Cabric
Hyperbaric oxygen breathing improved exercise performance and oxygen consumption in normobaric conditions for 3 hours following exposure.
Clinical Bottom Line: 1. Hyperbaric oxygen exposure improved performance capacity and oxygen consumption for at least 3 hours post-exposure. Appraised by: Mike Bennett, Dept of Diving and Hyperbaric Medicine, Prince of Wales Hospital Sydney; Monday, 18 January, 1999
Clinical Scenario: An athlete presents suggesting that aerobic performance will be enhanced by exposure to hyperbaric oxygen. Three-part Question: In athletes, does exposure to hyperbaric oxygen compared to normal air breathing, result in enhanced aerobic performance and for how long? Search Terms: Hyperbaric oxygenation, exercise.
The Study: Non-blinded randomised controlled trial with intention-to-treat. Fit female physical education students with no specific contra-indications to hyperbaric oxygen. Control group (N = 18 ;18 analysed): All participants had a standard treadmill test with increasing exertion required in a discontinuous manner, three days before hyperbaric exposure. Experimental group (N = 18 ;18 analysed): All participants were randomised into three arms and then had hyperbaric oxygen at 2.8 ATA for 60 minutes. Each group was tested at a different time post-HBO: 30 mins, 3 hours and 6 hours after completion of HBO protocol.
The Evidence:
| Non-event outcomes | Before | After | P-value |
| Maximum performance (30 mins group) | 10.1 | 11.4 | <0.05 |
| Maximum performance (3 hour group) | 10.5 | 12.4 | <0.05 |
| Maximum performance (6 hour group) | 11.6 | 12.7 | >0.05 |
Comments: 1. Placebo effect of hyperbaric oxygen not tested - no blinding of subjects. 2. The ventilation dependent oxygen uptake ratio, respiratory exchange ratio and lactate concentrations before and after HBO exposure did not change significantly in any group. 3. No a priori justification is made for the choice of times to test performance.
Expiry date: March 2021 References: 1. Cabric M, Medved R, Denoble P, Zivkovic M, Kovacevic H. Effect of hyperbaric oxygenation on maximal aerobic performance in a normobaric environment. Journal of Sports Medicine and Physical Fitness 1991; 31:362-366.
