Perceived Exertion Associated with Breathing Hyperoxic Mixtures during Submaximal Work.

摘要

The effect of an enriched inspired oxygen concentration on perceived exertion (RPE) was investigated while running at two submaximal treadmill loads. Twelve male volunteers (Vo2 max = 49.3 ml/kg. min) worked at loads of 50% and 80% VO2 max, breathing either air or 80% 02-20% N2 in random order using a single blind technique. After a 1 hr equilibration period with the appropriate gas at rest, the subjects were run at the test work load for 10 min and followed during a 20 min recovery. Heart rate (HR), ventilation (VE), respiration rate (RR), tidal volume (VT) and RPE were measured before, during and after work. Blood lactate was measured 1 min after work. Oxygen concentration did not have a statistically significant effect on HR, VE, RR or VT, at either load during exercise or recovery. At both loads, RPE at the last min of exercise - 1st min of recovery was significantly reduced when breathing the hyperoxic mixture. Mean RPE was reduced from 11.2 at 50% VO2 max breathing room air to 9.6 breathing 02, and at 80% VO2 max from 13.8 to 11.7 (P 0.01). Results indicated that during moderate and heavy work RPE is significantly affected by the inspired 02 concentration and that there is a significant relationship between RPE and blood lactate.