The 2008 Physical Activity Guidelines for Americans  are designed so people can easily fit physical activity into their daily plan and incorporate activities they enjoy.
These guidelines recommend that each week you do one of the following:
Make sure that you do at least 10 minutes of aerobic activity at a time. In fact, people who engage in short bursts of physical activity for 10 minutes at a time have been shown to be just as healthy as people who do a regular 30-minute workout every day. Check out ABE for Fitness  to learn ways to incorporate bursts of physical activity naturally into your daily life.
In addition, include muscle strengthening activities, such as weight training, push-ups, sit-ups, carrying heavy loads, or heavy gardening, at least two days a week. Exercise specialists, such as the American College of Sports Medicine, also recommend incorporating stretching and other exercises to increase flexibility and avoid injury, as well as exercises to improve balance and reduce risk of falls.
Read about specific recommendations for special conditions , such as women who are pregnant, adults with disabilities, and older adults or those with a chronic condition.
In his Blue Zones research on people who live over 100 years, Dan Buettner set out to identify the habits and behaviors that centenarians share. One key characteristic he found was that these people set up their lives so that movement and physical activity became a regular part of their routine. Rather than joining gyms or lifting weights, they get exercise by gardening, walking, climbing stairs, and performing housework. Finding ways that make sense for you to move more often, such as taking your dog for a long morning walk or biking to work, can be an effective way of designing a routine that encourages you to exercise without thinking about it.
While exercise is undoubtedly beneficial, it is not true that the more exercise you do or the harder you work the body, the better the results. Too much or too arduous physical activity can lead to injury. It is essential to maintain a balance between working out the muscles without overdoing it. Know that your body gets stronger during rest and recovery.