According to court documents, Whidbey Island Bank won a judgment against the gym owners in December after they defaulted on a loan worth more than a million dollars.
The owners, M&M Fitness, had put the equipment up as collateral. On Tuesday, the bank seized that equipment.
Customers got the news when they arrived at the gyms to work out.
"I thought at first they were having a sale of old equipment or something, but that's obviously not the case," said Michael Austin, a member of the Gold's Gym in Marysville.
Gym owner Mike Moody posted on the Arlington gym's Facebook page earlier this month that his gym needed help and new members.
"The economy has been difficult for small businesses to succeed and the gyms were not immune," Moody wrote.
Some customers, including Kevin Roberts, are now out the money they paid for memberships.
"Ninety-nine dollars for 99 days," said Roberts of a membership he just bought for his wife. "She just did it yesterday."
A Gold's Gym corporate spokesman said that Tuesday's action does not affect the nine gyms in the Seattle area.