Abstract:
The purpose of this work was to study the effects of 30 minutes exposure to 2.5 ATA with 100% O2 inhalation (hyperbaric oxygenation) on lactate concentration after muscular fatigue from incremental exercise on a cycle ergometer. The volunteers in this study are 60 naval male cadets, age 20-23 years with physical fitness above average healthy Thai male or possibly equivalent to male athletes. All volunteers participated in first VO2max exercise test to obtain baseline data and to ensure that all volunteers were rather homogeneous in VO2max. Then the volunteers were randomly assigned into 3 groups of 20 volunteers each. These three groups were : Rest recovery group (RR), rest by sitting at ambient ; Oxygen recovery group (OR), sit at ambient with 100% O2 inhalation through O2 mask ; Hyperbaric oxygenation (HBO2) recovery group (HR), sit in pressurized chamber at 2.5 ATA with 100% O2 inhalation through O2 mask. At experiment, group of volunteers had taken the incremental exercise test (Ordinary lamp protocol) on cycle ergometer to exhaustion, then separated into the assigned recovery group. Blood samples were taken from each volunteer before experiment, at exhaustion and at 5 minute interval after exhaustion for the total of 30 minutes and assayed for lactate concentration. The results showed that there was no significant difference in the decrease of blood lactate concentration throughout the recovery period. But there were significant differences (p<0.05) in blood lactate concentration at 20 and 25 minute interval after exhaustion between RR (10.3+-2.4 ; 9.0+-2.0 mmol/L, respectively) and HR (8.3+-2.7 ; 7.2+-2.4 mmol/L, respectively). Significant difference (p<0.05) in blood lactate concentration at 15 minute interval during recovery was observed between OR group (11.6+-2.8 mmol/L) and HR group (9.4+-3.0 mmol/L). From the data, it may be initially concluded that HBO2 enhances the rate of lactate removal from peripheral blood vessels and therefore shortened the recovery time.
