Nigerian presidential candidate Bola Tinubu jumped on an exercise bike to prove he is fit following social media claims on his health.
Mr Tinubu, of the governing All Progressives Congress (APC), also dismissed claims that he had withdrawn from the presidential race.
Nigerians will vote for a news president in February.
He tweeted: “Many have said I have died; others claim I have withdrawn from the presidential campaign.”
“I am strong, I am healthy and I am ready to serve Nigerians from day one.”
Ahead of the presidential elections, focus will be on the 70 year old’s health as he canvasses for votes.
Last year, he spent three months in London for a knee injury and there are other concerns about an undisclosed ailment.
Mr Tinubu’s main rival for the presidency is 75-year-old Atiku Abubakar. Earlier this year, Mr Abubakar’s team had to quash rumours about his health.