High dose vitamin C actually shortens life. Too much antioxydent will prevent natural response to stress such as exercise. So the longevity genes such as sirt1 will be depressed.
http://mobile.nutrai...ter-Animal-data
Can't agree. Have been using Linus Pauling's therapy (high dose vitamin C, beside comprehensive supplementation) and thereby gradually reversed a 60% disability from a severe PAD (due to a 80% stenosis at abdominal aorta) within 6 years. Also not my experience that high-dose antioxidants prevents adaptation in exercise. Just come back from vacations swimming everyday in the ocean - and gradually increased the distance swam, in fact further than ever before in my live.
But beside these anecdotal experiences totally counter to your speculations, please start to understand that animal experiments can't be taken as facts applying exactly to humans for so many different reasons, for example from your link:
... the dose of vitamin E used in the study equates to around 10 grams of alpha-tocopherol for an adult human "which is, in anyone's book, a 'horse dose'."
Holy cow: equivalent to a human dose of 10 grams of vitamin E!!! - But the little vitamin C thrown in gets your blame? 
"It's no surprise it caused a shortening of lifespan as it almost certainly would have acted as a pro-oxidant, this having been widely demonstrated in other species. While the dose of vitamin C was lower, equating to around 4 grams for an adult human, humans are among relatively few mammals that have lost the ability to synthesise our own vitamin C. So once again, the dose offered in the diet, along with the vole's self-produced vitamin C, may have behaved as a pro-oxidant."
