The BBC presenter Andrew Marr has said he is "lucky to be alive" in his first television appearance since suffering a stroke three and a half months ago.

Marr, 53, told viewers of his flagship Sunday morning political show that he found walking difficult and his left arm "isn't much good" but his voice and memory were unimpaired.

He revealed that he suffered the stroke the morning after a rigorous session on a rowing machine and blamed overwork and excessive exercise for what happened to him.

"I had a major stroke. I'm frankly lucky to be alive. I had been heavily overworking – mostly my own fault – in the year before that," he said.

"I'd had two minor strokes, it turned out, in that year – which I hadn't noticed – and then I did the terrible thing of believing what I read in the newspapers, because the newspapers were saying what we must all do is take very intensive exercise, in short bursts, and that's the way to health.

"Well, I went on to a rowing machine and gave it everything I had, and had a strange feeling afterwards – a blinding headache, and flashes of light – served out the family meal, went to bed, woke up the next morning lying on the floor unable to move.

"And what I'd done, I'd torn the carotid artery, which takes blood into the brain, and had a stroke overnight – which basically wipes out a bit of your brain."

He was in hospital for nearly two months and said he still has a lot of physiotherapy to do, describing his walk as an "elegant hobble".

The BBC political editor, who is married to the journalist Jackie Ashley and has three children, was considered fit before his stroke, enjoying long-distance running.

Marr pre-recorded interviews with the Conservative former cabinet minister Lord Parkinson and the Labour peer Lady Kennedy on Saturday at Broadcasting House but the live section of the programme which bears his name continues to be hosted by guest presenters. He told his replacement on Sunday, the newsreader Sophie Raworth, that he needed to concentrate on his intensive physiotherapy before he would be able to return full-time but said that he was determined to do so.

"I'm going to be taking your chair I'm absolutely sure, when I'm ready," he said. "I'm certainly coming back."