Children worldwide less fit than their parents were

Children around the world can't run as far or as fast as their parents could at their age, new research finds. According to new research presented at the American Heart Association's annual meeting, children's fitness levels are on the decline, the BBC reports. Researchers from the University of South Australia analysed data involving 25 million children in 28 countries and spanning 46 years. Findings showed that children today run a mile 90 seconds slower than their counterparts did 30 years ago -- and this could spell bad news for their health down the road. "If a young person is generally unfit now, then they are more likely to develop conditions like heart disease later in life," lead researcher Dr Grant Tomkinson told the BBC. "In fact, about 30% to 60% of the declines in endurance running performance can be explained by increases in fat mass." While children in Western countries showed the most dramatic differences, some parts of Asia like South Korea, mainland China and Hong Kong are also seeing this phenomenon, the findings showed. To stay healthy, children need to exercise -- by biking, walking, or running around the playground -- at least an hour a day, and research has shown that small chunks work just as well as one session.