FIGURE 4.

Gut microbiota contributed to the beneficial effects of hypoxia on endurance performance. (A) Time until exhaustion was recorded. After exhaustion, CK (B), BUN (C), and lactic acid (D) were measured immediately. The expression of mitochondrial biogenesis (E) and the mtDNA content (F) were measured by RT-PCR. Representative TEM images (G) and quantification (H) of mitochondria in gastrocnemius muscle at original magnification of ×12,000. Data are presented as means ± SD. *p < 0.05, **p < 0.01, ***p < 0.001 (Student’s t-test, ns, no significance).