Greg Glassman, founder and chief executive of the competitive fitness company, apologised for a tweet at the weekend which he denied was racist.

Three women who have collectively won seven CrossFit Games titles and who have a combined Instagram following of 4.4 million were among the athletes to condemn Glassman's comments.

All three of them – Annie Thrisdottir and Katrin Davidsdottir of Iceland, and Tia-Clair Toomey of Australia - have competed at the International Weightlifting Federation (IWF) World Championships too, as there are strong links between CrossFit and weightlifting.

USA Weightlifting, which shares a community with CrossFit through shared gyms and memberships, said Glassman's actions were "abhorrent" in a statement issued by its chief executive Phil Andrews, who is also deputy director general of the IWF.

"We continue to support and believe the strength sport, weightlifting and CrossFit communities are welcoming, diverse and inclusive," said Andrews.

"We have enjoyed over a decade of collaboration, integration and growth together with that community.

"We implore CrossFit and the CrossFit community to come together as an inclusive movement as we all learn and listen to minority communities and understand what we all can do better.

"At USA Weightlifting we will continue to listen, and act."

More than 100 gyms had disaffiliated from CrossFit by yesterday, according to reports in the United States, where the company was created.

Glassman posted on Twitter on Saturday: "It's Floyd-19."

His comment was directed at the Institute for Health Metrics and Evaluation (IHME), an independent global health research organisation which has played a prominent role in forecasting for strategies to deal with the COVID-19 pandemic.

The IHME, based at the University of Washington, said racism and discrimination was a public health issue in need of an urgent response.

On Sunday (June 7), Glassman followed up by posting: "Your failed model quarantined us and now you're going to model a solution to racism?

"George Floyd's brutal murder sparked riots nationally.

"Quarantine alone is 'accompanied in every age and under all political regimes by an undercurrent of suspicion, distrust, and riots'.

"Thanks!"

Athletes, gym owners, social media followers and human rights groups expressed outrage, saying Glassman's comments were insensitive to the death of George Floyd.

Floyd, a black man, was killed on May 25 in Minneapolis, Minnesota when Derek Chauvin, a white police officer who has been charged with his murder, kneeled on his neck for nearly nine minutes.

There have been anti-racism protests all over the world in the aftermath of Floyd's death.

Among those who spoke out was Michael Muscato, who owns a CrossFit gym and is running for US Congress.

Muscato labelled Glassman's comments "tone deaf" and "pathetic," and urged Glassman to step down as chief executive.

Glassman apologised, saying he was trying to make a point about lockdowns to deter the spread of the virus, with which he does not agree.

"I, CrossFit HQ, and the CrossFit community will not stand for racism," he said on CrossFit's Twitter account.

"I made a mistake by the words I chose… my heart is deeply saddened by the pain it has caused. 

"It was a mistake, not racist but a mistake.

"Floyd is a hero in the black community and not just a victim.

"I should have been sensitive to that and wasn't. 

"I apologise for that.

"I was trying to stick it to IHME for their invalidated models resulting in needless, economy-wrecking, life-wrecking lockdown, and when I saw they were announcing modelling a solution to our racial crisis, I was incredulous, angry, and overly emotional.

"Involving George Floyd's name in that effort was wrong."

Toomey, the reigning CrossFit Games champion and also a Commonwealth Games weightlifting gold medallist in 2018, said she was "incredibly saddened, disappointed and frustrated with the actions and words of Crossfit HQ and in particular Greg Glassman.

"I'm deeply apologetic from the bottom of my heart to all the people who have had to witness this ignorance and the pain it causes," she said.

"A lack of acknowledgement and empathy for those who are fighting for basic human rights and equality is simply inexcusable and it's behaviour that we cannot stand for.

"My future with Crossfit is unclear and depends on the direction of HQ."

 There are about 13,000 CrossFit affiliate gyms or "boxes" across the world.