Many of today's children cannot run as fast as their parents could, a new study of global fitness has found.
The findings, presented to the American Heart Association in Dallas yesterday, suggested an international decline in levels of cardiovascular fitness in youths.
Researchers analysed 50 studies on running fitness between 1964 and 2010 of more than 25 million children aged nine to 17 in 28 countries.
“Imagine you are racing over four laps of an Olympic track," Grant Tomkinson, who led the research at the University of South Australia in Adelaide, said.
"If you took the average child from 1975, transported them to today, put them against the current average child, they would beat them by almost a lap.”
He added: "In fact, about 30% to 60% of the declines in endurance running performance can be explained by increases in fat mass."