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The objective of this research was to compare technical skills composed of kinematic and kinetic variables in the complex motor task of a tumble turn between 9 elites and 9 sub-elite female swimmers. The best tumble turn among three attempts was analyzed using a three-dimensional underwater protocol. A total of 37 kinematic variables were derived from a Direct Linear Transformation algorithm for 3D reconstruction, and 16 kinetic variables measured by a piezoelectric 3D force platform. Data were analyzed by Student's t-test and effect size statistics. Pearson correlations were applied to the data of the eighteen swimmers to relate the association of 53 kinematic, kinetic variables to the performance of the tumble-turn (3 meters Round Trip Time, 3m RTT). The approach and the whole turn times were faster for elite swimmers compared to sub elites (1.09±0.06 vs. 1.23±0.08 sec, and 2.89±0.07 vs. 3.15±0.11 sec.), as well as the horizontal speeds of the swimmers' head 1 m before the rotation (1.73±0.13 vs. 1.57±0.13 m/sec.), at the end of the push-off on force platform (2.55±0.15 vs. 2.31±0.22 m/sec.) and 3 m after the wall (2.01±0.19 vs. 1.68±0.12 m/sec.). Large differences (|d| > 0.8) in favor of the elite swimmers were identified for the index of upper body extension at the beginning of the push-off, the lower limb extension index at the end of push-off, and among the kinetic variables, the horizontal impulse and lateralization of the push-off. Correlations for the whole group revealed a moderate to strong relationship between 6 body extension indices and 3mRTT performance. For the kinetic variables, the correlations indicated the fastest swimmers in 3mRTT showed large lateral impulse during placement (r=0.46), maximum horizontal force during the push-off (r=0.45) and lateralization of the push-off (r=0.44) (all p<0.05). Elite female swimmers had higher approach and push-off speeds, were more streamlined through the contact, and showed a higher horizontal impulse and lateralization of the push-off, than their sub-elite counterparts.
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Algoritmos , Extremidad Inferior , Humanos , Femenino , Cinética , RotaciónRESUMEN
The objective was to compare the metabolic responses of high-level national swimmers to threshold or polarised training. 22 swimmers (n = 12 males and 10 females) participated in a 28-week cross-over intervention study consisting of 2 × 6 period weeks of training. Swimmers were assigned randomly to either training group for the first period: polarised (POL) (81% in energetic zone 1: blood lactate [La]b ≤ 2 mmol.L-1; 4% in zone 2: 2 mmol.L-1 <[La]b ≤ 4 mmol.L-1; 15% in zone 3: [La]b > 4 mmol.L-1) or threshold (THR) (65%/25%/10%). Before and after each training period, urine samples were collected for non-targeted metabolomics analysis. Mixed model analysis was performed on metabolomics data including fatigue class factors and/or training and/or interaction. Ion intensities of 6-keto-decanoylcarnitine (+31%), pregnanediol-3-glucuronide (+81%), P-cresol sulphate (+18%) were higher in the threshold group (P < 0.05) indicating higher glycogenic depletion and inflammation without alteration of the neuroendocrine stress axis. 4-phenylbutanic acid sulphate was 200% higher in less fatigued swimmers (P < 0.01) linking the anti-inflammatory activity at the cell membrane level to the subjective perception of fatigue. This research suggests the importance of replenishing glycogen stores and reducing inflammation during high thresholds training loads.
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Atletas , Fatiga/orina , Espectrometría de Masas/métodos , Estrés Fisiológico , Natación , Adolescente , Ácido Butírico/orina , Carnitina/análogos & derivados , Carnitina/orina , Cresoles/orina , Estudios Cruzados , Femenino , Glucógeno/metabolismo , Humanos , Inflamación/metabolismo , Ácido Láctico/sangre , Masculino , Metabolómica , Concentración Osmolar , Pregnanodiol/análogos & derivados , Pregnanodiol/orina , Distribución Aleatoria , Ésteres del Ácido Sulfúrico/orinaRESUMEN
This study investigated the effects of gender and the manipulation of the preferred stroke rate on swimming performance and arm coordination in elite front crawl swimmers. Nineteen swimmers performed a dual task, that is, imposed stroke rate and maximal speed. They swam nine 25-m trials at maximal speed twice: one trial at the preferential stroke rate, one trial at maximal stroke rate and seven trials at stroke rates between 41 and 59 cycles/min imposed by an Aquapacer. Stroke rate, arm stroke phases, and arm coordination were computed from an inertial measurement unit on each forearm and one on the sacrum. Time on the 25-m was recorded to assess swimming speed. Results indicated that the error between the imposed and performed stroke rates was lowest at the preferred stroke rate for women. An increase in stroke rate led to an increase in swimming speed and the index of coordination, but these changes could be influenced by the preferred stroke rate. Individual analysis revealed that some swimmers exhibited higher flexibility (larger range of stroke rate) around their preferred stroke rate. This stroke rate flexibility appeared more functional in swimmers who reached higher speeds when swimming at the maximal stroke rate than at the preferred stroke rate.
