FOR athletes governed so acutely by precision, swimmers often fall victim to the unpredictability of their body.
Illness and elite swimming are unwanted bedfellows, as Melanie Schlanger can attest.
The Nambour-born speedster is about to contest her second Olympics, hoping to add to the 4x200m freestyle gold and 4x100m freestyle bronze medals she won at the 2008 Beijing Games.
This time she will also compete in an individual event, having won the 100m freestyle at the Olympic trials earlier this year.
The road to London, however, has been physically and mentally perilous for the 25-year-old.
Not long after returning from Beijing, she contracted a glandular fever-like illness, cytomegalo virus.
Unable to perform at her optimum, despondency and frustration set in.
In 2010, she walked away from the sport emotionally spent.
"That was probably the lowest of lows in terms of my swimming," she said.
"I didn't want anything to do with the sport again.
"To come back not too long after quitting with actual love of the sport again is something I didn't expect.
"My performances have really reflected how much I'm enjoying training and competing again.
"I'm definitely proud of myself, on the point of view that I'm coming from basically quitting to exceeding my expectations in almost every way."
Schlanger's metamorphosis back into a world-class athlete came after Josh Santacaterina, a work colleague at Royal Brisbane Hospital and former 25km open-water world swimming champion, convinced her to do some social swimming.
From her first session, her love for the sport was rekindled.
"To be honest, if you told me back than (when she quit) I'd be in the Olympic team in 2012, I probably would have laughed at you," Schlanger said.
"To come back, and I haven't really had any concerns in that area (her health), it's a massive turnaround."
You can say that again.
Schlanger has not only elevated herself into an individual-event national champion, she is also a definite medal chance in the 100m freestyle in London.
She is ranked No.6 in the world in the event, her season-best time of 53.74sec coming at the NSW open in February.
Holland's Ranomi Kromowidjojo, the reigning 100m freestyle world championship bronze medallist, is the quickest in the world this year by a fair margin after clocking 52.75sec in April.
Schlanger fancies her chances of medalling.
"I'm expecting to swim better than I have, and hopefully that will be good enough to do Australia proud," she said.
"I figure the first step is to make the final … after that a medal is not far outside my reach in terms of my personal best time and world ranking at the moment.
"It definitely puts me in contention for a medal, if I can actually put it together on the day."
- Age: 25
- Born: Nambour
- Lives: Brisbane
- Trains: Commercial Swimming Club
- Olympic record: 4x200m freestyle gold and 4x100m freestyle bronze medallist at 2008 Beijing Olympics
- In London: 100m freestyle contender and member of the 1`00m and 200m freestyle relay teams