Acute effects of dryland muscular endurance and maximum strength training on sprint swimming performance in young swimmers.

The study examined acute effects of dryland muscular endurance (ME) and maximum strength (MS) sessions on performance, physiological, and biomechanical variables during a subsequent sprint swimming session. Twenty-seven swimmers (16.5 ± 2.6 yrs) completed three experimental conditions including: i) ME, 55% of 1-repetition maximum, ii) MS, 90% of 1-repetition maximum, and iii) control (CON, no dry-land). Twenty minutes following ME, MS and CON sessions swimmers performed a 10-s tethered swimming sprint, four by 50-m (4 × 50-m), and a 100-m front crawl sprints. Performance time, blood lactate, heart rate (HR), stroke rate (SR), stroke length (SL), stroke index (SI), and stroke efficiency (ηF) were measured during 4 × 50-m and 100-m. Hand grip strength (HG), and shoulder muscles isometric strength (ISO) were measured after each session. Mean 4 × 50-m time increased in ME compared to CON by 1.7 ± 2.7% (p = 0.01), while 100-m time was similar among conditions (p > 0.05). ISO was lower after dry-land training in all conditions (p = 0.01). Tethered force, HG, HR, SR, SL, SI, and ηF were no different between conditions (p > 0.05). Dryland ME session decrease swimming performance; however, ME and MS sessions did not affect technical ability during a subsequent maximum intensity swimming.

Studying Respiratory Symptoms Related to Swimming Pools Attendance in Young Athletes: The SPHeRA Study.

This study investigates the prevalence of respiratory symptoms and the training factors possibly associated with them in a sample of young Italian competitive swimmers. A questionnaire about training information and symptoms was administered to participants during the winter and summer 2021 training seasons. In total, 396 athletes took part in the study. In the winter training subgroup (n = 197), we found significant associations between increasing training hours per session and the presence of nasal congestion/rhinorrhoea (OR = 3.10; p = 0.039) and cough (OR = 3.48; p = 0.015). Total training hours per week were significantly associated with nasal congestion/rhinorrhoea (OR = 1.12; p = 0.010). In the summer group (n = 199), the same factors were not associated with respiratory symptoms. Having an allergy was significantly related to nasal congestion/rhinorrhea in both the logistic models (model 1 OR = 2.69, p = 0.013; model 2 OR = 2.70, p = 0.012), while having asthma significantly increased the risk of coughing (OR = 3.24, p = 0.033). The kind of environment (indoor or outdoor facilities) did not affect the studied symptoms either in summer or winter. Further investigations are needed to better understand the mechanisms involved in the development of respiratory symptoms in swimmers, particularly on how inflammation and remodelling develop and which environmental conditions can favour these processes.

Kinematics and physiological parameters in maximal swimming tests in age-group swimmers / Cinemática y parámetros fisiológicos en pruebas de natación máxima en nadadores de grupos de edad

Objective: The aim of this study was compared and correlate kinematics and physiological parameters in four maximal swimming tests of two groups of young swimmers.Methods: Twelve swimmers, separated in two groups by age (percentile > 50th (n = 6): 15.4 ± 1.11 years old as group 1, and < 50th (n = 6): 12.1 ± 0.83 as group 2) performed four tests during two different sessions. . They performed front crawl trials at maximum intensity: 50 and 200 meters on first day and 100 and 400 m meters on second day. Anthropometric characteristics were measured. Stroke rate, stroke length, stroke index, swimming speed and critical speed were obtained by video analysis. Moreover, were measured the blood lactate concentration, heart rate and rate of perceived exertion.Results: There are no differences at anthropometric characteristics. We found difference between group 1 and group 2. Better results for performance, swimming speed, stroke length and stroke index in group 1. Swimming speed and stroke index show strong correlation in all tests for group 1 and in 50 and 100 meters for group 2. To measure the swimmer profile is essential to verify the benefits that the training program is or is not providing.Conclusion: The parameters evaluated seem related to age and capacities of the swimmers.(AU)

