PureGym has apologised after one of its gyms likened its "workout of the month" to slavery.
The Facebook post, which has since been deleted, shared details of a workout called "12 Years of Slave" to "celebrate" Black History Month at the gym in Luton.
"Slavery was hard and so is this," the post said.
The workout included push ups, box jumps, burpees, and squats.
The post was branded "despicable" by social media users.
"Utterly insensitive and ridiculous," one Twitter user said.
Another wrote: "This is beyond tone deaf."
A third said: "I am absolutely disgusted by what I've seen.
"How dare you, and your employees, make an absolute mockery out of the pain felt by Black people.
"Black History Month is not a joke. Black people are not a joke. Stop making a joke out of our lives. Despicable."
A fourth wrote: "Someone needs to be held accountable for this and evidently anti-racist training is needed urgently across the corporation.
"They are a representative of YOUR brand, how you could let this happen is despicable."
In a statement, PureGym said it "apologises unreservedly" for the post.
"This post is wholly unacceptable, was not approved or endorsed by the company and was removed as soon as it was brought to our attention," it said.
"Each of our 271 gyms has its own social media channels which are run locally.
"We take this matter extremely seriously and are urgently investigating how and why this post was made."
Black History Month is an annual celebration of the history, achievements and contributions of black people in the UK.
First proposed in 1915 by American historian Carter G. Woodson, half a century after the Thirteenth Amendment abolished slavery in the United States, BHM has become a widespread celebration across the globe, including in the UK.
