The USDA Dietary Guidelines for Americans now include an estimated amount of daily exercise needed in order to reduce the risk of chronic disease and to manage body weight.
To prevent chronic disease, engage in moderate exercise for at least 30 minutes every day. Moderate exercise means maintaining an elevated heart rate, but not so intense that you cannot hold a steady conversation. If your goal is to prevent weight gain in adulthood, it is recommended to do 60 minutes of moderate to vigorous exercise most days of the week. When engaging in vigorous activity, you should definitely break a sweat and find it more difficult to maintain a conversation. Lastly, in order to achieve sustainable weight loss in adulthood, the USDA recommend 60 to 90 minutes of moderate exercise on most days of the week. You would choose one of these three options according to what your goals are.
Walking is an excellent form of moderate exercise, as long as you walk quick enough to get that heart rate up! You can walk the dog/push a stroller, do yoga or pilates (both can be tailored to more vigorous workouts as well), chores like washing your car inside and out, cleaning the house etc. Basically anything that gets your heart rate up.
Slightly more intense, this includes running, biking, swimming, weight training/lifting, taking an exercise class, bikram yoga, and playing football, volleyball, basketball, soccer, etc.
You can switch it up throughout the week as well. Maybe on the weekends and two/three days a week you engage in moderate exercise for 30 to 60 minutes (like go for a walk), and then for two days out of the week you do a vigorous activity for 30-60 minutes (like go to the gym).
If you follow me on Twitter, you might already know that my favorite form of exercise is walking. I'm lucky enough to have a lake a couple of blocks from my house and the ocean just a few miles away. Last night was a beach night and I took my landlady's dog along.
Takeaway: Exercise doesn't need to be something you constantly think about and can be an activity you enjoy. For me, I enjoy long walks, while my brother enjoys a pickup game of basketball with his friends. Just keep in mind that exercise is something that is added to your daily routine. For an example, if you already clean the house every day and are still gaining weight you will need to add an activity like a brisk walk or something more intense if you're looking to lose weight. If you have specific questions about weight loss and exercises, your doctor or a Registered Dietician (nutritionist) will be full of helpful information tailored to your physique and current health.