Author: Liz McNett Crowl
10 minutes? 30 minutes? 60 or 90 minutes? How much physical activity is enough? What does it mean to the average American when an organization or expert issues a recommendation for physical activity?
Physical inactivity is a major public health problem. There is compelling scientific evidence that suggests that lack of regular physical activity is a contributing factor in numerous chronic diseases and conditions. Recognition of the hazards of a sedentary way of life has led several groups to make recommendations for physical activity. Because there have been so many different agencies and organizations distributing guidelines for various types of physical activity programs the general public may be confused about which set of guidelines to follow. To help make sense of this information we'll look at a few of the most prominent organizations making recommendations and then discuss how to apply the information some common special situations
Surgeon General 1996
Recommendation: All adults should achieve at least 30 minutes of moderate physical activity, equivalent to brisk walking on most, if not all days of the week.
Special Notes: This report and recommendation is significant because it was the first physical activity recommendation specific for health and it scientifically linked physical activity's role in health and disease prevention.
American College of Sports Medicine and the Center for Disease Control and Prevention
Recommendation: All adults should accumulate at least 30 minutes of moderate physical activity on most if not all days of the week. Physical activity can be accumulated in three 10 minute bouts of activity and could be just as effective as 30 minutes all at one time
Special Notes: This report is very similar to the Surgeon General's recommendation but it is significant because it looked at new science and was able to report that activity could be done in short bouts and still have significant health benefits. Many American's cite lack of time as a reason for not being physically active; this report demonstrated that with as little as 10 minutes at a time you could be more active.
Institute of Medicine (IOM) 2002
Recommendation: Adults should get at least 60 minutes of moderate physical activity each day.
Special Notes: The IOM recommendation of 60 minutes is to prevent weight gain and pertains to additional weight related health issues. Their recommendation for weight loss is 90 minutes a day. This recommendation was part of a large report that focused on recommendations for weight management. This recommendation should be considered complementary to the Surgeon General's recommendation.
American College of Sports Medicine and the American Heart Association 2007
Recommendation: Healthy adults under age 65 is for 30 minutes of moderate-intensity cardio 30 minutes a day, five days a week or 20 minutes a day, 3 days a week of vigorous cardio activity and for eight to 10 strength-training exercises, eight to 12 repetitions of each exercise, at least twice a week. They note that 60 to 90 minutes of physical activity may be necessary to lose or maintain weight loss.
Special Notes: The IOM recommendation of 60 minutes is to prevent weight gain and pertains to additional weight-related health issues. Their recommendation for weight loss is 90 minutes a day. This recommendation was part of a large report that focused on recommendations for weight management. This recommendation should be considered complementary to the Surgeon General's recommendation.
U.S. Health and Human Services 2008
Recommendation: This report recommends that adults should get at least 2 hours and 30 minutes each week of moderate effort aerobic activity and 2 days a week of strengthening activities.
Special Notes: This most recent report, published by the U.S. Federal Government incorporates the most recent reviews of science on the benefits of physical activity. 2 hours and 30 minutes a week is equal to 30 minutes five days a week. Physical activity can be accumulated as mentioned in previous sections.
What does it all mean?
Here are some of the basic take away messages from the recommendations:
Regular physical activity is important for health and disease fighting properties and there is lots of scientific proof to back this up.
Whether you accumulate your physical activity as 30 minutes a day for at least five days a week or 2 hours and 30 minutes throughout the week depends on what works best for you. Both recommendations support that you can accumulate your physical activity, but it needs to be in at least 10-minute bouts to get the benefits.
If your goal is to loose weight the higher numbers, 60 to 90 minutes, are the recommendation. However, if you have been inactive or are just starting you need to start with lower amounts and work up.
For health benefits:
Adults should engage in moderate-intensity physical activities for at least 30 minutes on 5 or more days of the week or get at least 2 hours and 30 minutes each week of moderate effort aerobic activity.
Adults may accumulate the recommended amount of moderate-intensity physical activity in ten minutes bouts throughout the day or week. But it is important to note that the evidence for doing this is that 10 minutes is the threshold for gaining the benefits.