Functional Movement Screen evaluation: comparison between elite and non-elite young swimmers / Evaluación Functional Movement Screen: Comparación entre nadadores jóvenes de élite y no élite

Functional Movement Screen®(FMS®) allows to assess athlete’s movement functionality. Movement funcionality in young elite and non-elite swimmers may predict future performance. The purpose of this study is to compare FMS®scores between young elite and non-elite swimmers, and to verify their relationship with 100m freestyle performance. Thirty-two elite swimmers (age: 14.99 ± 0.13 years old; height: 1.71 ± 0.02 m; body mass: 61.28 ± 1.27 kg; Fédération Internationale de Natation [FINA] points: 651.59 ± 6.44) and 17 non-elite swimmers (age: 14.65 ± 0.19 years old; height: 165.12 ± 2.03 cm; body mass: 57.22 ± 2.43 kg; FINA points: 405.71 ± 21.41) volunteered to participate in this cross-sectional study. Individual-test FMS®scores, FMS®composite score and FINA points were considered for analysis.Elite swimmers achieved higher Deep Squat (p= 0.005; ES = 0.99), Right Hurdle Step (p= 0.005; ES = 0.99), Left Hurdle Step (p= 0.002; ES = 1.08), Trunk Stability Push Up (p< 0.001; ES = 1.44) and FMS®composite (p< 0.001; ES = 1.35) scores compared to non-elite swimmers. FMS®composite scores were positively related with 100m freestyle performance (r = 0.596, r2= 40.9%, p< 0.001).Young non-elite swimmers reveal functional deficits in tasks involving mobility of the hips,knees and ankles, and stabilization of the core and spine. Higher movement functionality is positively related with 100m freestyle performance. Swimming coaches should consider these deficits and their relationship with performance to differentiate exercise prescription between this populations. (AU)

O Functional Movement Screen®(FMS®) permite avaliar a funcionalidade do movimento em atletas. A funcionalidade do movimento em jovens nadadores de elite e não-elite pode prever o desempenho futuro. O objetivo deste estudo é comparar os scores do FMS® entre jovens nadadores de elite e não-elite e verificar sua relação com o desempenho de 100m no estilo livre. Trinta e dois nadadores de elite (idade: 14,99 ± 0,13 anos; altura: 1,71 ± 0,02 m; massa corporal: 61,28 ± 1,27 kg; Fédération Internationale de Natation [FINA] pontos: 651,59 ± 6,44) e17 nadadores não-elite (idade: 14,65 ± 0,19 anos; altura: 165,12 ± 2,03 cm; massa corporal: 57,22 ± 2,43 kg; pontos FINA: 405,71 ± 21,41) que se voluntariaram para participar neste estudo transversal. ScoresFMS® de teste individual, scorescompostosFMS®e pontos FINA foram considerados para análise. Nadadores de elite alcançaram valores mais elevados no Deep Squat(p = 0,005; ES = 0,99), Right Hurdle Step(p= 0,005; ES = 0,99),Left Hurdle Step(p= 0,002; ES = 1,08), Trunk Stability Push Up(p< 0,001); ES = 1,44) e FMS®compostos (p< 0,001; ES = 1,35) em comparação com nadadores não elite. Os scorescompostos do FMS®foram positivamente relacionados com o desempenho de 100m no estilo livre (r = 0,596, r2= 40,9%, p< 0,001). Jovens nadadores do grupo não-elite revelam défices funcionais em tarefas que envolvem mobilidade das ancas, joelhos e tornozelos e estabilização do núcleo e da coluna. A maior funcionalidade de movimento está positivamente relacionada ao desempenho de 100m estilo livre. Os treinadores de natação devem considerar esses défices e sua relação com o desempenho para diferenciar a prescrição de exercícios entre essas populações. (AU)

Acute Resistance Exercise: Physiological and Biomechanical Alterations During a Subsequent Swim Training Session.

