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 (V˙O2) kinetics and tethered swimming strength. Furthermore, the interplay between swimming strength, V˙O2, and 400-m front crawl race performance was examined. Methods: The study involved 36 competitive young male swimmers (metrical age: 12.9 ± 0.56 years). Depending on BA examination, the group was divided into early-mature (BA: 15.8 ± 1.18 years, 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 V˙O2 (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 V˙O2 and F ave. Conversely, when V˙O2 was present relatively to body mass and pulling force (in ml∙min-1∙kg-1∙N-1), late-mature swimmers showed higher O2 relative usage. Late-mature swimmers generally exhibited a slower increase in V˙O2 during the first 30 s of 60 s. V˙O2, 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 V˙O2 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 V˙O2 kinetics and tethered swimming force were further translated into 400-m front crawl speed and stroke length kinematics.

Correlations between Crawl Kinematics and Speed with Morphologic, Functional, and Anaerobic Parameters in Competitive Swimmers.

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.

Biological Age in Relation to Somatic, Physiological, and Swimming Kinematic Indices as Predictors of 100 m Front Crawl Performance in Young Female Swimmers.

BACKGROUND: Some swimmers reach high performance level at a relatively young age. The purpose of this study is to determine the relationship between adolescent female swimmers' 100 m front crawl race (Vtotal100) and several anthropometry, body composition, and physiological and specific strength indices. METHODS: Nineteen adolescent female swimmers were examined for biological age (BA) and body composition. Oxygen uptake was measured during water-flume stage-test front crawl swimming with ventilatory thresholds examination. Specific strength indices were assessed during 30 s of tethered swimming. Stroke rate (SR), stroke length (SL), and stroke index (SI) were also examined. RESULTS: BA was strongly correlated with anthropometrics and tethered swimming strength indices, and showed moderate to strong correlation with ventilatory thresholds. Speed of swimming in the race was moderately to largely correlated with speed at V˙O2 max-VV˙O2max (r = 0.47-0.55; p < 0.05)-ventilatory thresholds (VAT, VRCP) (r = 0.50-0.85; p < 0.05), SL (r = 0.58-0.62; p < 0.05), and SI (r = 0.79-0.81; p < 0.01). CONCLUSION: Results confirmed a significant role of biological maturation mediation on body composition and body size, ventilatory indices, and specific strength indices. BA was not a significant mediation factor influencing the swimming kinematics (SL, SI) and speeds of VAT, VRCP or VV˙O2 max, which were strong predictors of the 100 m race.

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.

Body composition and specific and general strength indices as predictors of 100-m front crawl performance.

PURPOSE: The purpose of this research was to examine the impact of body composition on the anaerobic ability to generate strength and power produced separately by upper and lower limbs during dry-land and in-water (propulsion force) tests. Further examination included the influence of all gathered anaerobic strength indices on the results of 100-m front crawl race. METHODS: The study involved 26 male swimmers (age: 19.8 ± 2.48 years). Fat-free mass, total body water and muscle mass of arms, legs, and trunk were measured. Dry-land average work, maximal power generated in 40-second arm-cranking test, and work generated in 20 countermovement jumps were evaluated. The forces generated separately by arms and legs were assessed during 40-second tethered swimming. All indices of body composition were found strongly correlated with indices of average work and maximal power generated by arms and legs in dryland tests. RESULTS: Muscle mass of arms and trunk moderately and strongly (r = 0.44-0.64) influenced the force generated by arms in tethered swimming. There was no significance in the relationship of leg muscle mass and force generated by legs in tethered swimming. Significant relationships were observed between the results of the 100-m front crawl and the muscle mass of the arms, trunk, legs, as well as the average work and maximal power in the arm-cranking test (r: 0.39-0.54). The average impulse of arm force and maximal leg force in tethered swimming moderately and significantly correlated with 100-m swimming results. CONCLUSIONS: The study concludes the relevance of developing muscle mass balanced to the body size, which is involved in propulsion force production in sprint front crawl swimming.

The Impact of Vibration Therapy Interventions on Skin Condition and Skin Temperature Changes in Young Women with Lipodystrophy: A Pilot Study.

