Prolonging the Warm-Up Effect by Using Additional Respiratory Dead Space Volume After the Cessation of Warm-Up...

Background: After a warm-up and before the start of sports competition, athletes often take a break. During this break, the effects of the warm-up (e.g., capillary vasodilation) may diminish. The aim of this study was to compare cardiorespiratory responses during high-intensity physical exercise, either preceded or not preceded by post-warm-up breathing, using an additional respiratory dead space volume mask (ARDSv). Methods: The study included 20 trained cyclists. Each participant completed two 3 min tests at an intensity of 110% of their maximal power, determined during a progressive test. A standardised warm-up preceded each 3 min test. Following the warm-up, there was an 8 min passive rest period. During this break, participants either breathed using ARDSv or breathed normally (non-ARDSv). The volume of the ARDSv mask was 1000 mL. Cardiorespiratory parameters were measured during the tests, including mean: oxygen uptake (VO₂av), respiratory exchange ratio (RERav), respiratory rate (RRav), tidal volume (TVav), stroke volume (SVav), and rating of perceived exertion (RPE). Results: VO₂peak was higher in participants breathing using ARDSv compared to non-ARDSv (4.22 ± 0.40 [CI: 4.03-4.41] vs. 3.98 ± 0.42 [CI: 3.79-4.18]; p = 0.002; t = 3.56; d = 0.585). Additionally, RERav (1.08 ± 0.06 [CI: 1.06-1.11] vs. 1.13 ± 0.06 [CI: 1.11-1.16]; p = 0.008; t = 2.96; d = 0.833) and RPE (18.0 ± 1.7 [CI: 17.3-18.8] vs. 18.9 ± 1.1 [CI: 18.4-19.4]; p = 0.009; Z = 2.61; r = 0.583) were lower in participants breathing using ARDSv compared to non-ARDSv. Conclusions: Breathing using ARDSv between warm-up and high-intensity exercise increases oxygen uptake and reduces perceived exertion, likely through peripheral mechanisms. These effects suggest practical applications in competitive sports and provide directions for further mechanistic research.