The report included 4500 children aged eight to eleven.
In their investigation, scientists compared time spent in front of screens, physical activity and sleeping habits.
Kids who met the recommended guidelines set by the Canadian Society for Exercises Physiology showed improvements in cognitive ability. The guidelines include nine to eleven hours of sleep, one hour of physical activity a day and less than two hours on screens.
Researchers note that even by making changes to poor habits could improve memory.
"Evidence suggests that good sleep and physical activity are associated with improved academic performance, while physical activity is also linked to better reaction time, attention, memory and inhibition," says lead study author, Jeremy Walsh, from the CHEO Research Institute in Ottawa, Canada.
Alarmingly, in the US, only one in 20 children in the USA met all three guidelines. Meanwhile nearly one in three met none of them. It's still not clear whether statistics are similar in Australia.
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