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Brazo/fisiología , Rendimiento Atlético/fisiología , Destreza Motora/fisiología , Natación/fisiología , Aceleración , Fenómenos Biomecánicos , Conducta Competitiva/fisiología , Femenino , Humanos , Modelos Lineales , Masculino , Factores Sexuales , Adulto JovenRESUMEN
This case study reports the training of an elite 25-km open-water swimmer and the daily heart rate variability (HRV) changes during the 19-week period leading to his world champion title. Training load was collected every day and resting HRV was recorded every morning. The swimmer's characteristics were VÌO2max: 58.5 ml·min-1·kg-1, maximal heart rate: 178 beats per minute, and maximal ventilation: 170 L·min-1. Weekly training volume was 85±21 km, 39±8% was at [La]b<2 mmol · L-1 (Z1), 53±8% was at [La]b 2-4 mmol·L-1 (Z2), and 8±4% was at [La]b>4 mmol·L-1 (Z3). In the supine position, the increase in training volume and Z2 training were related to increases in rMSSD and HF. In the standing position, an increase in parasympathetic activity and decrease in sympathetic activity were observed when Z1 training increased. Seasonal changes indicated higher values in the LF/HF ratio during taper, whereas higher values in parasympathetic indices were observed in heavy workload periods. This study reports extreme load of an elite ultra-endurance swimmer. Improvements in parasympathetic indices with increasing Z2 volume indicate that this training zone was useful to improve cardiac autonomic activity, whereas Z1 training reduced sympathetic activity.
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Frecuencia Cardíaca , Acondicionamiento Físico Humano/métodos , Resistencia Física/fisiología , Natación/fisiología , Humanos , Ácido Láctico/sangre , Masculino , Consumo de Oxígeno , Sistema Nervioso Parasimpático/fisiología , Frecuencia Respiratoria , Posición de Pie , Posición Supina , Sistema Nervioso Simpático/fisiología , Adulto JovenRESUMEN
To study the variability in stroking parameters between and within laps and individuals during competitions, we compared and modeled the changes of speed, stroke rate, and stroke length in 32 top-level male and female swimmers over 4 laps (L1-L4) in 200-m freestyle events using video-derived 2-dimensional direct linear transformation. For the whole group, speed was greater in L1, with significant decreases across L2, L3, and L4 (1.80 ± 0.10 vs 1.73 ± 0.08; 1.69 ± 0.09; 1.66 ± 0.09 · s-1, P < .05). This variability was attributed to a decrease in stroke length (L2: 2.43 ± 0.19 vs L4: 2.20 ± 0.13 m, P < .05) and an increase in stroke rate (L2: 42.8 ± 2.6 vs L4: 45.4 ± 2.3 stroke · min-1, P < .05). The coefficient of variation and the biological coefficient of variation in speed were greater for male versus female (3.9 ± 0.7 vs 3.1 ± 0.7; 2.9 ± 1.0 vs 2.6 ± 0.7, P < .05) and higher in L1 versus L2 (3.9 ± 1.3 vs 3.1 ± 0.1; 2.9 ± 0.9 vs 2.3 ± 0.7, P < .05). Intra-lap speed values were best represented by a cubic (n = 38), then linear (n = 37) and quadratic model (n = 8). The cubic fit was more frequent for males (43.8%) than females (15.6%), suggesting greater capacity to generate higher acceleration after the turn. The various stroking parameters managements within lap suggest that each swimmer adapts his/her behavior to the race constraints.
