BBC presenter Andrew Marr has made his first television appearance since suffering a stroke three and a half months ago.
Marr told viewers of his Sunday morning current affairs show that he was "frankly lucky to be alive" after what he had been through.
He said that walking was still difficult and his left arm "isn't much good yet" but his voice and memory were unimpaired.
He blamed a combination of 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 onto 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.
"In my case, luckily not my voice or memory or anything like that, but the whole left hand side of my body, which is why I'm still not able to walk fluently - I do a kind of elegant hobble is the best I can manage; my left arm isn't much good yet. I've got a lot of physio still to do."
Marr pre-recorded interviews with the Conservative former Cabinet minister Lord Parkinson and the Labour peer Baroness Kennedy yesterday at Broadcasting House.
The live section of the programme continues to be hosted by guest presenters, with news reader Sophie Raworth standing in today.
Marr assured her however that he remained determined to return to full-time duties.
"The only way through is intensive physio and doing a lot of it. And I'm now in the period where if I really concentrate on the physio, I will get better, and if I don't, I won't. Which is why I'm not back trying to do the job full-time, I have to say," he said.
"I'm going to be taking your chair I'm absolutely sure, when I'm ready. I'm certainly coming back. I've got a lot more to say about it all, but I'm going to wait until I've gone through the physio to do so."