The president has made three trips to Singapore this year for medical check-ups, raising questions over his health ahead of next year’s elections.
Mugabe says even the strength of his bones had recently shocked his doctors.
Addressing supporters at a rally in the northern town of Chinhoyi at the weekend, Mugabe said he thanked God for keeping him healthy.
Mugabe will be 94 next year when he stands for re-election, and last week his wife Grace urged him to name a successor.
But in comments carried by state media, Mugabe told supporters he wasn’t going anywhere.
And he said that those with ambitions to lead the party were divided along tribal lines.
Robert Mugabe: I’m Still Fit to Govern