Exercise performance is partially limited by the functionality of the respiratory musculature. Training these muscles improves steady-state exercise performance. However, less is known about the efficacy of executing a respiratory muscle warm-up (RWU) immediately prior to high-intensity exercise. Our study purpose was to use a practitioner-friendly airflow restriction device to investigate the effects of a high, medium, or low intensity RWU on short, high-intensity exercise and pulmonary, cardiovascular, and metabolic function. Eleven recreationally active, males (24.9 ± 4.2 y, 178.8 ± 9.0 cm, 78.5 ± 10.4 kg, 13.4% ± 4.2% body fat) cycled at 85% peak power to exhaustion (TTE) following four different RWU conditions (separate days, in random order): (1) high; (2) medium; (3) low airflow inspiration restriction, or no RWU. When analyzed as a group, TTE did not improve following any RWU (4.73 ± 0.33 min). However, 10 of the 11 participants improved ≥25 s in one of the three RWU conditions (average = 47.6 ± 13.2 s), which was significantly better than (p < 0.05) the control trial (CON). Neither blood lactate nor perceived difficulty was altered by condition. In general, respiratory exchange ratios were significantly lower during the early stages of TTE in all RWU conditions. Our findings suggest RWU efficacy is predicated on identifying optimal inspiration intensity, which clearly differs between individuals.
