Emeritus Pope Benedict XVI remains "lucid" at nearly 90 and has kept his "great sense of humour", his personal secretary Monsignor Georg Ganswein said on Thursday.
"Pope Benedict is an extremely alert old man," Ganswein told journalists at a conference in Rome on fair play and tolerance in sport and everyday life.
"He still has his innate sense of humour and only has difficulty walking," Ganswein said.
"He is a great and inspiring figure to me," Ganswein added.
Benedict, who will be 90 on 16 April, served as pope between 2005 and 2013, when he became the first head of the Catholic Church to resign in seven centuries, saying he no longer had the strength of mind or body to carry on.
However his health appeared to improve after he stepped down and moved into a former convent in the grounds of the Vatican to lead a life of "prayer and contemplation".
He walks with a frame and has stopped writing books but enjoys playing the piano, listening to music, reading, corresponding and receiving visitors, according to Ganswein.
Ganswein, who still plays an active role in the Vatican, lives with Benedict and also works for Pope Francis as prefect of the papal household.
Francis, 80, was elected pontiff in March 2013 shortly after Benedict abdicated.
