Sailing: Griselda Khng and Sara Tan's hefty challenge

49erFX sailors Sara Tan (left) and Griselda Khng find maintaining their weight a challenge, as they burn about 1,300 calories during each training session. ST PHOTO: LIM YAOHUI

They have sailed across the world and competed in various continents, from Europe to South America. But for Olympic sailors Griselda Khng and Sara Tan, their biggest challenge so far lies in the seemingly simple task of gaining weight.

The pair, who will represent Singapore at the Rio Olympics in the 49erFX skiff, have struggled to put on the kilos in the last few years to ensure that they reach the optimum weight and keep the boat as flat as possible in the water. The flatter the boat, the faster it goes in a straight line. The 49erFX is making its Olympic debut this year.

Said skipper Khng, 24: "When we first started, we were extremely light and throughout the years, it's been difficult for us to gain mass. These small, little things can really make a difference."

For optimum performance, the ideal weight of sailors on the 49erFX rig should range between 120kg and 130kg. Both Khng and Tan now weigh 60kg and 72kg respectively, for a combined total of 132kg.

Khng added 14kg to her 1.55m frame in the last two years, while the 1.72m tall Tan reached her target weight only in March.

If bulking up was not difficult enough, Tan, 25, said maintaining her weight was just as tough.

"We burn about 1,300 calories every training session and I can feel the slight weight loss," she said. "As athletes, we're always burning calories and our body is used to it.

"To make up for this, we consume about six meals a day which add up to about 4,000 calories. The meals are big portions and it was quite difficult to keep that up at first."

Besides a strict diet of mostly fish or beef, which provides them around twice the recommended calorie intake of a regular woman (1,940), the pair also hit the gym six times a week. This is on top of the six sailing sessions weekly.

The pair, who finished eighth in the Sailing World Cup in England last week, feel all their efforts will be worth it come Rio. Said Tan: "We hope to be in the top 10 before the final day and make it into the medal race. That's our target."

Along with the 2015 SEA Games gold-winning pair, seven other sailors will sail for the Republic in August - making it the nation's biggest-ever Olympic sailing team.

They consist of laser sailor Colin Cheng, Elizabeth Yin in the laser radial, the women's 470 pair of Jovina Choo and Amanda Ng, the Nacra 17 pair of Justin Liu and Denise Lim, and Leonard Ong in the RS:X.

Minister for Community, Culture and Youth Grace Fu, who went out to sea yesterday to watch the sailors train at the National Sailing Centre, said: "We're very glad to see this young pipeline of sailors. It speaks well about the future of sailing in Singapore."

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A version of this article appeared in the print edition of The Straits Times on June 17, 2016, with the headline Sailing: Griselda Khng and Sara Tan's hefty challenge. Subscribe