Analysis of determinants of swimming economy in front crawl

Abstract

The purpose of this study was to investigate the relationship between swimming economy, energy cost to move the body per unit distance (CS) at a given velocity (v) and the potential determinants, i.e. performance level, body size, swimming technique and v. A total of 101 males were studied. Three performance levels (A, B, C) were determined, ranging from the slower (A) to the faster times (B, C). At level C and at 1.1 m.s-1, CS 1.1, was reduced by 55% and 25% when compared with levels A and B and when calculated per unit of surface area (SA) and unit of hydrostatic lift (HL). For the whole group of swimmers, CS 1.1 = 21.88 SA-2.15 HL + 5.9 (r = 0.56, P less than 0.01). Among the 101 swimmers, three other groups were selected to evaluate specifically the influence of arm length and swimming technique on CS, i.e. arm or leg swimmers and sprinters versus long-distance swimmers, CS was significantly (P less than 0.05) lower for long-arm swimmers, arm and long-distance swimmers than for short-arm, leg and sprint swimmers by 12%, SD 3.3%, 15%, SD 3.8% and 16.5%, SD 3%, respectively. For all groups, CS increased with v on average by 10% every 0.1 m.s-1. It is concluded that technical ability cannot be interpreted directly from CS. Performance levels, body size, swimming technique and v at which the measurements are obtained must be also taken into account.

Fatores intrínsecos do custo energético da locomoção durante a natação

“…Moreover, this method (retro extrapolation) has been valid (r = 0,99) and reproducible (r = 0,92) for the determination of the VO 2max (4) . Recently, continuous measurements of VO 2 have been taken during attached swimming (4) , swimming flume (5) and free swimming (1,6) .…”

“…The amount of metabolic energy used in transporting one's body mass by distance unit has been defined as energy cost of locomotion, or specifically for swimming, swimming cost (Sc, kJ·m -1 ) (2) . The Sc has been usually measured through the ratio between the VO 2 and its corresponding progression velocity for velocities within the zone of aerobic intensities (2,(6)(7)(8) . Besides that, the Sc has also been estimated in supramaximal velocities in which the anaerobic energy contribution is considered in the calculation of the exercise total energy balance (9)(10) .…”

“…Besides that, the Sc has also been estimated in supramaximal velocities in which the anaerobic energy contribution is considered in the calculation of the exercise total energy balance (9)(10) . Results of some studies which investigated the Sc have suggested that height (H) (11)(12) , body mass (M) (11) , body surface area (BSA) (6)(7) , passive torque (9) , floating (6) , and differences in technique (13) may influence the Sc in swimming.…”

“…In the study by Pendergast et al (14) , the differences remained even when the Sc was adjusted by the BSA. However, some studies have shown that these differences between genders disappear when the Sc is adjusted by the M and BSA (6)(7)16) . This difference in the Sc which occurs between men and women may be explained by the different body density and anthropometrical characteristics.…”

Resposta ventilatória durante a prova de 400 metros livres: associações com a prestação

“…Assim, esses factores podem também ter determinado os valores baixos de lactatemia máxima, comparativamente com a literatura. C Cu us st to o e en ne er rg gé ét ti ic co o O custo energético na natação (C E ) por unidade de distância a uma dada velocidade, varia em larga escala entre nadadores 7 . Esta variação faz-se sentir na economia de nado que é definida como o consumo de oxigénio (VO 2 ) necessário para nadar a uma dada velocidade, tal como, o declive da recta de regressão entre o VO 2 e o trabalho da actividade 15 .…”