| During high intensity endurance exercise, the respiratory muscles fatigue as metabolites accumulate. This results in sympathetic nervous system activation, causing vasoconstriction to the working muscles, and therefore lowered exercise intensity or tolerance. Respiratory muscle warm-up (RMWU) is an intervention that has been shown to delay the detrimental effects of respiratory muscle fatigue and therefore increase both exercise intensity and tolerance. The O2 Trainer is a relatively new device that is considerably simpler and cheaper than those that have been utilized in previous literature. The purpose of this study will be to investigate the effects a RMWU (via the O 2 Trainer) on maximal exercise performance. Thirteen healthy, recreationally active, male subjects (23.15 +/- 2.23 yrs, 178.46 +/- 8.29 cm, 78.96 +/- 11.09 kg, 15.62 +/- 6.27 % body fat) performed a high intensity cycle trial (85% of adjusted peak wattage measured during cycling VO 2max) following four different interventions (on separate days) of 2 sets of 30 breaths: High restriction RMWU, medium restriction RMWU, low restriction RMWU, and control (CON). Time to exhaustion (TTE) was recorded and blood lactate was measured at baseline and post-exercise. Forced vital capacity, forced expiratory volume in one second, forced expiratory volume percent, peak expiratory flow (PEF), and forced inspiratory vital capacity were tested at baseline, post-RMWU, and post-exercise. Metabolic gases and heart rate were measured during exercise and recorded using 15-second averages. The volume of exhaled carbon dioxide and respiratory exchange ratio were significantly lower at the beginning of cycling exercise in nearly all RMWU conditions. PEF was significantly greater at baseline than post RMWU in all conditions including CON. No conditions were shown to significantly affect TTE or blood lactate. Therefore healthy males will not experience any beneficial or detrimental effects to high intensity aerobic performance from implementing RMWU using O2 Trainer. |
