Don’t sit down in the middle of the woods. If you’re lost in the plot or blocked, retrace your steps to where you went wrong. Then take the other road. And/or change the person. Change the tense. Change the opening page.

The real problem is that the pain actually gets worse. You have created massive acidosis in your muscles so there is a huge quantity of hydrogen ions and the pH in your blood changes. For 15 minutes you lie there thinking, "God, this is really bad. I'm going to die. It has never been this bad before." And every time you think exactly the same thing. You have to lie to yourself by saying you're not doing a second set. Then, without moving for 15 minutes, almost to the second, I would roll over and think, "OK, I think I can do a second set now." During those sessions I have never felt more alive or so close to death.

There are days when I wake up and don't want to move, but you must show up!

I would try to keep myself going by inventing games, and I would sing songs, a song beginning with “A,” “Always.” “Because,” “Charmaine,” “Daisy,” go through the alphabet. ... I would try to remember the states in the United States of America.

Writing fiction is not “self-­expression” or “therapy”. Novels are for readers, and writing them means the crafty, patient, selfless construction of effects. I think of my novels as being something like fairground rides: my job is to strap the reader into their car at the start of chapter one, then trundle and whizz them through scenes and surprises, on a carefully planned route, and at a finely engineered pace.

Treat writing as a job. Be disciplined. Lots of writers get a bit OCD-ish about this. Graham Greene famously wrote 500 words a day. Jean Plaidy managed 5,000 before lunch, then spent the afternoon answering fan mail. My minimum is 1,000 words a day – which is sometimes easy to achieve, and is sometimes, frankly, like shitting a brick, but I will make myself stay at my desk until I’ve got there, because I know that by doing that I am inching the book forward. Those 1,000 words might well be rubbish – they often are. But then, it is always easier to return to rubbish words at a later date and make them better.