Justin Bieber: I'm just human

Justin Bieber has seemingly claimed working out was part of the reason for his onstage collapse last week.

The Canadian singer was mired in controversy after he arrived a reported two hours late for a concert in London, UK, and was taken ill while on stage several days later.

The star was taken to hospital after becoming breathless while performing last Thursday and posted a picture of himself in a medical bed on the Internet. He was also seen lashing out at a photographer while leaving his hotel. Justin admits it was a tough seven days but has assured his fans he's doing well.

"It was a hard week. I worked out every morning and had to do a big show in the evening," he told German newspaper Bild.

"When people point a camera in your face the whole day and scream ugly things in your face… I'm just human. I'm far away from home; I miss my folks, my siblings, my friends.

"I don't regret anything. I've learned from every single mistake I made."

There have been fears the young star is going off the rails after he got caught up in a string of scandals since splitting from Selena Gomez last year.

He has tried to allay fears about his personal life, claiming music and his fans are still his number one priority.

"I try to stay humble. Honestly, I'm still the boy from Canada who just wants to share his music with the world," he explained.

"I wanna have a family one day. But at the moment I'm just grateful that I can do want I love to do."

Justin will continue his The Believe Tour in Portugal this week, but has cancelled one of two dates in Lisbon due to "unforeseen circumstances".

Ticket holders have been offered a refund, although further clarification about Justin's withdrawal hasn't been offered.