The Centers for Disease Control and Prevention's 2010 Physical Activity Guidelines for Americans recommend that adults do both aerobic and strength training. Specifically, the guidelines recommend the following:A total of at least 150 minutes of moderate intensity aerobic activity (brisk walking) per week, which translates to about 30 minutes a day, five days a week, and muscle-strengthening activities that work all major muscle groups on two or more days a week orA total of at least 75 minutes of vigorous-intensity aerobic activity (jogging or running) every week and muscle-strengthening activities that work all major muscle groups on two or more days a week orAn equivalent mix of moderate- and vigorous-intensity aerobic activity and muscle-strengthening activities that work all major muscle groups on two or more days a week.The guidelines note that adults can achieve additional health benefits, including the promotion of greater weight loss or the prevention of weight regain, by increasing to five hours (300 minutes) a week of moderate-intensity aerobic physical activity, or 150 minutes a week of vigorous-intensity physical activity, or an equivalent combination of both.