Manchester United boss Sir Alex Ferguson says he doesn't struggle to maintain his enthusiasm.

Ferguson will celebrate 25 years in charge at Old Trafford next month, but the 69-year-old is showing no signs of slowing down.

The renewal of his rivalry with Kenny Dalglish and the emergence of another young and vibrant United side have kept him energised and at the top of his game.

"It's pretty easy for me, because I'm usually surrounded by young people," said Fergie, in an interview with US radio station SiriusXM.

"I like young people, they give you an energy and enthusiasm and, matched with my own experience at the club, it's a good combination.

"So that makes it easy for me. I've been the manager for 25 years, so I've always got time on my side and always been able to look forward.

"It's a results industry and some coaches and managers are put under pressure from the day they take over. But we're able to look ahead, simply because nothing changes at United."