You don't realize how out of shape you are until you are forced to climb a long flight of stairs, and the same can be said about marriage.
You never know how out of shape your relationship is until a crisis hits.
Mort and Ari Fertel, who recently moved to Maryland from Florida, faced a more tragic crisis than most.
They lost a son and then twin daughters after only days of life, and they escaped their pain by running away from each other.
"My wife became very depressed, and I immersed myself in work," Mort Fertel says. "But we didn't want to lose each other. We had lost enough. So we began to work on our marriage."
That is the genesis of "Marriage Fitness" (MarriageMax Inc., $13.95), a new book as well as an approach to marriage that evolved from the Fertels' disappointment with traditional marriage counseling techniques: conflict resolution or effective communication.
Neither enjoyed spending an hour a week digging up the past. And the communication techniques just helped them tell each other how miserable each was.
"I spent hours in libraries and bookstores looking for an approach or an expert that would help us reconnect, and there was nothing there," he said.
"We needed a new way of thinking about marriage."
So, he wrote one himself, demystifying "love" and recommending steps to get your marriage back into shape.
"That deep love which any expert would agree is the goal of marriage is perceived as a mystery," Fertel writes, achieved by accident and easily lost.
But he believes there are "laws" governing the health of a marriage just as diet and exercise determine your physical health.
He recommends steps to "reconnect" with your spouse and rediscover the love that has been lost.
Fertel's approach requires that couples put the marriage first, with date nights and weekends away and a level of attentiveness to each other that most of us have not experienced since the early, heady days of dating.
These are not new ideas, and I have no doubt that shifting focus away from work or kids and back to the partner you have chosen for life is a good thing.
But it is more difficult than ever because of the economic and time pressures under which families struggle today.
Fertel believes that the best thing we can do for our children is to provide them with the example, as well as the emotional comfort, of a good marriage.
"If someone is having an affair, they know they are doing something wrong," he said.
"But if the marriage is suffering because they are trying to be good parents, it is a righteous mistake, and the hardest one to see."
Fertel made a fortune from a mail-order business that he started and then sold. The Wharton School of Business graduate is hoping this will be his next empire, but it will be one in which he passionately believes.
Now the father of a 7-year-old boy and 3-year-old triplets (two boys and a girl), he is evidence that it is possible to put your marriage first, no matter what the level of chaos in the house.
"People start out in love and soon they are looking for ways to endure their marriage. I want more, and I am talking about more than compatibility.
"You can be compatible with a roommate," he said. "I am talking about staying in love with your own spouse."