A recent WHO study found that Bangladeshi boys, aged between 11 and 17 years, made improvement in their daily activities.
It noted that countries showing the most improvement in activity levels among boys were Bangladesh (from 73 percent to 63 percent), Singapore and Thailand (78 to 70), Benin (79 to 71) and the US and Ireland (71 to 64).
Globally, around 80 percent adolescents do less than 60 minutes of activity per day – the minimum daily recommendation, reports UN news. The lack of exercise among adolescents across the world risks seriously compromising their health into adulthood, the UN said.
According to the study, the Philippines had the highest inactivity levels among boys, at 93 percent, while in South Korea, researchers found that 97 percent of girls failed to do enough exercise.
In gender terms on average, 85 percent of girls failed to do enough globally, only slightly worse than boys (78 percent).
"From 2001 to 2016 we found that there's been no improvement in patterns of activity in this age group … one hour out of their lives each day to be physically active and to get a health benefit from being physically active," said the WHO study co-author Dr Leanne Riley.
"That can be made up of different small chunks of their time, anything that adds up to 60 minutes."
Insisting that physical activity need not be overly strenuous or vigorous for it to be beneficial, Dr Riley explained that jogging, walking, cycling or "just trying to be active" can all make a positive difference.
In the long-term, failing to do enough exercise leaves people vulnerable to a range of non-communicable and preventable illnesses, WHO has repeatedly warned.
These non-communicable diseases include heart disease, high blood pressure, diabetes, breast and colon cancer.
An additional benefit of physical activity is improved mental health, Dr Riley insisted, highlighting that exercise also promotes learning, delays the onset of dementia and can help maintain a healthy weight.
"If they do it… they're likely to be healthier adults too," said the WHO study lead co-author Dr Regina Guthold, insisting on the importance of establishing healthy habits early on.
The difference between the amount of exercise between boys and girls was greater than 10 percent in almost a third of countries in 2016, and this trend became more pronounced in almost three-quarters of nations surveyed between 2001 and 2016.
Under the 2030 Global Goals Agenda for Sustainable Development adopted in 2015 by the international community, governments agreed to a 15 percent improvement in activity levels by 2030.
"We are off-track," Dr Guthold said. "This target will not be met if these trends continue."