Parents, schools and community groups can all help kids on their way to 60 minutes exercise a day." Image caption Children are advised to do at least an hour of vigorous activity every day 
 
 Many children cannot run as fast as their parents could when they were young, a study of global fitness says. An analysis of studies on 250 million children around the world... (Associated Press) 
 
 On average, it takes children 90 seconds longer to run a mile than their counterparts did 30 years ago. The American Heart Association, whose conference featured the research on Tuesday, says it's the first to show that children's fitness has declined worldwide over the last three decades. He says exercise must be something that "makes you sweat" and is "sustained and dynamic" to promote cardiovascular fitness. Lead researcher Dr Grant Tomkinson of the University of South Australia's School of Health Sciences said: "In fact, about 30% to 60% of the declines in endurance running performance can be explained by increases in fat mass." Researchers analyzed 50 studies on running fitness _ a key measure of cardiovascular health and endurance _ involving 25 million children ages 9 to 17 in 28 countries from 1964 to 2010. The decline is seen in boys and girls and across all ages from nine to 17 years, and is linked to obesity, with some countries faring worse than others.
– Today's children are the most sedentary generation in history and they would be easily trounced in a race with younger versions of their parents, a new study finds. Researchers—who looked at data involving millions of children in 20 countries over more than 40 years—found that today's young people run a mile around 90 seconds slower than their counterparts did 30 years ago, reports the BBC. Children are, on average, 15% less fit than their parents were, and the decline is seen for both boys and girls and for all ages between 9 and 17, the AP notes. Fitness has been dropping by around 5% a decade, the study found, and while the decline is slowly leveling off in Europe and North America, fitness is still going downhill fast in China and other parts of east Asia. Researchers say obesity and sedentary lifestyles are probably playing the biggest role in the fall in fitness—and they warn that unfit young people will be unhealthier later in life. Experts recommend that children over 6 get at least an hour of moderately vigorous activity throughout the day, but the World Health Organization estimates as many as 80% of the world's young people aren't getting the necessary exercise.