American Heart Association Recommendations for Physical Activity in Adults

Being physically active is important to prevent heart disease and stroke, the nation’s number one killers. To improve overall cardiovascular health, we suggest at least 150 minutes per week of moderate exercise or 75 minutes per week of vigorous exercise (or a combination of moderate and vigorous activity). Thirty minutes a day, five times a week is an easy goal to remember. You will also experience benefits even if you divide your time into two or three segments of 10 to 15 minutes per day.

For people who would benefit from lowering their blood pressure or cholesterol, we recommend 40 minutes of aerobic exercise of moderate to vigorous intensity three to four times a week to lower the risk for heart attack and stroke.

Physical activity is anything that makes you move your body and burn calories.

This includes things like climbing stairs or playing sports. Aerobic exercises benefit your heart, and include walking, jogging, swimming or biking. Strength and stretching exercises are best for overall stamina and flexibility.

The simplest, positive change you can make to effectively improve your heart health is to start walking. It's enjoyable, free, easy, social and great exercise. A walking program is flexible and boasts high success rates because people can stick with it. It's easy for walking to become a regular and satisfying part of life.

AHA Recommendation

For Overall Cardiovascular Health:

• At least 30 minutes of moderate-intensity aerobic activity at least 5 days per week for a total of 150 OR

• At least 25 minutes of vigorous aerobic activity at least 3 days per week for a total of 75 minutes; or a combination of moderate- and vigorous-intensity aerobic activity

AND

• Moderate- to high-intensity muscle-strengthening activity at least 2 days per week for additional health benefits.

For Lowering Blood Pressure and Cholesterol

• An average 40 minutes of moderate- to vigorous-intensity aerobic activity 3 or 4 times per week

What if I can’t make it to the time goal?

Something is always better than nothing!

And everyone has to start somewhere. Even if you've been sedentary for years, today is the day you can begin to make healthy changes in your life. If you don't think you'll make it for 30 or 40 minutes, set a reachable goal for today. You can work up toward your overall goal by increasing your time as you get stronger. Don't let all-or-nothing thinking rob you of doing what you can every day.

Source: http://www.heart.org/en/healthy-living/fitness/fitness-basics/aha-recs-for-physical-activity-in-adults