Anytime Fitness Warners Bay confessed that it was responsible for this strange bout of purple mania.

“Yes the mysterious purple bikes around Warners Bay were ours,” the fitness chain said on social media.

“It was our quirky way of raising awareness about getting active this spring.”

The mystery began when purple bikes were locked up at several bike racks, while one was seen hanging from a street sign.

Topics likes a clever marketing idea, but we should make it clear that there’s no cash for comment in this column.

So you know this isn’t an ad, we’d like to point out that there’s plenty of ways to exercise without going to a gym.

But to be fair to the fitness chain, it made this point as well.

“Whether it’s kicking a footy at the park with your kids, walking along our beautiful foreshore or simply riding a bike – or you can pop in and see us at Warners Bay – it’s about getting active,” Luke from Anytime Fitness said.

“Come on Newcastle it's your move.”