PURPOSE: To examine the acute effect of dry-land strength training on physiological and biomechanical parameters in a subsequent swim training session. METHODS: Twelve male swimmers (age: 19.0 [2.2] y, peak oxygen uptake: 65.5 [11.4] mL·kg-1·min-1) performed a 5 × 200-m test with progressively increasing intensity. Blood lactate (BL) concentration was measured after each 200-m bout, and the speed corresponding to 4 mmol·L-1 (V4) was calculated. In the experimental (EXP) and control (CON) conditions, swimmers participated in a swim training session consisting of 1000-m warm-up, a bout of 10-second tethered swimming sprint, and 5 × 400 m at V4. In EXP condition, swimmers completed a dry-land strength training session (load: 85% of 1-repetition maximum) 15 minutes before the swimming session. In CON condition, swimmers performed the swimming session only. Oxygen uptake, BL concentration, arm-stroke rate, arm-stroke length, and arm-stroke efficiency were measured during the 5 × 400 m. RESULTS: Force in the 10-second sprint was not different between conditions (P = .61), but fatigue index was higher in the EXP condition (P = .03). BL concentration was higher in EXP condition and showed large effect size at the fifth 400-m repetition compared with CON condition (6.4 [2.7] vs 4.6 [2.8] mmol·L-1, d = 0.63). During the 5 × 400 m, arm-stroke efficiency remained unchanged, arm-stroke length was decreased from the third repetition onward (P = .01), and arm-stroke rate showed a medium increment in EXP condition (d = 0.23). CONCLUSIONS: Strength training completed 15 minutes before a swim training session caused moderate changes in biomechanical parameters and increased BL concentration during swimming. Despite these changes, swimmers were able to maintain force and submaximal speed during the endurance training session.

Sensorimotor control and neuromuscular activity of the shoulder in adolescent competitive swimmers with generalized joint hypermobility.

INTRODUCTION: Shoulder pain is highly prevalent in competitive swimmers, and generalized joint hypermobility (GJH) is considered a risk factor. Sensorimotor control deficiencies and altered neuromuscular activation of the shoulder may represent underlying factors. RESEARCH QUESTION: To investigate whether competitive swimmers with GJH including shoulder hypermobility (GJHS) differ in shoulder sensorimotor control and muscle activity from those without GJH and no shoulder hypermobility (NGJH). METHODS: Competitive swimmers (aged 13-17) were recruited. GJHS or NGJH status was determined using the Beighton score (0-9) and Rotès-Quérol test (positive/negative). Inclusion criteria for GJHS were a Beighton score ≥5 and minimum one hypermobile shoulder, while NGJH was defined as a Beighton score ≤3 and no shoulder hypermobility. Three prone lying, upper-extremity weight-bearing shoulder stabilometric tests were performed on a force platform: Bilateral upper-extremity support eyes open (BL-EO) and eyes closed (BL-EC) and unilateral upper-extremity support eyes open (UL-EO). Surface electromyography (SEMG) was measured from the upper trapezius, lower trapezius, serratus anterior, infraspinatus and pectoralis major muscles. SEMG was normalized using maximal voluntary isometric contractions and presented relative to maximal voluntary SEMG (%MVE). Co-contraction index (CCI) was calculated for the following muscle pairs: upper trapezius-lower trapezius, upper trapezius-serratus anterior, and infraspinatus-pectoralis major. Between-group differences in stabilometric parameters, %MVE, and CCI were analyzed with a mixed effects model. RESULTS: Thirty-eight swimmers were enrolled as GJHS (n = 19) or NGJH (n = 19). There were no group differences in stabilometric parameters or CCI. GJHS displayed significantly decreased (29%) pectoralis major activity during BL-EO compared to NGJH (5.35 ±â€¯1.77%MVE vs. 7.51 ±â€¯1.96%MVE; p = 0.043). SIGNIFICANCE: Adolescent competitive swimmers with GJHS displayed no shoulder sensorimotor control deficiencies and no generally altered shoulder muscle activity pattern, except for decreased pectoralis major activity in BL-EO. Longitudinal studies are needed to investigate whether decreased pectoralis major activation contributes to the development of shoulder pain in swimmers with GJHS.