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Adaptación Fisiológica , Rendimiento Atlético/fisiología , Conducta Competitiva/fisiología , Movimiento/fisiología , Natación/fisiología , Adulto , Fenómenos Biomecánicos/fisiología , Femenino , Humanos , Masculino , Reproducibilidad de los Resultados , Grabación en VideoRESUMEN
To investigate associations between a swimmer's career progression and winning a medal at the Olympic Games (OG) or World Championships (WC). A total of 4631 swimming performances of 1535 top swimmers (653 women, 882 men) from 105 nationalities since1973 were extracted from FINA rankings. A panel of 12 predictor variables including nationality, gender, competition, age, number and timing of competitions, pattern of progressions and regressions in performance, and medal outcomes was established. Linear logistic regression was used to study the association between winning a medal and predictor variables. Logistic regression coefficients were obtained by training on 80% of the database, and prediction accuracy evaluated on the remaining 20%. Using the training set, a selection of 9 most relevant features for prediction of winning a medal (target variable) was obtained through exhaustive feature selection and cross-validation: nationality, competition, number of competitions, number of annual career progressions (nb_prog), maximum annual career progression (max-progr), number of annual career regressions (nb_reg), age at maximum annual progression, P6 (the level of performance six months before the World Championships or Olympic Games), and P2 (the level of performance two months before the World Championships or Olympic Games). A logistic regression model was built and retrained on the entire training set achieved an area under the ROC curve of ~90% on the test set. The odds of winning a medal increased by 1.64 (95% CI, 1.39-1.91) and 1.44 (1.22-1.72) for each unit of increase in max-progr and n-prog, respectively. Odds of winning a medal decreased by 0.60 (0.49-0.72) for a unit increase in n-reg. In contrast, the odds increased by 1.70 (1.39-2.07) and 4.35 (3.48-5.42) for improvements in the 6 and 2 months before competition (P<0.001, for all variables). The likelihood of a swimmer winning an international medal is improved by ~40-90% with progressions from season-to-season, and reducing the number of regressions in performance. The chances of success are also improved 2- to 4-fold by substantial improvements in performance in the months before competition.
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Rendimiento Atlético , Natación , Humanos , Natación/fisiología , Masculino , Femenino , Rendimiento Atlético/fisiología , Distinciones y Premios , Adulto , Modelos Logísticos , Conducta Competitiva/fisiología , AtletasRESUMEN
The underwater phase of starts represents an important part of the performance in sprint swimming's events. Kinematics variables that swimmers have to take into account to improve their underwater phase of starts are unknown. The aim of this study was to determine the kinematics variables that improve performance during the underwater phase of grab starts. A three-dimensional analysis of the underwater phase of ten swimmers of national level was conducted. Stepwise multiple linear regressions identified the main kinematics variables that influence the horizontal velocity of the swimmer each 0.5 m in the range of 5 to 7.5 m. The results show that the kinematics parameters change during the range of 5 to 7.5 m of the underwater phase of the starts. For this population of swimmers, the results enable proposals of four principles to improve the underwater phase: i) to be streamlined at the beginning of the underwater gliding phase, ii) to start the dolphin kicking after 6 m, iii) to generate propulsive forces using only feet and legs during underwater undulatory swimming, iv) to improve the frequency of underwater undulatory swimming.
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Inmersión/fisiopatología , Pierna/fisiología , Modelos Biológicos , Esfuerzo Físico/fisiología , Reología/métodos , Natación/fisiología , Simulación por Computador , Femenino , Humanos , Adulto JovenRESUMEN
The aim of this exploratory study was to identify the most influential training designs during the final six weeks of training (F6T) before a major swimming event, taking into account athletes' evolution over several seasons. Fifteen female and 17 male elite swimmers were followed for one to nine F6T periods. The F6T was divided into two sub-periods of a three-week overload period (OP) and a three-week taper period (TP). The final time trial performance was recorded for each swimmer in his or her specialty at the end of both OP and TP. The change in performances (ΔP) between OP and TP was recorded. Training variables were derived from the weekly training volume at several intensity levels as a percentage of the individual maximal volume measured at each intensity level, and the individual total training load (TTL) was considered to be the mean of the loads at these seven intensity levels. Also, training patterns were identified from TTL in the three weeks of both OP and TP by cluster analysis. Mixed-model was used to analyse the longitudinal data. The training pattern during OP that was associated with the greatest improvement in performance was a training load peak followed by a linear slow decay (84 ± 17, 81 ± 22, and 80 ± 19 % of the maximal training load measured throughout the F6T period for each subject, Mean ± SD) (p < 0.05). During TP, a training load peak in the 1(st) week associated with a slow decay design (57 ± 26, 45 ± 24 and 38 ± 14%) led to higher ΔP (p < 0.05). From the 1(st) to 3(rd) season, the best results were characterized by maintenance of a medium training load from OP to TP. Progressively from the 4(th) season, high training loads during OP followed by a sharp decrease during TP were associated with higher ΔP. Key PointsDuring the overload training period, a medium training load peak in the first week followed by an exponential slow decay training load design was linked to highest performance improvement.During the taper period, a training load peak in the first week associated with a slow decay design led to higher performances.Over the course of the swimmers' athletic careers, better performances were obtained with an increase in training load during the overload period followed by a sharper decrease in the taper period.Training loads schedules during the final six weeks of training before a major swimming event and changes over time could be prescribed on the basis of the model results.
