CPT1B and Insulin resistance: It has been reported that overexpression of Ppar‐δ in the muscle induces expression of the mitochondrial gatekeeper proteins such as Cpt‐1β and Pdk4, which regulate FA metabolism in the muscle and promote running endurance.9, 10, 51, 52, 53 Consistent with these reports, our study showed that AX treatment upregulated the expressions of Ppar‐δ and Pdk4 in the muscle, which induced mitochondrial gatekeeper proteins to stimulate mitochondrial biogenesis, and also increased the running time and endurance, thereby further ameliorating insulin resistance in the HFD mice.