PYEONGCHANG, South Korea, Feb 19 (Reuters) - As if flying off a steep slope at 90km an hour wasn't enough to contend with, ski jumpers used to have to worry about their weight, but a rule change has all but removed eating disorders from the sport, a senior official told Reuters on Monday.
Austrian Walter Hofer, Race Director for Ski Jumping at the International Ski Federation (FIS), undertook research over a decade ago that discovered a simple way to remove the need for athletes to starve themselves.
"In the late 90s we had in our sport the so-called 'lightweight issue' where athletes tended to reduce their weight in order to get a better performance on the jumping hill, and we couldn't get rid of it," the 63-year-old Hofer said.
"We couldn't find any solution that worked when you see the jumper as a human being, as a biological system."
Hofer gave up trying to find the answer in biology and turned instead to physics, creating a reference jump in a wind tunnel to see how the distance could be manipulated by changing both the weight of the jumper and the length of their skis.
"The basic was 70 kilos and with that you jumped 120 metres. Then we started to go one kilo up, and the very same jump was 2.5 metres shorter.
"Then we reduced one kilo and the jump was 2.5 metres further, so there was a relationship between one kilo and 2.5 metres in distance," he explained.
"We fixed the kilos at 70 and started to manipulate the ski length. That gave us the idea to use the athlete's height and body weight, the so-called BMI (body mass index), and then we defined the ski length for each athlete," he said.
Hofer had found a formula that could be applied across the board, removing the need for athletes to worry about what or how much they ate. The new rules were introduced for the 2004-05 season.
Norwegian ski jumper Anders Bardal, a few years into his career when the changes came about, told Reuters of the problems he experienced trying to manage his weight.
"For me it was a bit of a problem to keep it (my weight) up. During the winter it's quite hectic, travelling a lot, not that good with eating, you're losing a bit of weight for sure," said Bardal, who won Olympic bronze medals in 2010 and 2014.
"Some athletes are also fighting a bit to get down, because the lighter you are the longer you can fly."
Regardless of the new rules, athletes still have to be responsible about their weight, something Bardal, who is in Pyeongchang working for broadcaster Eurosport, says is part of the price of success.
"No athlete who wants to fight to be the best could do this without sacrificing that kind of thing. You have to be the best in everything, in every part - in physical training, in eating, every part," he said.
For Hofer, the rule change has been a resounding success, and conditions like anorexia nervosa are a thing of the past in the sport.
"It doesn't make any sense any more to reduce the weight, because we reduce the skis. There's a table now so you can see, centimetre for centimetre, what kind of ski length the athlete is allowed to use," he said.
"So an athlete can never be too light - but he can have skis that are too long."
Reporting by Philip O'Connor, editing by Ed Osmond