Republican former Massachusetts Gov. Mitt Romney and his wife, Ann Romney, sat down with ABC News' George Stephanopoulos. In a Sunday exclusive, they discussed Ann Romney's health and how it may affect his campaign. Following is an excerpt from their conversation, which will air this Sunday on "This Week."
George Stephanopoulos: Your sister, Jane, says you have lived a charmed life. What's the toughest personal crisis you've ever had to face?
Former Gov. Mitt Romney, R-Mass.: Well, the charm in my life is that I fell in love young. And you can't imagine what a blessing it is, in my opinion, to find your soul mate so young, to raise five kids together, and to see them get married and have children of their own. It's an extraordinary blessing. But without question, the most difficult time in our life was when Ann was diagnosed with multiple sclerosis.
Stephanopoulos: In 1998.
Ann Romney: Yes.
Mitt Romney: And we were in the doctor's office and she was going through a series of neurological tests.
Ann Romney: I was flunking everything.
Mitt Romney: Her right side wasn't working and we were thinking it could be Lou Gehrig's disease. And we said to each other, "As long as it's not fatal, we can live with anything."
Ann Romney: Well, he thought that.
Mitt Romney: You weren't sure about that.
Ann Romney: No, I was really, really troubled by the disease. It was really tough for me.
It was, obviously, hard for Mitt emotionally to have to support me during that, but for me, I am a physical person that loves action and loves to be involved in sports, and I was a tennis player at that point, and I, interestingly enough, had thought, "My gosh, I'm at the end of my 40s, almost 50 years old, I've made it through that period of life where people get diagnosed with MS."
I mean, I was thinking these thoughts, and then to actually have that diagnosis was just such a stunning blow to me.
Stephanopoulos: You're healthy now.
Mitt Romney: She's healthy.
Ann Romney: I am now.
Mitt Romney: She won't brag on herself, but she's really extraordinary. Of course, she used traditional medicine and Eastern medicine, everything she could think of to get herself strong. But she also started riding horses again.
She rode horses before we really met. She used to have a horse that she'd ride. But when she got sick and was going numb on one side, she said, "I want to ride again." She could barely ride around the arena once or twice without being exhausted.
And this last year, among amateurs, she was ranked number one in New England in dressage. It's an equestrian event.
The woman's a phenomenon.
Stephanopoulos: Are you worried that the stress of the campaign may play in there?
Ann Romney: Yes, I am. Yes, that's a worry. That was part of the decision process that was difficult. And my health obviously is very important to both of us, and so I've got to learn-- I've learned already what to do to keep myself healthy and to try to balance my life and try not to over-fatigue myself.
But I clearly don't have enormous reserves of energy, and I really do hit empty pretty quickly, and I've got to learn how to manage that.
Oh, and you know what it's like. You know how draining these are and how exhausting they are. So I will have to not be with Mitt as much as I'd like to be.
That's why we have five boys.
Stephanopoulos: You're always with him in spirit.
Ann Romney: My boys are great. They're going to step up to the plate, and when I can't always be with him, they're going to be. So you'll be seeing my sons on the campaign trail, and a couple of daughter-in-laws have agreed to do it, as well.
So I feel like, in many ways, I am being carried on the shoulders of a lot of people right now, and my kids are going to really be there and really step forward and step in.
Stephanopoulos: You're in all the way?
Mitt Romney: Oh, yes, we're in all the way. We've given this a lot of thought.
We had a family meeting. We don't have a lot of meetings, but all of us got together Christmas time and every son, every daughter-in-law went around and talked about their views.
They were all concerned. They had their own drawbacks -- concerned about the grandchildren, the impact on them of a presidential race, concern for me, for Ann.
Every single one was unanimous in their view that I should run and they know our heart. They know that we love this country. They know that we think it has a bright future.
They know that we've got some real problems in the country, and they believe that the combination of our experience -- having run a lot of enterprises in trouble, having turned them around and getting things back on track -- that experience, plus our heart, would be helpful to get America on the right course again.
So they said, "Do it." And so we're doing it.