You love adventure sports, but he prefers computer games. You're a pizza girl, while he spends happy hours preparing French cuisine. It's not unusual for couples to discover they have few passions in common once the romance dies down a bit, but that doesn't necessarily spell disaster. Happy couples work at their marriage by cultivating common interests they can enjoy together.

Dating Couples Make an Effort

Life looks different when a couple first gets together. One partner often participates willingly in the other's favorite activities while they are dating -- the stay-at-home type tries out wilderness camping, and the adventurer delights in quiet evenings at home with a new love. But after a few years of marriage, spouses often slip back into their preferred routines and stop making an effort. Sooner or later, each of them feels that the other just isn't much fun anymore.

Married Couples Must Make an Effort, Too

If you want a strong marriage, you have to keep making an effort, explains Mark Goulston, clinical psychiatrist and UCLA professor. Common interests are critical to a marriage, Dr. Goulston advises. If you and your spouse don't naturally share leisure preferences, you'll need to find new activities to enjoy together. While raising kids provides common ground for awhile, it's best to keep the one-on-one connection going by finding ways for just the two of you to enjoy time together.

Challenging Activities Bring the Most Satisfaction

Research indicates that one way to keep passion alive in your marriage is to seek out novel experiences to try together. Just spending time together is essential, according to Susan Krauss Whitbourne, Ph.D., professor of Psychological and Brain Sciences at the University of Massachusetts Amherst. To some extent, couples increase intimacy by simply cleaning out the basement or working in the garden together. But, if you engage in activities that challenge you physically or mentally, you'll increase your relationship satisfaction even more.

Passion for Life Fires Up Your Marriage

Although common activities bring a couple together, Whitbourne counsels spouses not to neglect their individual passions. When you put emotional energy into your own hobbies and interests, the zest spills over into your married life. It doesn't matter what you get excited about -- the very fact of engagement increases the depth of the feelings you invest in your spouse. Having a strong passion for life is one key to a long and happy marriage.