The introduction of Highly Active AntiRetroviral Therapy (HAART) for AIDS and HIV has improved survival considerably. However, HIV patients treated with HAART show significant metabolic symptoms, such as lipodystrophy, dyslipidemia, and insulin resistance. A possible contribution to these dysmetabolic symptoms in HIV/HAART is a decrease in mitochondrial function, resulting in a decreased fatty acid oxidation. Life style modulation such as aerobic exercise and L-carnitine supplementation may be beneficial to mitochondrial function. Aerobic exercise improves the biogenesis and function of mitochondria. A combined regime of aerobic and resistance training has been demonstrated to increase lean body mass and reduce overall fat and truncal fat and the levels of triglyceride and LDL cholesterol. L-Carnitine plays an important role in the transfer of long-chain acyl groups into the mitochondrial matrix and potentially improves energy metabolism. Further, L-carnitine supplementation decreases serum triglyceride levels in HIV/HAART patients with hypertriglyceridemia. However, little is known whether these life style modulations act synergistically in HIV/HAART patients.