BACKGROUND: Cellulite affects 85-98% of women aged over 20 years. In a given context, mechanical vibrations have not been applied in the therapy of gynoid lipodystrophy (GL) until now. The aim of this pilot study was to assess the condition and temperature of skin affected by cellulite after vibration therapy interventions in young women with GL. METHODS: 10 healthy women (21.5 ± 1.5 years old) with stage 1 or 2 Nürnberger-Müller scale of severity of GL participated in the study. The subjects underwent 20 vibration interventions with the use of a Rehabilitation Massage Device Vitberg+. Vibration therapy was applied 5 times a week for 60 minutes during 4-week period. Before and after first and last interventions, grade of lipodystrophy was assessed and thermographic images were taken. RESULTS: Visual and palpation analysis performed before and after a series of treatments proved a total cellulite remission after the intervention among 40% of subjects (from stage 1 to stage 0). Among the remaining 60% with stage 2 of cellulite, an improvement in the skin condition was observed, and cellulite grade was determined as stage 1. The mean skin temperature in the lateral part of thigh as well as on the posterior surface of thigh and buttocks increased significantly (p<0.00001) after both the first (respectively: 4.0°C ± 0.9°C, 3.9°C ± 0.8°C) and the last vibration therapy interventions (respectively: 3.1°C ± 1.1°C, 2.8°C ± 1.1°C). After the series of interventions, a statistical significant (p=0.00705) increase in the mean skin temperature in the lateral thigh was observed-before the first treatment: 27.9°C ± 0.7°C; before twentieth treatment: 29.0°C ± 1.2°C. CONCLUSION: The series of vibration interventions contributed to the reduction of GL among the participants. The thermographic imaging analysis proved an impact of both single and serial vibration interventions.

Influence of Morphology and Strength on Front Crawl Swimming Speed in Junior and Youth Age-Group Swimmers.

Strzala, M, Stanula, A, Krezalek, P, Ostrowski, A, Kaca, M, and Glab, G. Influence of morphology and strength on front crawl swimming speed in junior and youth age-group swimmers. J Strength Cond Res 33(10): 2836-2845, 2019-This study, conducted in 2 male age groups, was aimed at analyzing the influence of body properties, dry-land strength and swimming strength on 50-m crawl (VCrawl). We examined 2 competitive groups, Youth (20.6 ± 1.05) and Junior (17.3 ± 0.59), based on (a) body mass (BM) and lean body mass (LBM), body height (BH) and total body length (TBL), and arm span (AS); (b) countermovement jump (CMJ) and maximum isometric strength of elbow and knee joints; and (c) tethered crawl strength. We hypothesized that a higher relationship of strength indices in younger swimmers in VCrawl and tethered swimming would be a better sprint performance predictor. The Junior group revealed a significant relationship between somatic traits (BM r = 0.63; BH r = 0.55; TBL r = 0.58; AS r = 0.52 with p ≤ 0.05 LBM r = 0.78; with p < 0.01) and VCrawl, whereas such interplay was not found in the Youth group. General dry-land strength indices CMJ (cm), CMJ (J) or isometric strength of knee joint muscle flexors and extensors (r = 0.57; r = 0.69; r = 0.56; r = 0.57, respectively) also significantly correlated with VCrawl only in the Junior group. The Junior group's tethered swimming strength had a higher but not a significant relationship with VCrawl. The Youth group instead achieved significantly higher VCrawl and stroke rate (SR). The SR revealed (r = 0.41, p = 0.014) a relationship with VCrawl only after the combination of both groups. This study demonstrates a better strength relationship with VCrawl in the younger Junior group. In the future, the evaluation of sprint swimming aptitudes, besides on the basis of somatic traits and properties of dry-land or water strength measurement, should be complemented by measurements of real sprint swimming technique parameters.

Butterfly Sprint Swimming Technique, Analysis of Somatic and Spatial-Temporal Coordination Variables.