Adults who are able to engage in vigorous-intensity physical activity can get health benefits in less time per week; 20 minutes 3 days per week.
Strength and flexibility activities should be performed twice a week.
For weight management and weight related issues:
Adults should engage in 60 to 90 minutes of moderate-intensity physical activity per day, and include strength and flexibility activities as well.
Moderate or vigorous intensity?
Intensity is referred to in most of the recommendations. The definitions below from the Center for Disease Control and Prevention are designed to help you understand what the various intensity levels mean. The right column of this page also has examples of activities and the intensity levels usually associated with them.
Intensity: Intensity refers to how much work is being performed or the magnitude of the effort required to perform an activity or exercise.
Moderate-intensity physical activity: On an absolute scale, physical activity that is done at 3.0 to 5.9 times the intensity of rest. On a scale relative to an individual's personal capacity, moderate-intensity physical activity is usually a 5 or 6 on a scale of 0 to 10.
Vigorous-intensity physical activity: On an absolute scale, physical activity that is done at 6.0 or more times the intensity of rest. On a scale relative to an individual's personal capacity, vigorous-intensity physical activity is usually a 7 or 8 on a scale of 0 to 10.
Common Special Considerations
If you have not been active in some time, start at a comfortable level and more activity as you go along. Don't be discouraged if you cannot do 10 minutes of physical activity at a time in the beginning. Start by doing what you can, and then look for ways to add more. Some activity is better than none and over time you can progress up to the recommendations. The more you do, the greater the health benefits and the better you'll feel.
If you have special medical considerations or concerns you should begin by talking with your healthcare provider about being physically active. Most conditions and chronic diseases recommend physical activity as part of good self-management techniques.
Over Age 65
Regular physical activity is essential for healthy aging. Adults aged 65 years and older gain substantial health benefits from regular physical activity, and these benefits continue to occur throughout their lives.
Key Guidelines for Older Adults
The following Guidelines are the same for adults and older adults:
All older adults should avoid inactivity. Some physical activity is better than none, and older adults who participate in any amount of physical activity gain some health benefits.
For substantial health benefits, older adults should do at least 150 minutes (2 hours and 30 minutes) a week of moderate-intensity, or 75 minutes (1 hour and 15 minutes) a week of vigorous-intensity aerobic physical activity, or an equivalent combination of moderate- and vigorous-intensity aerobic activity. Aerobic activity should be performed in episodes of at least 10 minutes, and preferably, it should be spread throughout the week. Increasing physical activity to even higher levels of intensity or being active for greater amounts of time may gain more extensive benefits.
Older adults should also do muscle-strengthening activities that are moderate or high intensity and involve all major muscle groups on 2 or more days a week, as these activities provide additional health benefits.
The following Guidelines are just for older adults:
When older adults cannot do 150 minutes of moderate-intensity aerobic activity a week because of chronic conditions, they should be as physically active as their abilities and conditions allow.
Older adults should do exercises that maintain or improve balance if they are at risk of falling.
Older adults should determine their level of effort for physical activity relative to their level of fitness.
Older adults with chronic conditions should understand whether and how their conditions affect their ability to do regular physical activity safely.
One size does not fit all
The source of the guidelines, the date the guidelines were made, the benefits to be gained if the guidelines are followed and the population that are intended for the guidelines are all factors that you should weigh as you consider if a recommendation or guideline is right for you. This review has looked at a few of the most commonly cited recommendations. Additional recommendations exist, made by a variety of organizations, like the American Heart Association or the American Diabetes Association; and for different ages, such as children, toddlers and older adults.
Whichever guideline you choose to follow. Remember to start slowly, progress gradually, listen to your body and be physically active regularly. Be healthy. Be active.
Liz McNett Crowl is a Health Community Specialist at Skagit Valley Hospital a Washington-based hospital specializing in http://www.skagitvalleyhospital.org/program-services/cancer-care/ Cancer Care, http://www.skagitvalleyhospital.org/program-services/orthopedics/ Orthopedic Care, http://www.skagitvalleyhospital.org/program-services/heart-center/ Cardiovascular Care and more.