By choosing the right exercise program, you can make your natural athleticism work for you. Avoid heavy-duty exercise programs that trim off inches for a little while but may not work in the long run because they can cause burnout.
For long-term results, find activities that you enjoy, instead of merely choosing those that burn calories. You probably already know some of the activities you do and don't like, so select those you prefer and drop the ones that bore or stress you.
For instance, are you starting to dread your usual five-mile run? If so, give yourself permission to take a leisurely bike ride or swim. Too tired for a 30-minute workout? Exercise for 15 minutes, and see if you feel like continuing. And if you find yourself setting harder and harder goals ("I need to run an eight-minute mile"), reconsider your priorities. Remember that getting regular, moderate exercise is smarter and more effective than forcing yourself to do grueling workouts that can lead to injury or burnout.
You might enjoy the challenge of participating in a run or bike race for charity -- a great way to get exercise while meeting new people and helping your community. You might even want to train for a half-marathon, if running is your favorite activity. Just be sure to make fun and stress reduction your top priorities!