Backdraft Oxidative Stress

If provided with antioxidants, our cells are equipped with the means to deal with oxidative stress, but ironically, if those cells don't have enough oxygen to do so, oxygen becomes a lot more harmful when all of a sudden a lot of it comes in, which has the effects of a backdraft. This is why, after ischemia e.g. because of a stroke, too sudden a re-perfusion of blood can cause injury. It's also why it's important to warm up before exercise.