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Based on a three-dimensional (3D) underwater analysis, the objective of the present study was to identify the biomechanical variables the most associated with turn times in 10 elite female swimmers. For each participant (95.7 ± 2.6% of the 200 m freestyle world record), the best-time turn (from 3 m in to 3 m out, 2.89 ± 0.08 s) was analysed from a three-dimensional (3D) direct linear transformation kinematical reconstruction and the use of a piezoelectric force platform. Bivariate analysis showed that lateral impulse was linked to turn time (r = -0.76, p = 0.01) as well as horizontal velocities at end of the glide and swim resumption (respectively, 1.88 ± 0.2 m·s-1 and 1.48 ± 0.15 m·s-1; r = -0.67 and -0.68; p < 0.05 for both variables). One variable was considered relevant in the best Lasso (Least Absolute Shrinkage and Selection Operator) model: the lateral impulse (8.8 ± 5.1 N·s) during the placement sub-phase.The best tumble turn times were associated with higher lateral impulse during the placement and faster velocities during the underwater actions. The lateral impulse may reflect the swimmers' longitudinal rotation which was higher for the fastest swimmers.
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Natación , Humanos , Femenino , Fenómenos BiomecánicosRESUMEN
PURPOSE: To quantify the impact of successive competitions on swimming performance in world-class swimmers. METHODS: An entire data set of all events swum during a new competition named the International Swimming League was collected. A Bayesian linear mixed model has been proposed to evaluate whether a progression could be observed during the International Swimming League's successive competitions and to quantify this effect according to event, age, and gender. RESULTS: An overall progression of 0.0005 (0.0001 to 0.0010) m/s/d was observed. The daily mean progression (ie, faster performance) was twice as high for men as for women (0.0008 [0.00 to 0.0014] vs 0.0003 [-0.0003 to 0.0009] m·s-1). A tendency toward higher progression for middle distances (200 and 400 m) and for swimmers of a higher caliber (above 850 FINA [Fédération Internationale de Natation] points) was also observed. Swimmers between 23 and 26 years of age seemed to improve their swimming speed more in comparison with the other swimmers. CONCLUSIONS: This new league format, which involves several competitions in a row, seems to allow for an enhancement in swimming performance. Coaches and their support staff can now adapt their periodization plan in order to promote competition participation.
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Rendimiento Atlético , Natación , Adaptación Fisiológica , Teorema de Bayes , Femenino , Humanos , Modelos Lineales , MasculinoRESUMEN
BACKGROUND: This study investigated the periodization of elite swimmers' training over the 25 weeks preceding the major competition of the season. METHODS: We conducted a retrospective observational study of elite male (n = 60) and female (n = 67) swimmers (46 sprint, 81 middle-distance) over 20 competitive seasons (1992-2012). The following variables were monitored: training corresponding to blood lactate <2 mmolâ L-1, 2 to ≤4 mmolâ L-1, >4-6 mmolâ L-1, >6 mmolâ L-1, and maximal swimming speed; general conditioning and maximal strength training hours; total training load (TTL); and the mean normalized volumes for both in-water and dryland workouts. Latent class mixed modeling was used to identify various TTL pattern groups. The associations between pattern groups and sex, age, competition event, Olympic quadrennial year, training contents, and relative performance were quantified. RESULTS: For the entire cohort, â¼86-90% of the training was swum at an intensity of [La]b ≤ 4 mmolâ L-1. This training volume was divided into 40-44% at <2 mmolâ L-1 and 44-46% at 2 to ≤4 mmolâ L-1, leaving 6-9.5% at >4-6 mmolâ L-1, and 3.5-4.5% at >6 mmolâ L-1. Three sprint TTL patterns were identified: a pattern with two long â¼14-15-week macrocycles, one with two â¼12-13 week macrocycles each composed of a balanced training load, and one with a single stable flat macrocycle. The long pattern elicited the fastest performances and was most prevalent in Olympic quadrennials (i.e., 4 seasons preceding the 2004, 2008, and 2012 Olympic Games). This pattern exhibited moderate week-to-week TTL variability (6 ± 3%), progressive training load increases between macrocycles, and more training at ≤4 mmolâ L-1 and >6 mmolâ L-1. This fastest sprint pattern showed a waveform in the second macrocycle consisting of two progressive load peaks 10-11 and 4-6 weeks before competition. The stable flat pattern was the slowest and showed low TTL variability (4 ± 3%), training load decreases between macrocycles (P < 0.01), and more training at 4-6 mmolâ L-1 (P < 0.01). CONCLUSION: Progressive increases in training load, macrocycles lasting about 14-15 weeks, and substantial volume of training at intensities ≤4 mmolâ L-1 and >6 mmolâ L-1, were associated with peak performance in elite swimmers.
