The steadily shrinking backyard in Australia could be having an effect on how much exercise children get, new research suggests.

A study by researchers at the University of Queensland found children who have access to "fixed" play equipment, such as swings and slides, were much more likely to meet national physical activity guidelines.

UQ School of Public Health researcher Katrina Moss said the study suggested there was a direct link between the type of play equipment children had access to and their level of physical activity.

Children with regular access to fixed play equipment at home or in a nearby park have much higher rates of physical exercise. Credit:Fairfax

"The combination of equipment matters, and fixed equipment is the kind of equipment that might get kids moving a bit more," Dr Moss said.