Defending Olympic 50 and 100 metre freestyle champion Ranomi Kromowidjojo insists reports of a back injury were blown out of proportion by the media.

The Dutchwoman completed the 50 and 100m double at the London Olympics four years ago and is in Rio de Janeiro ready to defend her titles in Brazil.

However, there was concern for the 25-year-old after reports emerged of damage to one of her spinal discs during a weight training session.

Kromowidjojo, though, insists the issue is not as bad as feared and she is feeling in good shape ahead of the Games.

"Yes, I had a little bit of pain in my lower back but the media blew it all up," she told reporters after a training session at the Olympic Aquatics Stadium on Monday. 

"It wasn't an injury, it was just a case of having to be careful, it was just an irritation.

"I'm fine and feeling really good, great, and really looking forward to racing."

Kromowidjojo has vowed to do all she can to retain the gold in Brazil, but does not consider herself favourite to do so.

"I don't consider myself the favourite. I think Cate Campbell [of Australia] and her little sister [Bronte Campbell] and Sarah Sjostrom [Sweden] are really strong swimmers but I'm sure I'm going to fight for the gold medals," she added.

"When you're the favourite, like I was four years ago, all eyes were on me but now I think people in the Netherlands want to see me win the golds but it's not easy. It's harder than ever."