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OBJECTIVES: The purpose of this study was to quantify the impact of morphological characteristics on freestyle swimming performance by event and gender. DESIGN: Height, mass, body mass index (BMI) and speed data were collected for the top 100 international male and female swimmers from 50 to 1500 m freestyle events for the 2000-2014 seasons. METHODS: Several Bayesian hierarchical regressions were performed on race speed with height, mass and BMI as predictors. Posterior probability distributions were computed using Markov chain Monte Carlo algorithms. RESULTS: Regression results exhibited relationships between morphology and performance for both genders and all race distances. Height was always positively correlated with speed with a 95% probability. Conversely, mass plays a different role according to the context. Heavier profiles seem favourable on sprint distances, whereas mass becomes a handicap as distance increases. Male and female swimmers present several differences on the influence of morphology on speed, particularly about the mass. Best morphological profiles are associated with a gain of speed of 0.7%-3.0% for men and 1%-6% for women, depending on race distance. BMI has been investigated as a predictor of race speed but appears as weakly informative in this context. CONCLUSION: Morphological indicators such as height and mass strongly contribute to swimming performance from sprint to distance events, and this contribution is quantified for each race distance. These profiles may help swimming federations to detect athletes and drive them to compete in specific distances according to their morphology.
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This study investigated the inter- and intra-lap variability in stroking parameters during sprint competition to gain insight into the race management of speed (S), stroke length (SL), stroke rate (SR) and stroke index (SI) in relation to gender. The stroking parameters of 32 male and 32 female finalists in the 2015 World Championships and French Championships were analysed during 50-m and 100-m freestyle events. Using a video-derived two-dimensional direct linear transformation system, the biological coefficients of variation (BCV) between cycles were computed for the 50-m and the two laps of the 100-m (L1100, L2100). Speed changes within each lap were modelled by linear, quadratic or cubic models. The 50-m showed higher S and SR but lower SL and SI than L1100. The 50-m exhibited greater BCV S than L1100, which showed higher S, SR, SL and SI than L2100. BCV S and BCV SL were lower in L1100 than L2100 but BCV SR was higher in L1100 than L2100. Male swimmers showed greater BCV S than female swimmers in the 50-m and L1100. For the whole population, the linear regression model was dominant in the 50-m (53.1%), L1100 (53.1%) and L2100 (43.8%). High mean speed often related to high intra-lap speed fluctuations and a linear speed decrease in the 50-m suggesting an 'all-out' pacing, while lower fluctuations occurred during the 100-m suggesting an 'economical' pacing.
