Are Young Swimmers Short and Middle Distances Energy Cost Sex-Specific?

Abstract

This study assessed the energy cost in swimming (C) during short and middle distances to analyze the sex-specific responses of C during supramaximal velocity and whether body composition account to the expected differences. Twenty-six swimmers (13 men and 13 women: 16.7 ± 1.9 vs. 15.5 ± 2.8 years old and 70.8 ± 10.6 vs. 55.9 ± 7.0 kg of weight) performed maximal front crawl swimming trials in 50, 100, and 200 m. The oxygen uptake (V˙O2) was analyzed along with the tests (and post-exercise) through a portable gas analyser connected to a respiratory snorkel. Blood samples were collected before and after exercise (at the 1st, 3rd, 5th, and 7th min) to determine blood lactate concentration [La–]. The lean mass of the trunk (LMTrunk), upper limb (LMUL), and lower limb (LMLL) was assessed using dual X-ray energy absorptiometry. Anaerobic energy demand was calculated from the phosphagen and glycolytic components, with the first corresponding to the fast component of the V˙O2 bi-exponential recovery phase and the second from the 2.72 ml × kg–1 equivalent for each 1.0 mmol × L–1 [La–] variation above the baseline value. The aerobic demand was obtained from the integral value of the V˙O2 vs. swimming time curve. The C was estimated by the rate between total energy releasing (in Joules) and swimming velocity. The sex effect on C for each swimming trial was verified by the two-way ANOVA (Bonferroni post hoc test) and the relationships between LMTrunk, LMUL, and LMLL to C were tested by Pearson coefficient. The C was higher for men than women in 50 (1.8 ± 0.3 vs. 1.3 ± 0.3 kJ × m–1), 100 (1.4 ± 0.1 vs. 1.0 ± 0.2 kJ × m–1), and 200 m (1.0 ± 0.2 vs. 0.8 ± 0.1 kJ × m–1) with p < 0.01 for all comparisons. In addition, C differed between distances for each sex (p < 0.01). The regional LMTrunk (26.5 ± 3.6 vs. 20.1 ± 2.6 kg), LMUL (6.8 ± 1.0 vs. 4.3 ± 0.8 kg), and LMLL (20.4 ± 2.6 vs. 13.6 ± 2.5 kg) for men vs. women were significantly correlated to C in 50 (R2adj = 0.73), 100 (R2adj = 0.61), and 200 m (R2adj = 0.60, p < 0.01). Therefore, the increase in C with distance is higher for men than women and is determined by the lean mass in trunk and upper and lower limbs independent of the differences in body composition between sexes.

Sex-Specific Effect on Accumulated Oxygen Deficit During Short and Middle-Distance Swimming Performance

“…Earlier researches on swimming anaerobic requirements have reported the total oxygen debt and the peak blood lactate concentrations ([La − ]) in high-intensity performance at 15-18 LO 2 and 12-18 mmol×L − 1 as the reference range of values (Holmér 1979;Vescovi et al, 2011). Furthermore, the latest studies that assessed energetics during high-intensity swimming bouts, particularly using the accumulated oxygen de cit (AOD) method, but not only, corroborated the evidence that anaerobic metabolism is a fundamental source of energy released during short-and middle-distances swimming performances (Peyrebrune et al, 2012;Zacca et al, 2020;Massini et al, 2021).…”

“…An independent t-test (2-tailed) compared sexes regarding body composition, VȮ 2max , and vVȮ 2max , with the corresponding effect size being calculated using Hedges g: <0. 19 [trivial], 0.20-0.49 [small], 0.50-0.79 [medium], 0.80-1.29 [large], and >1.30 [very large] (Rosenthal, 1996). Two-way ANOVA (with Sidak as posthoc) compared the effect of sex and exercise distances on AOD.…”

Time limit and V̇O2 kinetics at maximal aerobic velocity: Continuous vs. intermittent swimming trials

“…With regard to the use of the new-Aquatrainer ® for the sampling of gas exchange response, it could not be recognized as a limitation for physiological analysis, even when considering that this system delays the actual swimming velocity through the modification of swimming tasks such as turning and gliding (Ribeiro et al, 2016), and supposedly allows a higher contribution of oxidative energetic system than expected during high-intensity short-and middle-trials performances (Campos et al, 2017). Indeed, there are reports stating that a swimmer is able to stroke at a maximum rate when required while wearing new-Aquatrainer ® , and therefore no impairments are expected for the level of exertion during swimming tests (Ribeiro et al, 2016) and energetic contribution (Almeida et al, 2020;Massini et al, 2021).…”

“…This test was composed of six sets of 250 m, plus one set of 200 m at maximal intensity, with 30 s rest for [La − ] collection (Espada et al, 2015;Almeida et al, 2020Almeida et al, , 2021Massini et al, 2021), in order to allow the determination of maximal oxygen uptake (V _ O 2peak ), VT₂, vVT₂, and MAV. The velocity of the first repetition was set at 50% of the swimmers' 200 m trial velocity (performed 48 h before the beginning of the tests), and increments of 5%-10% were imposed in the remaining repetitions until swimmers' voluntary exhaustion.…”

Sex-Specific Accumulated Oxygen Deficit During Short and Middle-Distance Swimming Performance

“…The use of the New Aquatrainer® to measure the VȮ 2Ac might be considered another limitation to reproduce physiological demand ecologically if considering the delays of the actual swimming velocity as an effect of turning and gliding constraints [23]. However, the swimmer is enabled to stroke at a maximum rate when required, and therefore, task impairments with the New Aquatrainer® would not affect the muscle mass engagement, as well as the level of exertion while swimming [7,21].…”