Speaking from the Swedish team's hotel in Eskilstuna, about 110 km outside Stockholm, Sjostrom told Reuters she would capitalise on the scheduling by taking on the additional event.

"I didn't know there was two days' rest after the 100m free final and before the 50 free started, so that obviously made me think about the decision I took before to only swim the 50," she said. "But since I have two days recovery between those events, it really opened up the opportunity to do both."

A four-time world champion in the 50m distance, Sjostrom initially had no interest in the 100m event. However, she reconsidered her decision to focus solely on the shorter race in Paris.

"I've been training for 50 for a few years and also I did the (100m) in the Rome Sette Colli competition in the end of June and I did much better than I thought I would, so that's also one of the reasons I guess why I decided to enter the 100 free," she explained.

Sjostrom, one of swimming's most decorated competitors with one gold, two silver, and one bronze Olympic medal, won her gold in the butterfly at the Rio Games and has yet to win Olympic gold in freestyle.

Preparing for her fifth Olympics, Sjostrom said she would not underestimate the competition as she aims for another Olympic medal in Paris, where the Games run from 26 July until 11 August.

"I'm just gonna try to do what I can and then we'll see how far that will get me, but of course I hope I will be one of those smiley faces on the podium."