Effects of hyperoxic gas generator on fatigue recovery after exercise

Introduction

It has been known that breathing hyperoxic gas during exercise has an effect on the prolongation ofexercise and the reduction of blood lactate level. Recently, a few kinds of small machines, allegedly to supply hyperoxic gas and so-called "hyperoxic gas generator", are in the market for general people, suggesting that the machine effects the fast recovery from fatigue by breathing the air from the machine after exercise. However, theevidence is not necessarily persuasive. The purpose of the study was to investigate whether the hyperoxic gas generator is effective on the recovery from fatigue after exercise.

Methods

Ten healthy male subjects performed two trials; each consisting of ten minutes of exercise at the workload of 65%VO2max on a bicycle ergometer and twenty minutes of recovery. The hyperoxic gas generator was applied to the one trial during recovery in order to find its effect. The gas generator used in this study was mounted a special film to raise oxygen concentration of the air and sent the concentrated air (30%O2) through a pipe. The end of the pipe was set in front of the nostril with in a couple of cm in accordance with the user’s manual. Blood samples were collected at 0, 3, 6, 10, 15 and 20 min after each exercise, and blood lactate concentration was measured. Heart rate and expired gas were measured during the experiments. The subjects were questioned their feeling after each trial using a questionnaire.

Results

In the change of the blood lactate concentration, the heart rate, and other respiratory responses during recovery, no significant difference was found between the cases of using the hyperoxic gas and not using it. The questionnaire investigation showed no significant difference.

Discussion/Conclusions

The experimental conditions where the proceeding researchers have found the effect were set in this study, but no effect was seen. The main reason for this result is that oxygen concentration actually inhaled was lower than 30% (the reported lowest concentration for the effect). Actually, oxygen concentration measured in the nostril was greatly lower than 30%. Although it is not necessarily clear about the fundamental issues of hyperoxic gas breathing after exercise, the result indicates that the hyperoxic gas generator which is allegedly to supply hyperoxic gas is not effective on the recovery after exercise fatigue in this experimental condition.

References

[1]. Robbins,M.K.,Gleeson,K., and Zwillich,C.W.(1992) Med.Sci.Sports Exerc.,24,720-725
[2]. Maeda,T. and Yasukouchi,A.(1998)Appl. Human Sci.,17,33-40