How Much Exercise Do You Need to Improve Your Health?
First the bad news, to get that out of the way: Nearly 80 percent of adults in the U.S. are not getting enough exercise for optimal health, according to the second edition of the Physical Activity Guidelines for Americans, developed by the U.S. Department of Health and Human Services. Children and adolescents are not faring any better. It's estimated that this dearth of physical activity accounts for about $117 billion a year in health care costs and 10 percent of all premature deaths.
Now for the good news: Even a little bit of daily physical activity, of any intensity level, can pay off both in the short and long term. That is, you can greatly benefit simply by sitting less and moving more.
Released in November 2018, the new guidelines are an update from 10 years ago, based on a comprehensive review of research on exercise by a federal advisory committee. They include only recommendations for which the evidence was deemed strong or moderate, and they have since been adopted by the American Heart Association. While they are largely similar to the guidelines from the 2008 edition, they have some notable changes (see #7 and #8 in particular) and also reflect a greater understanding of all that exercise can do.
Here are 10 takeaways about the recommendations for adults to encourage you to get up and get moving.
1. Exercise has well-established health benefits. It's now known that some benefits occur over a short time—even after a single bout of activity—including reduced blood pressure and anxiety and improvements in blood sugar, blood cholesterol, sleep, and certain cognitive functions. Other benefits accrue over the long term, including a lowered risk of cardiovascular disease, type 2 diabetes, dementia, depression, certain cancers (bladder, breast, and colon, for example), and all-cause mortality. Exercise also improves bone health, helps with weight control (though it is not effective as a sole strategy), increases overall quality of life, and improves functioning in people with various chronic illnesses or disabilities, such as Parkinson's disease and strokes. By one estimate, following the guidelines can lower the risk of premature death by 33 percent, compared to being sedentary.
2. For substantial health benefits, adults should do at least 150 minutes a week of moderate-intensity aerobic activity (such as brisk walking, dancing, or housework) or 75 minutes a week of vigorous-intensity activity (such as running, singles tennis, or high-intensity fitness classes). Any exercise is good, but more is better. You can mix it up by combining moderate and vigorous activities during the week (for example, walk briskly for 35 minutes twice a week and jog at higher intensity for 20 minutes twice a week). Activities like bicycling and swimming can be either moderate or vigorous in intensity, depending on the effort you put in.
3. If you're an older adult (over 65), relative intensity is a better guide than absolute intensity in determining what is moderate or vigorous activity. That is, you should consider how effortful a particular activity is for you—with moderate-intensity exercise defined as a 5 or 6 on a scale of 0 (sitting) to 10 (the most effort required), and vigorous beginning at 7 or 8. Depending on your fitness level, even tai chi or yoga (typically considered "light" exercise on an absolute scale) may be perceived as—and thus count as—moderate or vigorous activity.
4. Do the "talk test" to determine the intensity of your workout: For moderate-intensity exercise, you should be able to talk, but not sing. During vigorous exercise, you should be able to say only a few words before needing to take a breath.
5. Also emphasized by the guidelines, for further health benefits, is muscle-strengthening exercise, which should be done at moderate or greater intensity at least twice a week. It should involve all major muscle groups—arms, shoulders, chest, back, abdomen, hips, and legs.
6. Older adults should additionally do balance exercises (such as standing on one foot, walking backwards, or using a wobble board). Along with strength training, this reduces the risk of falls and associated injuries.
7. If all this sounds like a lot, take heart that the new guidelines emphasize that going from being sedentary to any amount of moderate or vigorous activity can have significant benefit. Even light activity is better than no activity, and you can work up to higher intensity and greater duration of activity.
8. Moreover, in a key change from the previous guidelines, the updated ones encourage activity throughout the day in bouts that can be less than 10 minutes (previously, there wasn't enough evidence to recommend such brief activity). Don't have the time (or inclination) to do a 30-minute workout at the gym or a run in the park? How about taking the stairs instead of the elevator, for instance, or doing walking meetings at work?
9. If you need more motivation, consider working with a fitness instructor or coach, either individually or in a group setting, or with a family member or friend. Devices and apps, such as ones that keep track of your steps, can provide feedback about your progress.
10. To avoid injuries, choose activities that are appropriate for you, do them in a safe environment, and wear the proper clothing and, if needed, protective gear; increase activity gradually over time; and talk to your health care provider or a physical activity specialist before starting an exercise program if you have any chronic conditions or symptoms.
BOTTOM LINE: Though physical activity is not a cure-all, nearly all people can benefit from increased amounts, no matter their age, weight, starting fitness level, or health status. As an editorial in the Journal of the American Medical Association about the new guidelines noted, "Multiple studies demonstrate that the steepest reduction in disease risk, such as for coronary heart disease, occurs at the lowest levels of physical activity" (that is, from going from no activity to even just a little) and that "reductions in the risk of disease and disability occur by simply getting moving." Don't overlook the fun factor of physical activity, either—if you find something you enjoy, it won't even feel like exercise.
In addition to advice for adults, the new guidelines include specific recommendations for children (ages 3 to 17), pregnant women, and people with chronic health conditions—all of which can be found at tinyurl.com/exercise-HHS.