The former world champion runner said she had used her savings to try to keep the gym afloat but had been unable to do so.
The Liz McColgan Health Club, in Carnoustie, Angus, employs six people, all of whom were being informed about the development.
The gym offered personal training and physiotherapy services, and the facilities were available for use by customers staying at McColgan's holiday homes.
McColgan, 48, who won her Olympic medal in the 10,000 metre event at the Seoul Games in 1988, made reference to the "difficult personal circumstances" of her recent divorce from husband Peter.
A statement said: "I can confirm the sad news that Liz McColgan Health Club Company is now bankrupt.
"For the last few years, through difficult personal circumstances of my divorce, I have put every penny of my savings into trying to keep the company afloat. I am now at the stage when I am no longer able to continue to do so.
"I broke the news today to our six staff and I would like to thank them and our members for their loyalty and support."
McColgan, from Dundee, is understood to be spending time with family following the announcement.