The aim of this study was to investigate somatic properties and force production of leg extensor muscles measured in the countermovement jump test (CMJ), as well as to analyse kinematic variables of sprint surface butterfly swimming. Thirty-four male competitive swimmers were recruited with an average age of 19.3 ± 1.83 years. Their average body height (BH) was 183.7 ± 5.93 cm, body fat content 10.8 ± 2.64% and body mass (BM) 78.3 ± 5.0 kg. Length measurements of particular body segments were taken and a counter movement jump (CMJ) as well as an all-out 50 m butterfly speed test were completed. The underwater movements of the swimmers' bodies were recorded with a digital camera providing side-shots. We registered a significant relationship between body mass (r = 0.46), lean body mass (r = 0.48) and sprint surface butterfly swimming (VSBF). The anaerobic power measured in the CMJ test, total body length (TBL) as well as upper and lower extremity length indices did not influence swimming speed significantly. The temporal entry-kick index (the time ratio between the first kick and arm entry) significantly influenced VSBF (r = -0.45). Similarly, medium power of the coefficient was indicated between a) stroke rate kinematics (SR), b) duration of the first leg kick (LP1), c) air phase duration of arm recovery (Fly-arm), and VSBF (r = 0.40; r = 0.40 and r = 0.41, respectively). The entry-kick temporal index showed that, in the butterfly cycle, an appropriately early executed initial kick when compared to arm entry was associated with a longer arm propulsion phase, which in turn was associated with minimizing resistive gliding phases and enabled relatively longer and less resistive air arm recovery (higher value of the fly-arm index). The higher value of SR kinematic was another important element of the best butterfly results in this study.

Propulsive limb coordination and body acceleration in sprint breaststroke swimming.

BACKGROUND: This work aimed at examining how coordination and kinematic indices interplay with swimming performance measured by average speed in 50 m all-out test. METHODS: The group of 34 male competitive swimmers (19.1±1.91 years old) participated in the study. The underwater movements of swimmers' bodies were recorded providing side-shots. Accelerations and angular velocity of pitch rotation of swimmer's sacrum were measured with inertial sensor device (three-axial accelerometer and gyroscope). RESULTS: Indices calculated on the basis of video analysis as well as their relationship with speed (V50surface breast) clearly show, that stroke rate (SR) kinematic and ample arm propulsion (AP) duration impulse are both highly associated with performance. At the same time V50surface breast is highly related to significant shortening inter-cycle gap - Glide or Overlap. The study shows, that sagittal maximal ventral acceleration (Azmax) and sagittal amplitude acceleration (Azamp) significantly interplay with V50surface breast (0.54, P<0.01 and 0.45, P=0.01 respectively), which is connected with dolphin-like body waving. CONCLUSIONS: The most important thing is to recognize possible gains coming from suitably shaped dolphin-like body waving, as well as to enhance this specific action during well-timed upper trunk and head immersion in each sprint breaststroke cycle.

Neurologic Music Therapy Training for Mobility and Stability Rehabilitation with Parkinson's Disease - A Pilot Study.

Idiopathic Parkinson's Disease (PD) is a progressive condition with gait disturbance and balance disorder as the main symptoms. Previous research studies focused on the application of Rhythmic Auditory Stimulation (RAS) in PD gait rehabilitation. The key hypothesis of this pilot study, however, assumes the major role of the combination of all three Neurologic Music Therapy (NMT) sensorimotor techniques in improving spatio-temporal gait parameters, and postural stability in the course of PD. The 55 PD-diagnosed subjects invited to the study were divided into two groups: 30 in the experimental and 25 in the control group. Inclusion criteria included Hoehn and Yahr stages 2 or 3, the ability to walk independently without any aid and stable pharmacological treatment for the duration of the experiment. In order to evaluate the efficacy of the chosen therapy procedure the following measures were applied: Optoelectrical 3D Movement Analysis, System BTS Smart for gait, and Computerized Dynamic Posturography CQ Stab for stability and balance. All measures were conducted both before and after the therapy cycle. The subjects from the experimental group attended music therapy sessions four times a week for 4 weeks. Therapeutic Instrumental Music Performance (TIMP), Pattern Sensory Enhancement (PSE) and RAS were used in every 45-min session for practicing daily life activities, balance, pre-gait, and gait pattern. Percussion instruments, the metronome and rhythmic music were the basis for each session. The subjects from the control group were asked to stay active and perform daily life activities between the measures. The research showed that the combination of the three NMT sensorimotor techniques can be used to improve gait and other rhythmical activities in PD rehabilitation. The results demonstrated significant improvement in the majority of the spatiotemporal gait parameters in the experimental group in comparison to the control group. In the stability tests with eyes closed, substantial differences were revealed, indicating improvement of proprioception (the sense of body position and movement). These findings suggest a new compensatory strategy for movement and postural control through the use of the auditory system.

Coordination and propulsion and non-propulsion phases in 100 meter breaststroke swimming.

