Race analysis performed by faster and slower swimmers enables the definition of effective strategies for carrying out the competition. Until now, measurements of this type were mainly conducted among top-level athletes. The aim of the study was to determine the differences in swimming technique in sprint races between faster (FS) and slower (SS) regional-level swimmers. The performance of 33 swimmers (mean FINA points = 449) competing in 50 m and 100 m freestyle races was analysed. To determine the velocity (v), stroke rate (SR), stroke length (SL), and stroke index (SI), races were recorded with the use of cameras. Using the Student’s t-test and Mann–Whitney U test, the results were compared for two groups: FS (mean FINA points = 557) and SS (mean FINA points = 379). In the 100 m competition, differences between groups were noticed in v (1.70 and 1.51 m/s), SL (2.06 and 1.85 m), and SI (3.52 and 2.80 m²/s), while in the 50 m competition, they were noticed in v (1.95 and 1.73 m/s), SR (59.46 and 55.01 cycle/min), and SI (3.44 and 3.04 m²/s, respectively for the FS and SS groups). Adapting the technique to a shorter distance should be performed by increasing the frequency of movements. At the same time, the decrease in SL should be controlled. The indicator enabling the assessment of technical effectiveness, regardless of the distance, is the SI. The 50 and 100 m freestyle races require specific technical skills to be mastered. Therefore, the development of technique in swimmers should include its various variants.

Introduction Swim start technique analysis is usually conducted in elite swimmers or only limited to above-water phases. The aim of the study was to analyse kinematic parameters of above- and underwater kick start phases among young male swimmers. Material and methods The study group...

The study aim was establishing relationships between somatic build and kinematic indices describing underwater undulatory swimming (UUS). In a group of 47 young male swimmers (age = 17.2 ± 1.01, FINA points per 100 freestyle = 553 ± 94), anthropometric measurements were conducted. UUS was recorded through an underwater window. Movement modelling and its kinematic analysis were conducted using the SkillSpector. Velocity (v_COM), frequency (f), movement amplitude (A), distance per cycle (DPC) and product (I_Af) were determined. Anthropometric variable reduction was performed using principal component analysis (PCA). Then, a correlation matrix was created containing distinguished components and kinematic variables (p < 0.05). Intra-group variance was explained by 9 components (i.e. 90%), concerning indices of body size, adiposity and limb proportions. Few, weak relationships between principle components and kinematic indicators of UUS were proven. However, no component was found as related to v_COM. Simultaneously, all kinematic variables (f, A, DPC, I_Af) had influence on velocity, creating medium to strong correlations. Influence of swimmers’ somatic structure on UUS efficacy was small. Correct UUS technique was the main factor influencing effectiveness regarding the tested manner of movement. Therefore, an inseparable element of training young swimmers should be UUS technique exercises.

The construction of specialized physiological tests for swimmers is often based on those previously used in versions on land. So far, no attempt has been made to adapt the RAST test to conditions of an aquatic environment. The aim of the study was to evaluate the relationship between the results from the 6 × 25 m front crawl test (Swimming Anaerobic Sprint Test—SAST) and 100- and 200-m freestyle performance. In a group of 22 swimmers (9 girls, 13 boys, mean age 17.2 years, body mass 67.6 kg, body height 1.76 m), the SAST was performed (10-s interval between repetition). To determine speed (v), stroke rate (SR), stroke length (SL), and stroke index (SI), the test and races were recorded with the use of cameras. The analysis included times from the competition and fatigue indices (the decrease in SI during the SAST). Analysis of variance was performed, and a correlation matrix was created considering variables from the SAST and competition. The indices describing the 200-m event differed from those recorded for the SAST and 100 m freestyle race. The SAST results (v, SL, SI) were strongly correlated with the 100- and 200-m performances. Fatigue indices have not been shown to correlate with competition performance. The SAST may be useful in the context of predicting results for the 100- and, to a limited extent, 200-m freestyle races.

Purpose. The aim of the study was to distinguish the kinematic indicators influencing the average horizontal velocity of swimming (v_COM) with underwater dolphin kicks (UDK). Methods. The study involved 15 boys and 20 girls (mean age, 11.5 ± 1.00 years; height, 1.57 ± 0.09 m; training experience, 2.5 ± 1.00 years) practicing swimming 7 times a week. We determined the body height (H), the length of the body with the arms lifted (L_b), and the best result in the 50-m freestyle (pbt); characteristic anthropological points were marked on the body. The subjects performed UDK after a water-start for a distance of ca. 8 m (without a push-off from the wall). Movements were recorded with an underwater camera. The recordings were kinematically analysed with the SkillSpector program. On this basis, we calculated v_COM, frequency of movement (f), amplitude of movement (A), horizontal displacement in one cycle (Dpk), maximum flexion in the knee joints (KF_max), the product of f and A (I_Af), the Strouhal number (St), and relative amplitude of toe movement (A_REL). Results. The movements of the subjects were characterized as follows: v_COM = 1.08 ± 0.13 m/s, f = 2.00 ± 0.39 Hz, A = 0.46 ± 0.08 m, Dpk = 0.58 ± 0.10 m, I_Af = 0.90 ± 0.11, KF_max = 71.37 ± 9.15°, St = 0.83 ± 0.08, A_REL = 0.22 ± 0.04. A statistically significant correlation was found between v_COM and: H (r = 0.35), pbt (r = -0.52), f (r = 0.47), I_Af (r = 0.72), KF_max (r = -0.53), and St (r = -0.36). Conclusions. UDK of young swimmers is characterized by low-speed swimming. This is effected by low swimming efficiency (low values of IAf and St, high value of KFmax). The proper amplitude and frequency of movements should be a priority in improving UDK. The UDK technique should be particularly enhanced among short competitors.

The purpose of this study was to examine the relationship between a unique complex of predictors and 100 m front crawl race kinematics and swimming speed. In 28 male competitive swimmers (age: 19.6 ± 2.59 years), the following groups of predictors were assessed: (a) the morphologic, (b) the functional upper limb range of motion, and (c) the anaerobic indices of arm-cranking and a series of countermovement jumps. The Pearson product-moment correlation coefficient was calculated to distinguish the predictors and the swimming results. The main finding was that the indices of the power (arm-cranking) and the work (countermovement jump) generated in the anaerobic tests showed a significant and higher correlation with stroke length and stroke index than total body length, upper limb range of motion, or hand and forearm surface area. These results were obtained in accordance with the high swimming economy index relation to clear surface swimming speed. This study reveals that the strength generated by the limbs may represent a predictor of swimming kinematics in a 100 m front crawl performance.