iVillage: You say that if you can walk a mile in 20 minutes, you’re fit. If someone just wants to be in the Pretty Healthy Zone, what are your exercise recommendations?
Dr. Love and Dr. Domar: At different time of your life, the requirements for exercise and fitness change. When you have two young toddlers on your hip for example, you don’t need to be doing additional weight training. Once you hit 50, exercise becomes more important. If you don’t use it at that point in your life, you lose it. Whatever your age, we do recommend that you be as active throughout the day as you can. Climbing the stairs, walking the dog, dancing with your kids all "count" as exercise.