Aging seems to be inevitable and gradual loss of physical activity is associated with frailty and many age-related disorders. Exercise is the way of keeping a healthy life and delaying aging process. Deterioration in pulmonary vital capacity is inevitable, and mitochondrial biogenesis also diminishes with aging. Regular aerobic exercise alleviates the diminishing vital capacity while increasing mitochondrial biogenesis in aging. Peroxisome proliferator-activated receptor c coactivator 1 alpha (PGC-1a), which is the master regulator of mitochondrial biogenesis, is activated by reactive oxygen species (ROS). Exercise-induced lactate leads to formation of ROS and synthesis of nitric oxide (NO) at physiological level. PGC1a regulation by NO seems to be controversial. Over the physiological limit of ROS and NO has toxic effects in cellular environment with reduced antioxidant activities in aging. Overall, exercise seems to be beneficial option to alleviate reduction rate of vital capacity and to enhance mitochondrial biogenesis via lactate-induced ROS formation.