Background
Fatigue is a common physiological phenomenon in sports. There are reports describing the beneficial effects of exposure to Mild Hyperbaric Oxygen Therapy (MHOT) on metabolic diseases. However, the effects of MHOT on exercise-induced fatigue have not been fully investigated. Therefore, this study aimed to analyze the effects of different MHOT intervention time protocols (30 min and 60 min) on one week of endurance exercise-induced fatigue in rats.
Methods
A total of 32 male Wistar rats (aged 6 weeks) were randomly assigned into to control group (C), exercise group (E), MHOT for 30min after exercise group (EMHOT30min) and MHOT for 60min after exercise group (EMHOT60min), with 8 rats in each group. In the exercise group, rats underwent treadmill exercise sessions lasting 90 minutes each day, conducted six times a week, once a day for one week. These exercise sessions were tailored based on the measurement range of maximum oxygen uptake. After each exercise session, the E group underwent a routine quiet rest (1 ATA, 20.9% oxygen). Conversely, the EMHOT30min and EMHOT60min groups were exposed to an MHOT environment for 30 minutes and 60 minutes, respectively (1.25ATA, 26%-28% oxygen concentration). Baseline measurements and aerobic exercise capacity tests were conducted before and after the one-week intervention period. At the end of the intervention, a complete blood count and biochemical analyses of enzyme activity were also performed.
Results
The results show that the MHOT intervention groups significantly increased aerobic exercise capacity and promoted the recovery of blood oxygen content. Moreover, the EMHOT60min group was better than the EMHOT30min group (P < .05). Muscle damage and metabolite levels induced by one week of endurance exercise were significantly reduced in the MHOT intervention groups, with no significant difference observed between the two MHOT groups (P > .05). The MHOT intervention also significantly enhanced antioxidant levels, compared with EMHOT30min group, the effect of EMHOT60min group is more obvious (P < .05).
Conclusions
These data suggest that both the 30-minute and 60-minute MHOT interventions effectively facilitated the reduction of fatigue in rats after one week endurance exercise. Moreover, the 60-minute MHOT intervention demonstrated a superior effect on aerobic exercise capacity and antioxidant capacity. This enhanced effect of the 60-minute protocol might be attributed to the cumulative time-response relationship inherent in MHOT intervention time protocol.