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Rendimiento Atlético/fisiología , Natación/fisiología , Adulto , Femenino , Humanos , Modelos Lineales , Masculino , Adulto JovenRESUMEN
PURPOSE: To compare the dynamics of maximal oxygen uptake ([Formula: see text]), blood lactate ([La]b), total energy expenditure (Etot), and contributions of the aerobic (Eaer), alactic anaerobic (Ean,al), and lactic anaerobic (Ean,lac) metabolic energy pathways over 4 consecutive 25-m laps (L0-25, L25-50, etc) of a 100-m maximal freestyle swim. METHODS: Elite swimmers comprising 26 juniors (age = 16 [1] y) and 23 seniors (age = 24 [5] y) performed 100 m at maximal speed and then 3 trials (25, 50, and 75 m) at the same pace as that of the 100 m. [La]b was collected, and [Formula: see text] was measured 20 s postexercise. RESULTS: The estimated energetic contributions for the 100-m trial are presented as mean (SD): Eaer, 51% (8%); Ean,al, 18% (2%); Ean,lac, 31% (9%). [Formula: see text] increased from L0-25 to L25-50 (mean = 3.5 L·min-1; 90% confidence interval [CI], 3.4-3.7 L·min-1 to mean = 4.2 L·min-1; 90% CI, 4.0-4.3 L·min-1) and then stabilized in the 2nd 50 m (mean = 4.1 L·min-1; 90% CI, 3.9-4.3 L·min-1 to mean = 4.2 L·min-1; 90% CI, 4.0-4.4 L·min-1). Etot (juniors, 138 [18] kJ; seniors, 168 [26] kJ), Ean,al (juniors, 27 [3] kJ; seniors, 30 [3] kJ), and Ean,lac (juniors, 38 [12] kJ; seniors, 62 [24] kJ) were 11-58% higher in seniors. Faster swimmers (n = 26) had higher [Formula: see text], 90% CI 4.4-4.8 L·min-1 [Formula: see text] L·min-1, 90% CI 3.6-4.2 L·min-1), and Eaer power was associated with fast performances (P < .001). CONCLUSION: Faster swimmers were characterized by higher [Formula: see text] and less time to reach the highest [Formula: see text] at â¼50 m of the 100-m swim. Anaerobic qualities become more important with age.
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Metabolismo Energético , Consumo de Oxígeno , Natación/fisiología , Adolescente , Adulto , Factores de Edad , Rendimiento Atlético/fisiología , Humanos , Ácido Láctico/sangre , Masculino , Adulto JovenRESUMEN
Periodization of swim training in the final training phases prior to competition and its effect on performance have been poorly described. We modeled the relationships between the final 11 weeks of training and competition performance in 138 elite sprint, middle-distance, and long-distance swimmers over 20 competitive seasons. Total training load (TTL), strength training (ST), and low- to medium-intensity and high-intensity training variables were monitored. Training loads were scaled as a percentage of the maximal volume measured at each intensity level. Four training periods (meso-cycles) were defined: the taper (weeks 1 to 2 before competition), short-term (weeks 3 to 5), medium-term (weeks 6 to 8), and long-term (weeks 9 to 11). Mixed-effects models were used to analyze the association between training loads in each training meso-cycle and end-of-season major competition performance. For sprinters, a 10% increase between â¼20% and 70% of the TTL in medium- and long-term meso-cycles was associated with 0.07 s and 0.20 s faster performance in the 50 m and 100 m events, respectively (p < 0.01). For middle-distance swimmers, a higher TTL in short-, medium-, and long-term training yielded faster competition performance (e.g., a 10% increase in TTL was associated with improvements of 0.1-1.0 s in 200 m events and 0.3-1.6 s in 400 m freestyle, p < 0.01). For sprinters, a 60%-70% maximal ST load 6-8 weeks before competition induced the largest positive effects on performance (p < 0.01). An increase in TTL during the medium- and long-term preparation (6-11 weeks to competition) was associated with improved performance. Periodization plans should be adapted to the specialty of swimmers.
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Atletas/psicología , Conducta Competitiva , Entrenamiento de Intervalos de Alta Intensidad , Modelos Biológicos , Modelos Estadísticos , Músculo Esquelético/fisiología , Periodicidad , Acondicionamiento Físico Humano/métodos , Entrenamiento de Fuerza , Natación , Adolescente , Adulto , Factores de Edad , Femenino , Estado de Salud , Humanos , Masculino , Contracción Muscular , Fatiga Muscular , Fuerza Muscular , Resistencia Física , Factores Sexuales , Factores de Tiempo , Adulto JovenRESUMEN
INTRODUCTION: Elite athletes frequently undergo periods of intensified training (IT) within their normal training program. These periods can lead athletes into functional overreaching, characterized by high perceived fatigue, impaired sleep, and performance. Because whole-body cryostimulation (WBC) has been proven to be an effective recovery method in the short term (<76 h), we investigated whether daily WBC sessions during IT could prevent exercise and sleep-related signs of overreaching. METHODS: After a normal training week (BASE), 10 elite synchronized swimmers performed two 2-wk IT periods in a randomized crossover fashion using WBC daily (ITWBC) or not (ITCON), separated by 9 d of light training. Swim time trials (400 m) were performed at BASE and after each IT to quantify blood lactate ([La]B), HR (HR400), salivary alpha amylase ([α-amylase]s400), and cortisol ([cortisol]s400) responses. Swimmers wore a wrist actigraph nightly to monitor sleep patterns. RESULTS: Swim speed (400 m), [La]B400, and [α-amylase]s400 decreased from BASE to ITCON, although no significant changes were found after ITWBC. Decreased swim speed was correlated to decreased HR400 and [cortisol]s400. During ITCON, significant decreases in actual sleep duration (-21 ± 7 min) and sleep efficiency (-1.9% ± 0.8%) were observed, with increased sleep latency (+11 ± 5 min) and fatigue compared with BASE, although these variables did not change during ITWBC. Using a qualitative statistical analysis, we observed that daily WBC use resulted in a 98%, 59%, 66%, and 78% chance of preserving these respective variables compared with ITCON. CONCLUSION: WBC use during IT helped mitigate the signs of functional overreaching observed during ITCON, such as reduced sleep quantity, increased fatigue, and impaired exercise capacity. These results support the daily use of WBC by athletes seeking to avoid functional overreaching during key periods of competition preparation.