PURPOSE: The main purpose of this study was to analyze the coordination, propulsion and non-propulsion phases in the 100 meter breaststroke race. METHODS: Twenty-seven male swimmers (15.7 ± 1.98 years old) with the total body length (TBL) of 247.0 ± 10.60 [cm] performed an all-out 100 m breaststroke bout. The bouts were recorded with an underwater camera installed on a portable trolley. The swimming kinematic parameters, stroke rate (SR) and stroke length (SL), as well as the coordination indices based on propulsive or non-propulsive movement phases of the arms and legs were distinguished. RESULTS: Swimming speed (V100surface breast) was associated with SL (R = 0.41, p < 0.05) and with TBL tending towards statistical significance (R = 0.36, p < 0.07), all relationships between the selected variables in the study were measured using partial correlations with controlled age. SL interplayed negatively with the limbs propulsive phase Overlap indicator (R = -0.46, p < 0.05), but had no significant relationship to the non-propulsion Glide indicator. CONCLUSIONS: The propulsion in-sweep (AP3) phase of arms and their non-propulsion partial air recovery (ARair) phase interplayed with V100surface breast (R = 0.51, p < 0.05 and 0.48 p < 0.05) respectively, displaying the importance of proper execution of this phase (AP3) and in reducing the resistance recovery phases in consecutive ones.

Intra-cyclic phases of arm-leg movement and index of coordination in relation to sprint breaststroke swimming in young swimmers.

Despite the limitations set by FINA regulations, execution technique in breaststroke swimming is being improved thanks to more and more advanced analyses of the efficiency of the swimmer's movements. The aim of this study was to detect the parameters of the time structure of the cycle correlated with the maximal swimming speed at the of 50 meters distance, in order to focus to specific technical aspects in the breaststroke training. In the group of 23 participants, between the age of 15.0 ± 1.17, the breaststroke cycle movement of the arms and legs was divided into two phases: propulsive or non-propulsive. In addition, indices characterizing the temporal coordination of movements of the upper limbs in relation to the lower limbs were distinguished: 1) Arm-Leg Lag - determines the interval between the phases of propulsion generated by upper and lower limbs; 2) Glide or Overlap - the inter-cyclic glide or overlap of the propulsive movement of the upper on lower limbs. Significant dependence was noted between the swim speed (V50surface breast) and the percentage of time of the arm propulsive in-sweep phase 0.64, p < 0.01. A significant correlation was observed between the V50surface breast with the percentage of partially surfaced hand phase of arm recovery 0.54, p < 0.01. Correlation between total leg propulsion and non-propulsion phases with V50surface breast was 0.49 and -0.49 respectively, both p < 0.01. The Glide or Overlap index was significantly related to the swimming speed V50surface breast 0.48, p < 0.05. This type of analysis suggests how to refine the swimming technique, with the goal to improve the current speed capabilities; furthermore the results also indicate the direction of its development in the future swimmers of the group studied. Key PointsThis study investigated the influence of the inter- and intra-cyclic time structure of the movements in sprint breaststroke swimming.The distinction of the operations phases of the upper limbs in the propulsive movement shows significant correlation 0.64, p <0.01 between the swimming speed V50surface breast and the execution time of the in-sweep phase in the movement cycle. Significant relationship was noted between minimizing the first non-propulsive phase of arm recovery with higher contribution of the next, partially immersed sliding phase of arm recovery.The specification of the inter-cyclic coordination index of the upper and lower limbs during the movement cycle shows influence of the overlap of the propulsive movement of the upper limbs on the propulsive movement of the lower limbs on V50surface breast with correlation 0.48, p <0.05 for young swimmers.

Swimming speed of the breaststroke kick.

The breaststroke kick is responsible for a considerable portion of the forward propulsion in breaststroke swimming. The aim of this study was to measure selected anthropometric variables and functional properties of a swimmer's body: length of body parts; functional range of motion in the leg joints and anaerobic power of the lower limbs. Chosen kinematic variables useful in the evaluation of swimming performance in the breaststroke kick were evaluated. In the present research, swimming speed using breaststroke kicks depended to the largest extent on anaerobic endurance (0.46, p < 0.05 partial correlations with age control). In addition, knee external rotation and swimming technique index had an impact on swimming speed and kick length (both partial correlations with age control 0.35, p < 0.08). A kinematic analysis of the breaststroke kick hip displacement compatible with horizontal body displacement was significantly negatively correlated with foot slip in the water opposite to body displacement (partial correlations: with leg length control -0.43, p < 0.05; with shank length control -0.45, p < 0.05, respectively). Present research and measurements of selected body properties, physical endurance and kinematic movement analysis may help in making a precise determination of an athlete's talent for breaststroke swimming.