NRF1 and type 2 diabetes mellitus: Compared with the NC group, the mRNA levels of the mitochondrial biosynthesis-related factors peroxisome proliferator-activated receptor γ coactivator-1α (PGC-1α) (0.11-fold, p < 0.05), mitochondrial transcription factor A (TFAM) (0.35-fold, p < 0.05), and nuclear respiratory factor 1 (NRF1) (0.57-fold, p < 0.05) (Figure 8A–C) were significantly lower in T2DM mice, while 8-week HIIT decreased the mRNA levels of PGC-1α (0.26-fold, p < 0.05), TFAM (1.06-fold, p < 0.05), and NRF1 (0.91-fold, p > 0.05) (Figure 8A–C).