Time to put some muscle into it
We walk, run, and swim for health reasons. But a well-rounded exercise program needs to include strength training, too.
Exercise is on every to-do list we can think of for staying healthy, and there's pretty wide agreement on how much is necessary.
The physical activity guidelines issued in 2008 by the federal government echoed other guidelines by recommending that American adults get at least two and a half hours of "moderate intensity" aerobic exercise a week. Aerobic exercise is any repeated motion that increases your heart and breathing rates so that more oxygen reaches your muscles. Walking at a fast pace of three to four miles per hour (three is brisk; four can feel downright fast) is often held up as the beau ideal of moderate intensity: inexpensive, no special training or equipment needed, and manageable by many, although many may need to work up to the full weekly amount. The government guidelines have made it even easier by giving us license to get this exercise in 10-minute allotments.