Crocodile shows up at water aerobics class.

This is precisely why I don't exercise. Item!

A water aerobics class in northern Australia had a good reason to skip the morning workout: a crocodile was busy using its pool.

The 5-foot-long invader was spotted by workers Tuesday at the Howard Spring Holiday Park, outside Darwin, while they were cleaning the trailer park's pool for a class frequented by tourists, Australia's Northern Territory News reported.

"I bent down to the water and there it was, staring at me, less than 3 meters (10 feet) away," the park's manager, Geoff Thompson, told the newspaper.

At least one person did manage a workout.

"The crocodile gave one of the crocodile management rangers a bit of a runaround, having to chase it around the pool," Northern Territory Parks and Wildlife senior ranger Tom Nichols said in a statement.

Rangers believe the croc slipped in under a fence.