title: The determinants of performance in master swimmers: a cross-sectional study on the age-related changes in propelling efficiency, hydrodynamic position and energy cost of front crawl.
abstract: The decrease in swimming performance (v                 (max)) that occurs with age is a not only consequence of the physiological decrease in maximal metabolic power ([Formula: see text]) but can also be expected to depend on an increase in the energy cost of swimming (C) [Formula: see text] In turn, for a given speed and stroke C = W                 (d) / (η(P)η(o)) where W                 (d) is hydrodynamic resistance, η(P) is propelling efficiency and η(o) is overall efficiency. The aim of this study was to measure C in 47 male masters (31-85 years old) swimming the front crawl at sub-maximal, aerobic, speeds. During the experiments propelling efficiency and projected frontal area (A                 (eff), an index of W                 (d)) were also determined by kinematic analysis. "Elder" masters (60-80 years) swam at a significantly slower pace (0.65 vs. 0.91 m s(-1)), with a lower η(P) (0.23 vs. 0.31) and a larger A                 (eff) (0.39 vs. 0.23 m(2)) than "younger" masters (30-60 years). No significant differences in C (1.45 kJ m(-1), on the average) were observed as a function of age or speed, but C values were significantly higher than those assessed in young elite swimmers at the very same speeds; the difference increasing with age with a rate of 0.75 % per year. With the due considerations (in this study the observed changes in η(P), A                 (eff) and C can be either attributed to changes in speed or age) these data confirm the hypothesis that an increase in C contributes to the decrease in swimming performance that occurs with age.
authors.affiliation: Department of Neurological, Neuropsychological, Morphological and Movement Sciences, Faculty of Exercise and Sport Sciences, University of Verona, via Casorati 43, Verona, Italy. paola.zamparo@univr.it
authors.forename: P
authors.initials: P
authors.lastname: Zamparo
authors.forename: A
authors.initials: A
authors.lastname: Dall'ora
authors.forename: A
authors.initials: A
authors.lastname: Toneatto
authors.forename: M
authors.initials: M
authors.lastname: Cortesi
authors.forename: G
authors.initials: G
authors.lastname: Gatta
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D054874:Athletic Performance / Q000502:physiology*; D003430:Cross-Sectional Studies; D004734:Energy Metabolism; D006801:Humans; D057446:Hydrodynamics; D008297:Male; D008875:Middle Aged; D013550:Swimming