With Christmas over, you've probably got a lot of cardboard around the house from all those presents.
But before you throw those boxes into your recycling bin, you may want to watch this video.
Luanga Nuwame (aka the Homemade Game Guru), has created an elliptical trainer out of his spare cardboard.
Blogging on makezine.com, Nuwame says he was inspired to make the machine after seeing hoards of adverts for fitness products on the television in the run up to the holiday season.
One week and 15 glued sheets of double-corrugated cardboard later, he finished his creation which he's since named the Cardboard-O-Flex.
"Truthfully, I was unsure if this first attempt would stay together once my full weight was applied," he says. "But it has and I couldn’t be happier."
So, before you ditch the cardboard (and renew that gym membership), why not get creative with those boxes? Just don't spill any water on them...