Effects of hyperbaric oxygen on aerobic performance in a normobaric environment

The purpose was to examine the acute effects of a hyperbaric oxygen (HBO2) treatment on a) recovery following prolonged exercise and b) aerobic perfor mance in a trained population. Subjects were six male and six female, train ed runners with mean VO2max values of 64.6 +/- 5.6 and 51.9 +/- 6.6 ml.kg(- 1).min(-1), respectively. Subjects performed four exercise-HBO2 conditions in random order: a) control, b) exercise-no HBO2, c) no exercise-HBO2; and d) exercise-HBO2. Exercise was a 90-min run at 75-80% of VO2max. HBO2 treat ments consisted of breathing 95% O-2 at 2.5 atm abs for 90 min. At the end of each condition, aerobic performance was assessed with a VO2max test and by the oxygen cost of running on a treadmill at three submaximal velocities . Recovery was not enhanced following a single HBO2 treatment at 2.5 atm ab s for 90 min, nor did it alter submaximal or maximal running performance.