Secretary of State Hillary Clinton has again said she is not planning another presidential bid. 

"I've said I really don't believe that that's something I will do again,"  Clinton said in the interview, which airs Wednesday night as part of Barbara Walters "10 Most Fascinating People" special. (In the above clip, Walters asks the other question apparently on every voter's mind -- what does Clinton do with her hair?). "I am so grateful I had the experience of doing it before."

It's not the first time Clinton has beaten back rumors about her future plans. 

"I think I will serve as secretary of state as my last public position, and then probably go back to advocacy, and probably on behalf of women and children," she said from Bahrain two years ago. A year later, she told Wolf Blitzer that she did not want to be president. In a recent Marie Claire interview, she said she looked forward to cheering for the first woman in the White House from the sidelines. 

Yet the repeated denials have not tampered Clinton speculation -- and interest -- at all. A recent Washington Post-ABC News poll found that 57 percent of Americans would back a Clinton candidacy, including 66 percent of women and 75 percent of people under 50. 

And in the same ABC News interview, Clinton argued that her age is not a factor. 

"I am, thankfully, knock on wood, not only healthy, but have incredible stamina and energy," the 65-year-old said. "I just want to see what else is out there. I've been doing, you know, this, this incredibly important and, and satisfying work here in Washington, as I say, for twenty years, I want to get out and spend some time looking at what else I can do to contribute."

The Fix reported recently that while Clinton's close confidantes very much want her to run, she is not yet thinking about the future. After President Obama's second inauguration, she plans to step down, get some rest and decide what she wants to do next.