(A) Testosterone increased mitochondrial DNA (mtDNA) copy number when normalized to nuclear genome DNA (nDNA). (B) Testosterone increased mtDNA-encoded mitochondrial transcripts for markers of complex I (NADH dehydrogenase subunits: ND1, ND4), complex III (cytochrome b: Cyto b), complex IV (cytochrome c oxidase subunits: Cox2a and Cox3a), and complex V (ATP synthase subunit 6, APT6) of the electron transport chain. (C) Testosterone increased the expression of selected nuclear genome-encoded mitochondrial transcripts for δ-aminolevulinate synthase 1 (ALAS1), adenine nucleotide translocator (ANT), Carnitine palmitoyltransferase 1(CPT1β, CPT1α). pyruvate dehydrogenase kinase 4 (PDK4), medium-chain acylCoA dehydrogenase (MCAD), uncoupling protein 3 (UCP3), and cytochrom c (Cyto c). All qPCR results were normalized to house-keeping gene Hypoxanthine phosphoribosyltransferase (HPRT) and expressed in an arbitrary unit (a.u). All results were obtained from triceps and presented as mean ± SEM and compared by t test. N = 5 for the control (C) and N = 8 for the testosterone (T) group.