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Crioterapia , Fatiga/prevención & control , Trastornos del Sueño-Vigilia/prevención & control , Natación/fisiología , Actigrafía , Estudios Cruzados , Femenino , Frecuencia Cardíaca/fisiología , Humanos , Hidrocortisona/análisis , Ácido Láctico/sangre , Saliva/química , Adulto Joven , alfa-Amilasas/análisisRESUMEN
PURPOSE: The objective of this study is to investigate the relation between sport training and the risk of common illnesses: upper respiratory tract and pulmonary infections (URTPI), muscular affections (MA), and all-type pathologies in highly trained swimmers. METHODS: Twenty-eight French professional swimmers were monitored weekly for 4 yr. Training variables included 1) in-water and dryland intensity levels: low-load, high-load, resistance, maximal strength, and general conditioning training (expressed as the percentage of the maximal load performed by each subject, at each intensity level over the study period); and 2) training periods: moderate, intensive, taper, competition, and postcompetition. Illnesses were diagnosed by a sports physician using a standardized questionnaire. Mixed-effects logistic regression analyses were used to model odds ratios for the association between common illnesses and training variables, adjusted for sport season, semiseason (summer or winter), age, competition level, sex, and history of recent events, whereas controlling for heterogeneity among swimmers. RESULTS: The risk of common illnesses was significantly higher in winter months, for national swimmers (for URTPI), and in cases of history of recent event (notably for MA). The odds of URTPI increased 1.08 (95% CI, 1.01-1.16) and 1.10 (95% CI, 1.01-1.19) times for every 10% increase in resistance and high-load trainings, respectively. The odds of MA increased by 1.49 (95% CI, 1.14-1.96) and 1.63 (95% CI, 1.20-2.21) for each 10% increase in high load and general conditioning training, respectively. The odds of illnesses were 50%-70% significantly higher during intensive training periods. CONCLUSION: Particular attention must be paid to illness prevention strategies during periods of intensive training, particularly in the winter months or in case of the recent medical episode.
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Enfermedades Musculares/diagnóstico , Educación y Entrenamiento Físico , Infecciones del Sistema Respiratorio/diagnóstico , Natación/fisiología , Adolescente , Adulto , Conducta Competitiva/fisiología , Femenino , Humanos , Estudios Longitudinales , Masculino , Enfermedades Musculares/prevención & control , Educación y Entrenamiento Físico/métodos , Ejercicio Pliométrico , Estudios Prospectivos , Entrenamiento de Fuerza , Infecciones del Sistema Respiratorio/prevención & control , Factores de Riesgo , Estaciones del Año , Adulto JovenRESUMEN
PURPOSE: The aim of this study was to model the relationship between training and performance in 13 competitive swimmers, over three seasons, and to identify individual and group responses to training. METHODS: A linear mixed model was used as an alternative to the Banister model. Training effect on performance was studied over three training periods: short-term, the average of training load accomplished during the 2 wk preceding each performance of the studied period; mid-term, the average of training load accomplished during weeks 3, 4, and 5 before each performance; and long-term, weeks 6, 7, and 8. RESULTS: Cluster analysis identified four groups of subjects according to their reactions to training. The first group corresponded to the subjects who responded well to the long-term training period, the second group to the long- and mid-term periods, the third to the short- and mid-term periods, and the fourth to the combined periods. In the model, the intersubject differences and the evolution over the three seasons were statistically significant for the identified groups of swimmers. Influence of short-term training was negative on performance in the four groups, whereas mid- and long-term training had, on the average, a positive effect in three groups out of four. Between seasons 1 and 3, the effect of mid-term training declined, whereas the effect of long-term training increased. The fit between real and modeled performances was significant for all swimmers (0.15 = r2 = 0.65; P = 0.01). CONCLUSION: The mixed model described a significant relationship between training and performance both for individuals and for groups of swimmers. This relationship was different over the 3 yr. Personalized training schedules could be prescribed on the basis of the model results.