Systemic and airway oxidative stress in competitive swimmers.

BACKGROUND: The environment in swimming pools, which contain chlorine, might interact with the airway epithelium, resulting in oxidative stress and/or inflammation during high intensity training periods. METHODS: We evaluated pulmonary functional (metacholine challenge test, FEV1 and VC), cellular (eosinophils and neutrophils), inflammatory (FeNo, IL-5, IL-6, IL-8 and TNF-α), oxidative (8-isoprostanes) and angiogenesis factors (VEGF) in induced sputum and peripheral blood of 41 healthy non-asthmatic elite swimmers (median 16 years) during the period of high intensity training before a national championship. The second paired sampling was performed seven months later after training had been stopped for one month. RESULTS: There was a ten-fold increase (median 82-924 pg/ml; P < 0.001) in 8-isoprostanes in induced sputum and five-fold increase (median 82-924 pg/ml; P < 0.001) in sera during training in comparison to the period of rest. However, there was no difference in FEV1 (113 vs 116%), VC (119 vs 118%), FeNo (median 34 vs 38 ppb), eosinophils (2.7 vs 2.9% in sputum; 180 vs 165 cells/µl in blood), neutrophils, different cytokines or VEGF in induced sputum or sera. The only exception was TNF-α, which was moderately increased in sera (median 23 vs 40 pg/ml; P = 0.02) during the peak training period. Almost half (18 of 41) of swimmers showed bronchial hyperresponsiveness during the peak training period (PC20 cutoff was 4 mg/ml). There was no correlation between hyperresponsiveness and the markers of oxidative stress or inflammation. CONCLUSIONS: High intensity training in healthy, non-asthmatic competitive swimmers results in marked oxidative stress at the airway and systemic levels, but does not lead to airway inflammation. However, we could not confirm that oxidative stress is associated with bronchial hyperresponsiveness (AHR), which is often observed during the peak exercise training period.

Efficacy of intermittent hypoxic training on hemodynamic function and exercise performance in competitive swimmers.

PURPOSE: Hemodynamic function is a parameter indicating oxygen delivery and utilization capacity and is an important determinant of exercise performance. The present study aimed to determine whether intermittent hypoxic training (IHT) ameliorates hemodynamic function and exercise performance in competitive swimmers. METHODS: Twenty competitive swimmers (10 men, 10 women) volunteered to participate in the study. Participants were divided into the normoxic training (NT) group and the hypoxic training (HT) group and were subjected to training in a simulated altitude of 3000 m. We evaluated hemodynamic function profiles over 30 min of submaximal exercise on a bicycle and exercise performance before and after 6 weeks of training, which involved continuous exercise at 80% maximal heart rate (HRmax) for 30 min and interval exercise at 90% of HRmax measured before training for 30 min (ten rounds comprising 2 min of exercise followed by 1 min of rest each round). RESULTS: Significant changes in oxygen consumption (decrease) and end-diastolic volume (increase) were observed only in the HT group. Heart rate (HR), cardiac output (CO), and ejection fraction (EF) were significantly reduced in both groups, but the reduction rates of HR and CO were greater in the HT group than in the NT group. Exercise performance measures, including maximal oxygen consumption and 400-m time trial, were significantly increased only in the HT group. CONCLUSION: Our findings suggested that 6 weeks of IHT, which involved high-intensity continuous and interval exercise, can effectively improve exercise performance by enhancing hemodynamic function in competitive swimmers.

Morning Exercise: Enhancement of Afternoon Sprint-Swimming Performance.

