BORING, safety-first measures have killed off the fun in children's playgrounds, according to a new study that found bringing back old-fashioned equipment improves children's activity levels.

Resurrecting play materials could ease the country's childhood obesity crisis, said the university study titled "Popping the Bubble Wrap", which found creative equipment boosted activity and developed social skills.

Sydney University Health Sciences professor of occupational therapy Anita Bundy said unimaginative and play-safe public and school playgrounds were driving children indoors.

"There are not enough things that make kids want to get active," Professor Bundy said.