Athlete protests and political messages will remain banned at the Olympics, the IOC said Wednesday, after a survey found that a majority of competitors were in favour of keeping the ban in place.

That means raising a fist on the podium — like American sprinters Tommie Smith and John Carlos famously did at the 1968 Mexico City Olympics — or taking a knee would still risk punishment at the Tokyo Games this year.

The IOC said it surveyed more than 3,500 athletes over the past year and that 70 per cent said it was "not appropriate to demonstrate or express their views" on the field of play or at the opening or closing ceremony.

The survey also showed 67 per cent of respondents disapproved of podium demonstrations.

The IOC has not said what consequences athletes may face for protesting, but a "proportionate" range of punishments will be drafted before the games, said Kirsty Coventry, who represents athletes on the IOC executive board.

Smith and Carlos were both expelled from the 1968 Olympics after their salute.

Upholding Rule 50 of the Olympic Charter, which prohibits any "demonstration or political, religious or racial propaganda" at the games, puts the IOC at odds with Olympic officials in the United States.

The U.S. Olympic and Paralympic Committee said in December it will not take action if athletes raise their fists or kneel during the national anthem at their event trials before Tokyo.

The American Olympic body, which inducted Smith and Carlos into its Hall of Fame in 2019, eased its stance after athletes asked for the right to express themselves on racial and social justice issues.

While the USOPC guidelines allow athletes to wear apparel showing phrases such as "Black Lives Matter," the language is more limited in the IOC guidance published Wednesday.

Approved words on T-shirts and elsewhere in Tokyo are "peace, respect, solidarity, inclusion and equality," the IOC said.

Coventry, a former Olympic swimming champion who is now sports minister in Zimbabwe, said the survey and research conducted by the IOC Athletes' Commission was guided by independent experts on human rights and social sciences.

The IOC research consulted officially recognized athlete panels from national Olympic committees and sports governing bodies — a process that restricted input from activist athletes.

Other concessions agreed Wednesday include adding references to "inclusion and equality" in the Olympic Oath read at the opening ceremony in Tokyo on July 23.