CONTEXT: An exercise bout completed several hours prior to an event may improve competitive performance later that same day. PURPOSE: To examine the influence of morning exercise on afternoon sprint-swimming performance. METHODS: Thirteen competitive swimmers (7 male, mean age 19 ± 3 y; 6 female, mean age 17 ± 3 y) completed a morning session of 1200 m of variedintensity swimming (SwimOnly), a combination of varied-intensity swimming and a resistance-exercise routine (SwimDry), or no morning exercise (NoEx). After a 6-h break, swimmers completed a 100-m time trial. RESULTS: Time-trial performance was faster in SwimOnly (1.6% ± 0.6, mean ± 90% confidence limit, P < .01) and SwimDry (1.7% ± 0.7%, P < .01) than in NoEx. Split times for the 25- to 50-m distance were faster in both SwimOnly (1.7% ± 1.2%, P = .02) and SwimDry (1.5% ± 0.8%, P = .01) than in NoEx. The first 50-m stroke rate was higher in SwimOnly (0.70 ± 0.21 Hz, mean ± SD, P = .03) and SwimDry (0.69 ± 0.18 Hz, P = .05) than in NoEx (0.64 ± 0.16 Hz). Before the afternoon session, core (0.2°C ± 0.1°C [mean ± 90% confidence limit], P = .04), body (0.2°C ± 0.1°C, P = .02), and skin temperatures (0.3°C ± 0.3°C, P = .02) were higher in SwimDry than in NoEx. CONCLUSIONS: Completion of a morning swimming session alone or together with resistance exercise can substantially enhance sprint-swimming performance completed later the same day.

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.

The association between generalized joint hypermobility and active horizontal shoulder abduction in 10-15 year old competitive swimmers.

BACKGROUND: Increased shoulder mobility and Generalised Joint Hypermobility (GJH) are assumed to be predisposing risk factors for shoulder injuries. The association between GJH and shoulder mobility among competitive swimmers is unknown. The aim was to study the association between GJH and active horizontal shoulder abduction (AHSA) in young, competitive swimmers and to describe normative values of AHSA in this group. METHODS: In total, 92 swimmers (10-15 years) without shoulder pain participated. GJH was evaluated with the Beighton Tests (BT) for joint hypermobility. Shoulder mobility was measured as maximum AHSA. A multiple regression model was used to assess associations between GJH and AHSA. RESULTS: Overall, positive associations were found between GJH and AHSA. An increase of BT score was associated with an increase of AHSA, seen as an increased AHSA of 3.9°, 5.7° and 7.9° by BT cut off points ≥5/9, ≥6/9 and ≥7/9, respectively. Normative values for AHSA ranged from 40° to 52°, depending on age. CONCLUSIONS: Positive associations were found between GJH and AHSA, as maximum AHSA range increased with increasing BT scores. Due to lack of shoulder mobility tests in the BT scoring system, the AHSA test seems to be a promising supplemental test.

Combined inhalation of beta2 -agonists improves swim ergometer sprint performance but not high-intensity swim performance.

There is a high prevalence of asthma and airway hyperresponsiveness (AHR) in elite athletes, which leads to a major use of beta2 -agonists. In a randomized double-blinded crossover study, we investigated the effects of combined inhalation of beta2 -agonists (salbutamol, formoterol, and salmeterol), in permitted doses within the World Anti-Doping Agency 2013 prohibited list, in elite swimmers with (AHR, n = 13) or without (non-AHR, n = 17) AHR. Maximal voluntary isometric contraction of m. quadriceps (MVC), sprint performance on a swim ergometer and performance in an exhaustive swim test at 110% of VO2max were determined. Venous plasma interleukin-6 (IL-6) and interleukin-8 (IL-8) were measured post-exercise. No improvement was observed in the exhaustive swim test, but swim ergometer sprint time was improved (P < 0.05) in both groups from 57 ± 1.7 to 56 ± 1.8 s in AHR and 58.3 ± 1 to 57.4 ± 1 s in non-AHR. MVC and post-exercise plasma IL-6 increased (P < 0.05) with beta2 -agonists in both groups, whereas IL-8 only increased in AHR. In summary, inhalation of beta2 -agonists, in permitted doses, did not improve swim performance in elite swimmers. However, swim ergometer sprint performance and MVC were increased, which should be considered when making future anti-doping regulations.