ABSTRACT
This study aimed to analyse the stability of elite male long-distance swimmers (1500 m), and to identify the main predictors related to the pace. The performance of 16 elite male swimmers (22.59 ± 2.10 years-old) participating in the 1500 m event at the 2016 (London) and 2018 (Glasgow) LEN European Aquatic Championships were analysed. The lap performance, clean swim performance, turn performance, and a set of stroke mechanics variables were assessed. The lap performance presented a significant and moderate variation with all laps included (p < 0.001) and deleting the first and last lap (p = 0.002). Swimmers were significantly faster in the first half in comparison of the second. The total turn also presented a significant and moderate variation. The hierarchical linear modelling retained the time (estimate = 0.0019, p = 0.007), stroke frequency (estimate = -27.49, p < 0.001) and stroke length (estimate = -6.55, p < 0.001) as the main predictors of the clean swim performance. By contrast to the analysis based on the lap performance, clean swim performance presented a non-significant variation. Coaches should be aware that stroke length maintenance could negatively affect the clean swim performance, whereas a small increase of stroke frequency may present a meaningful enhancement of the total race time.
Subject(s)
Athletic Performance , Humans , Male , Young Adult , Adult , Competitive Behavior , Biomechanical Phenomena , SwimmingABSTRACT
Biomechanical and coordination measurements are useful tools to assess swimming performance. Regarding Paralympic swimming, function and technique make these measurements complex. The aim of this study was to perform a systematic review of studies on biomechanics, coordination and performance in disabled swimmers following swimming protocols and in competitions. Data sources: PubMed, EMBASE, ISI Web of Knowledge, SPORTDiscus and Academic Search Premier. We selected complete studies, published until June 2018. Eighteen studies satisfied the inclusion criteria and were selected for qualitative analysis; nine of these were included in the meta-analysis. Swimming speed and stroke length increase with less impact of physical, visual and intellectual impairment on performing specific swimming tasks. Stroke rate is more stable all through the sport classes than both swimming speed and stroke length. Most physically disabled swimmers adopt the catch-up coordination model. Stroke rate is responsible for most of the intracycle velocity variation in swimmers with amputations or malformations of the upper limbs. No study was found on propulsive efficiency. Swimmers with disabilities should work more on stroke rate, with small decreases in stroke length to achieve higher swimming speeds, lower swim coordination index (more negative) and lower speed variations.
Subject(s)
Disabled Persons , Swimming , Arm , Biomechanical Phenomena , HumansABSTRACT
A prova de 200 m nado livre apresenta condições energéticas que oferecem desafios para nadadores, treinadores e cientistas do esporte. Objetivos deste estudo foram identificar (1) a energia total associada a uma prova de 200 m nado livre simulada; (2) a contribuição do metabolismo aeróbio e anaeróbio à energia total; e (3) as correlações entre desempenho, contribuição aeróbia, contribuição anaeróbia e energia total. Participaram 12 nadadores do sexo masculino (idade: 18,3 ± 2,9 anos), cujo melhor tempo na prova de 200 m nado livre era 125,2 ± 2,7 s. Além de variáveis antropométricas, foram obtidos, de 200 m nado crawl, executados em piscina de 25 m, sob máxima intensidade, desempenho em s, transformados em valores pontuais (DESP), considerando o recorde mundial da prova como 1000 pontos. Antes da realização dos 200 m foram identificados o consumo de oxigênio (VO2r) e a concentração de lactato, ambos de repouso ([LAr]). Após os 200 m foram identificados o consumo de oxigênio pós esforço (VO2e), pelo método de retroextrapolação e o pico de concentração de lactato P[LA]. Para identificar os valores de VO2 foi utilizado um analisador de gases portátil e para os valores de [LA] um lactímetro portátil. Dos valores de VO2 e [LA] foram calculados os valores líquidos dos mesmos (VO2l e [LAL] e a energia total (Etot) relativa aos 200 m. O desempenho dos nadadores avaliados foi de 130,2 ± 2,8 s (711,8 ± 29,1 pontos). Valores de VO2l, [LA]L e Etot foram de, respectivamente, 55,5 ± 5,5 ·kg-1·min-1, 11,15 ± 1,17 mmol·l-1 e 67,2 ± 5,5 ml·kg-1·min-1. A contribuição aeróbia foi de aproximadamente 80%. Correlações significativas e negativas foram encontradas entre DESP e VO2l e entre DESP e Etot. Nadadores mais econômicos apresentam melhor desempenho na prova de 200 m nado livre.
Two-hundred meters freestyle event shows unique metabolic energetic conditions offering a challenge for swimmers, coaches and researchers. The aims of this study were to identify (1) total energy associated to 200 m freestyle simulated event; (2) aerobic and anaerobic contribution to the total energy; e (3) correlations between performance and aerobic and anaerobic contribution and total energy. Twelve male swimmers (age: 18.3 ± 2.9 years; best time in the event: 125.2 ± 2.7 s) participated in this study. In addition to anthropometrics variables were obtained, from the 200 m freestyle performed in a 25 m pool at maximal intensity, performance in seconds, transformed in points values (DESP) considering the world record as 1000 points. Prior to the 200 m test resting oxygen consumption and lactate concentrations were determined. After the 200 m test post oxygen consumption, by the backward extrapolation method, and lactate concentration peak [LA] were evaluated. To identify the oxygen consumption values (VO2) and the lactate concentration ([LA]) a portable respiratory gas analyzer and a lactate meter, respectively, were used. From the VO2 and [LA] were calculated the net values (VO2l and [LAL]) and the total expended energy (Etot) during the 200 m. The swimmers performance was 130.2 ± 2.8 s (711.8 ± 29.1 points). Whereas VO2l, [LAL] and Etot were, respectively, 55.5 ± 5.3 ml·kg-1·min-1, 11.15 ± 1.17 mmol·l-1 and 67.2 ± 5.5 ml·kg-1·min-1. Aerobic contribution was around 80%. Significative and negative correlations were found between DESP and VO2l and DESP and Etot. More economic swimmers show better performance in 200 m freestyle event.
