Acute exercise increases resistance to oxidative stress in young but not older adults

A single bout of acute exercise increases oxidative stress and stimulates a transient increase in antioxidant enzymes. We asked whether this response would induce protection from a subsequent oxidative challenge, different from that of exercise, and whether the effects were affected by aging. We compared young (20?±?1 years, n?=?8) and older (58?±?6 years, n?=?9) healthy men and women. Resistance to oxidative stress was measured by the F₂-isoprostane response to forearm ischemia/reperfusion (I/R) trial. Each participant underwent the I/R trial twice, in random order; once after performing 45 min of cycling on the preceding day (IRX) and a control trial without any physical activity (IRC). Baseline F₂-isoprostane levels were significantly lower at IRX compared to IRC (P?2-isoprostane response to IRX was significantly lower compared to IRC in young (P?P?