One of Us: The Story of Anders Breivik and the Massacre in Norway by Ǻsne Seierstad:
He had three cells at his disposal. The first was a living cell with a bed, a place to eat and cupboard. The second was a work cell with a typewriter firmly stuck to a table. The third was a workout cell with a treadmill. He was not satisfied with the running machine. He was not a long-distance runner, he had told the prison, but a body builder. Naturally, free weights were out of the question on security grounds, but already on his very first week in prison he had devised ways of toning his body with the help of his own body weight. Then he lost his motivation. Through the autumn of 2012 he lost his spark. ‘A sense of resignation,’ his lawyer called it.