Asunto(s)
Educación y Entrenamiento Físico/métodos , Resistencia Física/fisiología , Natación/fisiología , Adulto , Análisis por Conglomerados , Estudios de Cohortes , Femenino , Humanos , Modelos Lineales , Masculino , Aptitud Física/fisiología , Sensibilidad y Especificidad , Análisis y Desempeño de Tareas , Factores de TiempoRESUMEN
The authors tested the effect of cold water ingestion during high-intensity training in the morning vs the evening on both core temperature (TC) and thermal perceptions of internationally ranked long-distance swimmers during a training period in a tropical climate. Nine internationally ranked long-distance swimmers (5 men and 4 women) performed 4 randomized training sessions (2 in the evening and 2 in the morning) with 2 randomized beverages with different temperatures for 3 consecutive days. After a standardized warm-up of 1000 m, the subjects performed a standardized training session that consisted of 10 x 100 m (start every 1'20â³) at a fixed velocity. The swimmers were then followed for the next 3000 m of the training schedule. Heart rate (HR) was continuously monitored during the 10 x 100 m, whereas TC, thermal comfort, and thermal sensation (TS) were measured before and after each 1000-m session. Before and after each 1000 m, the swimmers were asked to drink 190 mL of neutral (26.5 ± 2.5°C) or cold (1.3 ± 0.3°C) water packaged in standardized bottles. Results demonstrated that cold water ingestion induced a significant effect on TC, with a pronounced decrease in the evening, resulting in significantly lower mean TC and lower mean delta TC in evening cold (EC) than in evening neutral (EN), concomitant with significantly lower TS in EC than in EN and a significant effect on exercise HR. Moreover, although TC increased significantly with time in MN, MC, and EN, TC was stabilized during exercise in EC. To conclude, we demonstrate that a cold beverage had a significant effect on TC, TS, and HR during training in high-level swimmers in a tropical climate, especially during evening training.
Asunto(s)
Frío , Agua Potable , Natación/fisiología , Clima Tropical , Adaptación Fisiológica , Adulto , Temperatura Corporal/fisiología , Femenino , Frecuencia Cardíaca/fisiología , Humanos , Masculino , Educación y Entrenamiento Físico/métodos , Factores de Tiempo , Adulto JovenRESUMEN
This study investigated the effect of whole-body cryostimulation (WBC), contrast-water therapy (CWT), active recovery (ACT), and passive condition (PAS) protocols on the parasympathetic reactivation and metabolic parameters of recovery in elite synchronized swimmers who performed 2 simulated competition ballets (B1 and B2) separated by 70 min. After determining maximal oxygen consumption (VÌO(2max400)) and blood lactate concentrations ([La(-)](b400)) during a 400-m swim trial, 11 swimmers performed 1 protocol per week in randomized order. Heart rate variability (HRV) was measured at rest (PreB1), 5 min after B1 (PostB1), before B2 (PreB2), and 5 min after B2 (PostB2). VÌO(2peak) was measured at PostB1 and PostB2, and [La(-)](b) was measured at PostB1, PreB2, and PostB2. PostB1 VÌO(2peak) and VÌO(2max400) were similar, but PostB1 [La(-)](b) was higher than [La(-)](b400) (p = 0.004). Each ballet caused significant decreases in HRV indices. At PreB2, all HRV indices had returned to PreB1 levels in the CWT, PAS, and ACT protocols, whereas the WBC protocol yielded a 2- to 4-fold increase in vagal-related HRV indices, compared with PreB1. WBC and ACT both increased [La(-)](b) recovery, compared with PAS (p = 0.06 and p = 0.04, respectively), and yielded an increased VÌO(2peak) from B1 to B2; however, it decreased after PAS (+5.4%, +3.4%, and -3.6%; p < 0.01). This study describes the physiological response to repeated maximal work bouts that are highly specific to elite synchronized swimming. In the context of short-term recovery, WBC yields a strong parasympathetic reactivation, and shows similar effectiveness to ACT on the metabolic parameters of recovery and subsequent exercise capacity.