Longer, less frequent sessions of aerobic exercise have no clear advantage over shorter, more frequent sessions of activity. Any type of aerobic activity contributes to cardiovascular fitness. In fact, even divided "doses" of activity — such as a few five-minute walks spread throughout the day — offer aerobic benefits, and accumulated activity throughout the day adds up to provide health benefits. Any activity is better than none at all. What's most important is making regular physical activity part of your lifestyle.

For most healthy adults, the Department of Health and Human Services recommends:

• At least 150 minutes of moderate aerobic activity or 75 minutes of vigorous aerobic activity a week, or a combination of moderate and vigorous activity. The guidelines suggest that you spread this exercise throughout the week. Moderate aerobic activity may include activities such as brisk walking or swimming, while vigorous aerobic activity may include activities such as running.
• Strength training exercises for all major muscle groups at least two times a week.

As a general goal, aim for at least 30 minutes of moderate physical activity every day. If you want to lose weight, maintain weight loss, gain more health and fitness benefits, or meet specific fitness goals, work to increase your activity even more. For example, you can aim for 300 minutes of moderate physical activity a week, or about 60 minutes or more of moderate physical activity five days during the week.