AILSA CHANG, HOST:
There is no shortage of science that says exercise is good for you. Studies show that it cuts the risks of diabetes, heart disease and cancer, and that it can alleviate depression or even boost immunity, so many countries have tried to coax people into being more active. And yet...
DEBORAH SALVO: Despite really good science, great interventions, good ideas for policy, the levels of physical inactivity globally haven't really improved.
CHANG: Deborah Salvo is a researcher at the University of Texas at Austin. She and her colleagues have been trying to understand why that is. NPR's Jonathan Lambert reports.
JONATHAN LAMBERT, BYLINE: Over the past two decades, health agencies around the world have tried to get people to exercise, but a new report says roughly 1 in 3 adults and 8 out of 10 adolescents don't get enough. Salvo and her colleagues have a hunch as to why that number hasn't really budged.
SALVO: It's possible that the messages that we're hearing in terms of every move counts, every single type of physical activity is good for you - they may not be resonating very well for a global public.
LAMBERT: She says that's especially true for the 84% of the globe that lives in low- and middle-income countries. Researchers found that in those countries, most of the physical activity comes from walking or biking for transport or from physical labor. Relatively few people are exercising in their free time, and that's especially true for women.
SALVO: If you're a woman and you're poor and you live in a poor country, and you compare that to a man and he's rich and he lives in a rich country, the gap is huge. It's humongous, and it's more than the sum of the parts.
LAMBERT: The research was published in Nature Medicine. R.M. Anjana is a physician and epidemiologist in Chennai, India. She wasn't surprised by the results.
R M ANJANA: In an economically advanced nation, people have discretionary time for this kind of activity, and they can choose to be healthy. In a country like India, most people are walking because they don't have cars. They don't have any other way.
LAMBERT: Technically, that counts as physical activity, but...
ANJANA: Is it good for health? Is it helping them? Not really. There's traffic. There's pollution. There's - you know, there's so many things.
LAMBERT: There are other barriers to exercise in places like India, too, she says, especially for women. For example, the gym.
ANJANA: Gyms are not even acknowledged as a place of physical activity for a woman. It's very man-centric. Or, in fact, there are things that say, oh, are you a girl who goes to a gym? That means, you know, you're someone who interacts in not a good way with men.
LAMBERT: So she says, be creative.
ANJANA: We can't just tell women, go for a walk, go to the gym. It's not culturally allowed to go to the gym, and you can't just tell people walk. It doesn't work that way. So what is it that we can do to encourage these women to get healthier?
(SOUNDBITE OF SONG, "TERI BAATON MEIN AISA ULJHA JIYA")
ASEES KAUR, RAGHAV AND TANISHK BAGCHI: (Singing in non-English language).
LAMBERT: For women and girls in her community, she designed a high-intensity dance class, choreographed to the latest Bollywood hits.
ANJANA: The minute people start hearing it, they start vibing to it.
LAMBERT: A 12-week trial of over a hundred girls in Chennai found that the program made a difference.
ANJANA: They start improving skeletal muscle mass. Their body fat goes down. Their eating pattern changes.
LAMBERT: Of course, a dance class may not be for everyone, and it's not going to solve the bigger issues that keep people from being active in healthy ways like unwalkable cities.
ANJANA: It's never going to be one-size-fits-all here, right? So different things could work in different regions.
LAMBERT: Scaling up those interventions would require countries to make physical activity a priority. Right now, it sits at the intersection, researchers say, of transportation, urban planning, sport, education. But because it's everyone's job, they say it's no one's responsibility. To get more people moving, the researchers say that may need to change. Jonathan Lambert, NPR News.
(SOUNDBITE OF SONG, "TERI BAATON MEIN AISA ULJHA JIYA")
KAUR, RAGHAV AND BAGCHI: (Singing in non-English language). Transcript provided by NPR, Copyright NPR.
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