The reason why exercise has this effect is not clear but the researchers said they believe physical activity somehow defends against the natural process called oxidative stress, which damages and kills cells.

• 虽然锻炼能延缓衰老的原因目前还不清楚，但研究人员认为，运动在某种程度上抵抗了氧化应激的自然过程，这一过程会损坏或杀死细胞。