ABSTRACT
The purposes of this study were to: (i) compare hip speed fluctuations and swimming economy among three different breaststroke techniques: the flat style (FB), the undulated style (UB), and the new undulated style with overwater recovery of the arms (UOB); and (ii) study the relationships between these parameters. Subjects were 13 national top level swimmers, but for swimming economy tests, only 9 swimmers were studied. Swimming economy profiles for each of the three breaststroke techniques were assessed using net total oxygen consumption (VO2) values and maximal net blood lactate concentrations after exertion. Speed fluctuation profiles were assessed through the photographic light trace of a pulse light device attached to the swimmer. After digitizing, pairs of values for time and speed were modelled using constrained polynomial regression procedures. Using the model, a transformed Strukhal number was calculated as an index of overall speed fluctuations. Results showed that for the speeds studied: (i) UOB was the least economical of the three breaststroke techniques studied; (ii) UOB implies higher speed fluctuations within a stroke cycle than FB and UB; and (iii) speed fluctuations and energy expenditure aie correlated variables when intraindividual results are considered.
