Effects of different oxygen concentrations during intermittent hyperoxic training on endurance capacity in well-trained male mice.
Training at 75% oxygen concentration significantly enhances endurance capacity in well-trained mice, but the implications for human training remain unclear.
Where it sits
this study against the rest of the l-carnitine (levocarnitine) corpusSummary and findings
This study measured the effects of different oxygen concentrations during intermittent hyperoxic training on endurance capacity in well-trained male mice. The mice underwent a 4-week treadmill program after a 7-week voluntary running program. Results indicated that training at 75% oxygen significantly improved endurance capacity compared to normoxic-trained controls.
Abstract
While training under intermittent hyperoxia (INT) enhances endurance capacity, the effects of specific oxygen concentrations remain unclear. This study compared 50% O<sub>2</sub> (INT50) and 75% O<sub>2</sub> (INT75) in well-trained male mice, which had increased maximal work values by 7.7-fold through a 7-week voluntary running program, during a 4-week treadmill program. Results showed that INT75, but not INT50, significantly improved endurance capacity compared to the normoxic-trained (ET) group (Bayes factor, BF ≥3). The enhanced exercise capacity in the INT75 group was linked to higher levels of metabolic enzymes (citrate synthase, 3-hydroxyacyl-CoA-dehydrogenase, carnitine palmitoyl transferase-2, and phosphofructokinase) in the diaphragm and increased pyruvate dehydrogenase complex activity in the red gastrocnemius (Gr) and plantaris (PL) muscles (BF ≥3). Glutathione peroxidase-1 protein levels in the PL muscle were significantly lower in INT75 (vs ET, 0.76-fold, BF ≥3). Additionally, INT75 mice exhibited increased PGC1α levels in the left ventricle, despite decreased cytochrome-c oxidase activity. In contrast, the INT50 group showed a shift toward fast-twitch muscle fibers in the Gr. In conclusion, the ergogenic effects of intermittent hyperoxia depend on oxygen concentration. INT at 75% O<sub>2</sub> significantly enhances endurance capacity in well-trained mice by optimizing metabolic enzyme activity across skeletal and respiratory muscles.
Background
The paper addresses the impact of oxygen concentration on endurance training, a topic of interest given the potential for optimizing athletic performance. Previous research has suggested that oxygen levels can influence training adaptations, but the specific effects of intermittent hyperoxic training remain unclear. This study aims to fill that gap by investigating how different oxygen concentrations affect endurance in trained mice.
Methods
The study utilized a controlled experimental design involving well-trained male mice, but the exact sample size (n) and specific oxygen concentrations used were not reported. The duration of the training regimen and the primary and secondary outcome measures were also not detailed in the abstract.
Results
Not reported in abstract.
Interpretation
Without specific numeric findings or effect sizes, it is difficult to compare this study's results to existing literature or assess the clinical significance of the findings. The lack of reported data limits the ability to draw meaningful conclusions regarding the effectiveness of intermittent hyperoxic training in enhancing endurance capacity.
Key findings
- Not reported in abstract.
Limitations
- Not reported in abstract.
- Rodent model may not translate to humans.
- Specific numeric outcomes not detailed.