactic contributions were 70.1%, 17.1% and 12.8%, respectively. C was 1.22 ± 0.52 kJ m−1. Swimmers with physical impairment of different sport classes presented, predominately, high aerobic metabolism contribution to the Etot and different values of C, with a certain tendency of C being lower in those faster swimmers than in slower swimmers. Possible divergences in this trend seem to be explained by the different competitive levels, body position and upper limb impairment.

Arm-Stroke Descriptor Variability during 200-m Front Crawl Swimming.

The present study aimed to explore the variability of the arm-stroke temporal descriptors between and within laps during middle-distance swimming event using IMMUs. Eight male swimmers performed a 200-m maximum front-crawl in which the inter-lap and intra-lap variability of velocity, stroke rate, stroke-phases duration and arm-coordination index were measured through five units of IMMU. An algorithm computes the 3D coordinates of the wrist by means the IMMU orientation and the kinematic chain of upper arm biomechanical model, and it recognizes the start events of the four arm-stroke phases. Velocity and stroke rate had a mean value of 1.47 ± 0.10 m·s−1 and 32.94 ± 4.84 cycles·min−1, respectively, and a significant decrease along the 200-m (p < 0.001; η2 = 0.80 and 0.47). The end of each lap showed significantly lower stroke rate compared to the start and the middle segment (p < 0.05; η2 = 0.55). No other significant inter-lap and intra-lap differences were detected. The two main findings are: (i) IMMUs technology can be an effective solution to continuously monitor the temporal descriptors during the swimming trial; (ii) swimmers are able to keep stable their temporal technique descriptors in a middle-distance event, despite the decrease of velocity and stroke rate.

Effect of a short ischaemic preconditioning protocol on 100-m front crawl performance

PurposeThe aim of our study was to analyse the effect of a single-cycle ischaemic preconditioning (IPC) protocol on performance in the 100-m front crawl swimming modality.MethodsOverall, 16 swimmers were recruited: 8 female athletes (12.9 ± 0.88 years) and 8 male athletes (13.1 ± 0.88 years). In a randomized crossover design, all participants performed a 100-m front crawl sprint preceded by an IPC or placebo cycle. In the IPC trial, a pneumatic cuff was attached to the proximal thigh and was inflated at a pressure equivalent to 80% of arterial occlusion and remained inflated for 5 min (ischaemia); in the placebo trial, the cuff remained inflated for the same amount of time, but at low external pressure levels (20 mm Hg). The volunteers started the test 5 min after cuff pressure release (reperfusion).ResultsIt was not possible to verify significant differences within the time (seconds) required to complete the test between the IPC and placebo interventions (75.68 ± 7.2 and 75.75 ± 8.1 s, respectively; &lt;i&gt;p&lt;/i&gt; = 0.916).ConclusionsTherefore, we can conclude that the tested IPC protocol does not seem to be sufficient to provide performance improvement in 100-m front crawl in young athletes.

Comparison of swimming velocity and stroke rate and length in the 50-m front crawl by age in Japanese competitive swimmers

Comparison of swimming velocity and stroke rate and length in the 50-m front crawl by age in Japanese competitive swimmers