On average, surveyed parents believed their children were engaged in moderate or vigorous physical activity for 146 minutes per day – but the real figure was only 24 minutes.
Researchers from Gateshead monitored the activity of 130 6-7 year olds through a portable recording device attached to the waist.
The results revealed that only 3% of boys and 2% of girls engage in enough physical activity – 60 minutes is recommended.
The parents' estimates were compiled using the Health Survey for England’s parent questionnaire and authors of the report feel that this tool is fundamentally flawed.
They said: ‘Public health surveillance of physical activity should not rely on this data.’
‘Levels of habitual physical activity in children are likely to be substantially lower than those reported in UK health surveys,’ they added.
Findings were published online in the Archives of Disease in Childhood.