Beating the nap-time blues:

Young children who are required to engage in day-time naps in childcare when they do not sleep are more likely to have disturbed sleep patterns that affect their behaviour and learning.

Professor Karen Thorpe, a psychologist from QUT's Institute of Health and Biomedical Innovation (IHBI), said it's time to consider the effect of enforcing strict daytime nap routines on small children.

"In Australia, approximately 50% of children aged 3-5 years attend some form of early childhood care and a day-time sleep/rest period is a prominent feature of their daily routines," she said.

"We've seen that the children that engage in day-time sleep are more likely to go to bed later and have more night waking than children who do not and their sleep disruptions can impact the entire family's functioning and well-being."

Professor Thorpe, who was named among this year's Financial Review and Westpac Group 100 Most Influential Women last week, said studies into sleep show that most children begin to grow out of day-time naps between the ages of three and five.

Being forced to lie down when sleep is no longer biologically required can lead to emotional and behavioural challenges for the child and childcare staff.

A reluctance to sleep may also mean the child is tagged as a "problem sleeper" despite following completely healthy sleep patterns.

"During the early childhood years children's sleep patterns are characterised by a gradual consolidation of sleep into the night-time and a reduction of sleep in the day-time," she said.

"While most studies agree that rates of day-time sleep decrease beyond age two and cease by the time children enter school, there remains considerable cultural variation in beliefs regarding when children should stop napping in the preschool years.

"Emerging evidence from studies examining the association of levels of the stress hormone cortisol with and childcare sleep practices suggest that children required to lie-down without alternative activities, when they do not sleep have higher; feelings of stress at night sleep-time."