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Revised U.S. Department of Health and Human Services (HHS) recommendations on physical activity drew largely positive feedback from cardiologists and others in preventive medicine.
Key changes from the first edition released in 2008 -- announced Monday at the American Heart Association meeting in Chicago and published online in -- included:
- Elimination of the 10 minute threshold for physical activity to count toward meeting the recommendations
- Addition of a target of 3 hours of physical activity per day for children ages 3 to 5 years
- A longer list of health benefits accrued by physical activity, now including reduced risk of excess weight gain, improved cognition in youth and reduced risk of dementia later in life, and lower risk of a litany of cancer types
Adults remain advised to do 150 to 300 minutes of moderate exercise or 75 to 150 minutes of vigorous exercise each week along with muscle and strength training twice per week to achieve the most benefits, the same as in the first guideline released in 2008.
Brief Bouts
But the allowance for brief bouts to count toward the goal makes it "actually easier to achieve the recommendations in the physical activity guidelines," said Adm. Brett Giroir, MD, assistant secretary for health at HHS, who presented the new recommendations at the AHA meeting.
"It's not just a change of having more people meeting it artificially, I think it's going to empower people to say look all I have to do is walk up the stairs instead of not," he told 乌鸦传媒.
Sports cardiologist John Higgins, MD, MBA, of the University of Texas Health Science Center at Houston, agreed that the new advice can succeed in encouraging sedentary individuals to make small changes that add up.
"I think this has the potential to help people maintain weight, and in some cases, with changes in diet, lose weight," he said. "The more people know about benefits, the more likely they are to buy into exercise."
While those small changes won't reverse the obesity epidemic on their own, it is strong encouragement for all to move more, no matter how or when, commented Connie Diekman, MEd, RD, of Washington University in St Louis: "The process of getting Americans to move more is that, a process -- therefore any movement is a step in the right direction."
The HHS guidelines, which the AHA announced it will adopt as its official recommendations too, pointed out that evidence across many health benefits of physical activity show the biggest gains at the lowest levels. While benefits don't max out at any level, those who go from totally sedentary to a little active get a steep gain in life expectancy and health.
"If we can get people to start it, hopefully they'll continue that. If we get them into changing some behaviors, walk up a flight of stairs, park a little further away, start to do some of those things, then they'll add up. And then hopefully we're getting them to 150 [minutes per week]," Katrina Piercy, PhD, RD, of HHS in Rockville, Maryland, and first author on the guidelines told 乌鸦传媒.
If just a quarter of sedentary Americans got to the recommended activity level, 75,000 early deaths would be prevented, Giroir noted. "We know that physical inactivity is responsible for 10% of premature mortality."
There was no evidence that only 10-minute bouts count, but nor is there evidence that requirement has been holding people back, acknowledged William Kraus, MD, of the Duke University School of Medicine, who was an author on the science report that informed the guidelines.
Challenges Ahead
In fact, only about 1% of adults can correctly identify what amount of physical activity is recommended by the guidelines, said Don Wright, MD, MPH, deputy assistant secretary for health at HHS.
And there is some risk of unintended consequences from making people feel like they're doing better about exercise by doing the same things they've been doing. That was illustrated by a large-scale trial of wearable fitness trackers, noted Keith Fox, MD, of the University of Edinburgh, in an interview with 乌鸦传媒. "You know what it did? Increased weight. 'Oh, I've done well, I'd better go have something extra.'"
The key to these guidelines is going to be implementation at all levels, with a big portion falling to the healthcare team, argued Carl "Chip" Lavie, MD, director of the exercise laboratories at the Ochsner Heart and Vascular Institute in New Orleans.
In audience research and user testing by HHS, the most frequently reported barrier among people not meeting the guidelines was being too tired. Other stoppers were time, pain, chronic illness, and disability.
"As a physician, it's interesting to me that some of these barriers like pain may be rooted in medical causes," Wright said at the AHA session.
"We are uniquely positioned to help patients address the underlying medical issues and to help them understand that, while it may sound counterintuitive to the patients that don't feel well enough to get physical activity, doing so can actually boost energy, manage pain and help them manage their chronic condition."
Kraus urged healthcare professionals to ask patients about their physical activity and counsel them about it. "We spend a lot more time writing prescriptions for drugs that don't have 10% of the benefits that physical activity does."
HHS also has a campaign (called "Move Your Way," similar to the "My Plate" campaign for dietary recommendations) planned to target people who might be contemplating a change.
But it would be naïve to think healthcare professionals can do it all, noted Russell Pate, PhD, of Duke University in Durham, North Carolina, and chair of the National Physical Activity Plan alliance. "Fundamentally we need to effect profound change on the ground where the people are throughout the country."
Changes especially at the local level will be needed, such as mixed-use zoning, rehabilitation and upgrading of park facilities, encouraging local sports leagues, and supporting comprehensive school physical activity programs.
That the update tackles physical activity at a younger age than before may make a real difference, suggested Kyle Mandsager, MD, an electrophysiologist at the Cleveland Clinic who has been involved in physical activity research.
"Encouraging physical activity and developing healthful lifestyle habits at an early age likely has a greater long-term impact on obesity prevention," he told 乌鸦传媒.
But activity is just one component of tackling the obesity epidemic, noted Diekman, a past president of the Academy of Nutrition and Dietetics.
Diet is possibly even more important as a contributor to obesity, agreed Kim Williams Sr., MD, of Rush University Medical Center in Chicago and a past president of the American College of Cardiology.
"About one-fifth of weight loss that patients experience is due to improvements in their exercise program, and changes in calorie quality and content of the diet are about four times more powerful," he told 乌鸦传媒. "The few who do it with exercise more than diet are doing extreme endurance training, which is of course also helped by better nutrition."
The real test of endurance lies ahead, Pate suggested. "We need persistence because those things [population-level changes in health behaviors] are not going to happen quickly in many cases."