A new edition of the federal government’s “Physical Activity Guidelines” — the first update in 10 years — was released on Monday.

You won’t find a lot of changes in the new guidelines, but its publication offers all of us a good reminder of how important physical activity is for our health.

The guideline’s central message can be summarized in four simple words:

Sit less. Move more.

I’m often struck by how people willingly turn to unproven dietary supplements or other questionable products and “therapies” to enhance their health or slow down the aging process while doing little or nothing to keep physically active.

Yet exercise is known as one of the best “medicines” around. As the head of Great Britain’s Academy of Medical Royal Colleges has said, “If physical activity was a drug it would be classed as a wonder drug, which is why I would encourage everyone to get up and be active. “

A long list of benefits

Exercise’s known preventive benefits alone should be enough to persuade everybody to get moving. For children and teenagers, regular physical activity can improve mental skills, bone health and heart health, as well as lower the risk of depression. For adults, it helps reduce the risk of certain cancers, dementia, heart disease, stroke, high blood pressure, type 2 diabetes and depression, including postpartum depression among pregnant women. For older adults, regular physical activity also lowers the risk of falls and injuries from falls.

And physical activity can help people of all ages maintain a healthy weight.

More recently, however, researchers have also discovered that physical activity can help people manage many of the chronic health conditions they already have. Exercise can sometimes reduce the pain associated with osteoarthritis, for example, and keep high blood pressure and type 2 diabetes from progressing. It can also ease the symptoms of anxiety and depression, and improve cognition for individuals with dementia, multiple sclerosis and Parkinson’s disease.

Yet, despite all these benefits, only 26 percent of men in the United States, 19 percent of women and 20 percent of adolescents meet the recommended levels of physical activity.

The consequences of that low adherence are immense. Almost $117 billion of the United States’ annual health care expenditures are the result of our sedentary lifestyles, the guidelines point out.

Low levels of physical activity are also linked to 10 percent of premature deaths in the U.S.

Key changes and recommendations

One of the most notable changes in the updated guidelines is the elimination of the requirement that physical activity only “counts” for adults when done in bouts lasting at least 10 minutes. The new guidelines say all activity accounts.

Another major change involves young children. The old guidelines offered physical activity recommendations for children as young as 6. The new guidelines recognize that children aged 3 through 5 years need to be physically active, too.

Here are the new guidelines’ key recommendations:

For Preschool-Aged Children

Preschool-aged children (ages 3 through 5 years) should be physically active throughout the day to enhance growth and development. [The aim should be at least 3 hours of active play a day.]

For Children and Adolescents

Children and adolescents ages 6 through 17 years should do 60 minutes (1 hour) or more of moderate-to-vigorous physical activity daily:

• Aerobic: Most of the 60 minutes or more per day should be either moderate- or vigorous-intensity aerobic physical activity and should include vigorous-intensity physical activity on at least 3 days a week.
• Muscle-strengthening: As part of their 60 minutes or more of daily physical activity, children and adolescents should include muscle-strengthening physical activity on at least 3 days a week.
• Bone-strengthening:As part of their 60 minutes or more of daily physical activity, children and adolescents should include bone-strengthening physical activity on at least 3 days a week.

For Adults:

Adults should move more and sit less throughout the day. Some physical activity is better than none. Adults who sit less and do any amount of moderate-to-vigorous physical activity gain some health benefits.

For substantial health benefits, adults should do at least 150 minutes (2 hours and 30 minutes) to 300 minutes (5 hours) a week of moderate-intensity, or 75 minutes (1 hour and 15 minutes) to 150 minutes (2 hours and 30 minutes) a week of vigorous-intensity aerobic physical activity, or an equivalent combination of moderate- and vigorous-intensity aerobic activity. Preferably, aerobic activity should be spread throughout the week.

Additional health benefits are gained by engaging in physical activity beyond the equivalent of 300 minutes (5 hours) of moderate-intensity physical activity a week.

Adults should also do muscle-strengthening activities of moderate or greater intensity and that involve all major muscle groups on 2 or more days a week, as these activities provide additional health benefits.

For Older Adults

The key guidelines for adults also apply to older adults. In addition, the following key guidelines are just for older adults:

• As part of their weekly physical activity, older adults should do multicomponent physical activity that includes balance training as well as aerobic and muscle- strengthening activities.
• 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.
• 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.

For Women During Pregnancy and the Postpartum Period

Women should do at least 150 minutes (2 hours and 30 minutes) of moderate-intensity aerobic activity a week during pregnancy and the postpartum period. Preferably, aerobic activity should be spread throughout the week.

Women who habitually engaged in vigorous-intensity aerobic activity or who were physically active before pregnancy can continue these activities during pregnancy and the postpartum period.

Women who are pregnant should be under the care of a health care provider who can monitor the progress of the pregnancy. Women who are pregnant can consult their health care provider about whether or how to adjust their physical activity during pregnancy and after the baby is born.

For Adults with Chronic Health Conditions or Disabilities:

Adults with chronic conditions or disabilities, who are able, should do at least 150 minutes (2 hours and 30 minutes) to 300 minutes (5 hours) a week of moderate-intensity, or 75 minutes (1 hour and 15 minutes) to 150 minutes (2 hours and 30 minutes) a week of vigorous-intensity, aerobic physical activity, or an equivalent combination of moderate- and vigorous-intensity aerobic activity. Preferably, aerobic activity should be spread throughout the week.

Adults with chronic conditions or disabilities, who are able, should also do muscle-strengthening activities of moderate or greater intensity and that involve all major muscle groups on 2 or more days a week, as these activities provide additional health benefits.

When adults with chronic conditions or disabilities are not able to meet the above key guidelines, they should engage in regular physical activity according to their abilities and should avoid inactivity.

Adults with chronic conditions or symptoms should be under the care of a health care provider. People with chronic conditions can consult a health care professional or physical activity specialist about the types and amounts of activity appropriate for their abilities.

FMI: You’ll find the new “Physical Activity Guidelines” on HHS’s website. For tips and information (including videos) for getting you and your family more physically active, go to the HHS’ “Move Your Way” website.