Quantitative analysis of the front crawl in men and women

Abstract

Body drag, D, and the overall mechanical efficiency of swimming, e, were measured from the relationship between extra oxygen consumption and extra drag loads in 42 male and 22 female competitive swimmers using the front crawl at speeds ranging from 0.4 to 1.2 m/s. D increased from 3.4 (1.9) kg at 0.5 m/s to 8.2 (7.0) kg at 1.2 m/s, with D of women (in brackets) being significantly less (P less than 0.05) than that of men. Mechanical efficiency increased from 2.9% at 0.5 m/s to 7.4% at 1.2 m/s for men, the values for women being somewhat greater than those for men. The ratio, D/e was shown to be identical to the directly measured energy cost of swimming one unit distance, V02/d, and was independent of the velocity up to 1.2 m/s. It averaged 52 and 37 l/km for men and women respectively (P less than 0.05). When corrected for body surface area the values were 27 and 22 l/km-m2 for men and women, respectively (P less than 0.05). The underwater torque, T, a measure of the tendency of the feet to sink, was 1.44 kg-m for men and 0.70 kg-m for women (P less than 0.05). VO2/d increased linearly with T for both men and women of similar competitive experience. However, the proportionality constant delta VO2/d-delta T was significantly less for competitive than noncompetitive swimmers. The analysis of the relationship VO2/d vs. T provides a valuable approach to the understanding of the energetics of swimming.

Trends in Triathlon Performance: Effects of Sex and Age

“…[65] Buoyancy is also improved in females through a lower "underwater torque", which can be defined loosely as the tendency for the feet to sink. [66] In addition, in contrast to running where the energy cost appears to be similar between females and males, the energy cost of freestyle swimming has been shown to be significantly higher (i.e. lower economy) in males compared to females.…”

“…lower economy) in males compared to females. [66,67] At a velocity of 1 m/s, there are differences in drag force and coefficient of drag between males and females. [68] The energy cost of swimming depends essentially on the propelling efficiency of the arm stroke and hydrodynamic resistance, but it has been suggested that differences in energy costs of swimming between sexes are mainly to be attributed to differences in hydrodynamic resistance.…”

“…[69] Females have smaller body size (resulting in smaller body drag), smaller body density (greater fat percent) and shorter lower limbs, resulting in a more horizontal and streamlined position and therefore a smaller underwater torque. [64,66] …”

Best performances by men and women open-water swimmers during the ‘English Channel Swim’ from 1900 to 2010

“…In contrast, anthropometric characteristics were not related to race performance in men swimmers in a 12-hour ultra-endurance pool-swim (Knechtle, Knechtle, & Kohler, 2008 (www.wrswim.com), with a sex difference of ∼10-12% (Lepers, 2008;Lepers & Maffiuletti, 2011). Swimming economy is higher in women than men (Lavoie & Montpetit, 1986;Pendergast et al, 1977). Indeed, in contrast to running where oxygen cost is similar for both sexes, the energy cost of freestyle swimming is higher (i.e.…”

“…Indeed, in contrast to running where oxygen cost is similar for both sexes, the energy cost of freestyle swimming is higher (i.e. lower economy) in men than women (Pendergast et al, 1977). The higher economy of women has been attributed to a smaller body size resulting in less body drag, a lower body density with a greater fat percent, and shorter lower limbs, resulting in improved horizontal and streamlined positions (Lavoie & Montpetit, 1986;Pendergast et al, 1977).…”