When the men's and women's lightweight double sculls rowing event began on Sunday, it marked the beginning of the end of an era as weight classes are set to disappear from the Olympic rowing program after the Paris Games.

Introduced in 1996, the discipline has been under threat for years as the International Olympic Committee (IOC) seeks to restrict weight divisions to weightlifting and combat sports, and the curtain will finally come down after the finals on Aug. 2.

"Thomas Bach has come out and said you will only have weight categories where there's a risk, like boxing," said Michelle Carpenter, CEO of Rowing Ireland. "He said you don't have short basketball players, and so we're losing lightweight rowing."

The removal of lightweight rowing is a particular blow for the Irish, whose men's team came close to a medal in 1996 before winning silver in Rio in 2016, following that up with gold in Tokyo -- one of only 11 Olympic titles in the country's history.

Whereas some athletes in combat sports struggle to make their weight limits, Carpenter said that rowers expend so much energy that they sometimes have the opposite problem.

"Rowers would be needing to consume between six and eight thousand calories a day," she said. "So actually, sometimes eating is difficult, our athletes are training between 15 and 17 times a week."

The lightweight classes will be replaced by coastal rowing for the 2028 Olympics in Los Angeles, and Carpenter sees the changes as a chance to shift their priorities.

"We've massively focused on an open weight program," Carpenter said. "Because we know we have to go with the flow, you have to spend according to the change, so that's what we've done.

"Of course we're disappointed, but that's life isn't it? You just have to adapt and move on. We integrated with coastal rowing in 2018 and we've a large coastal rowing membership, so we're very excited about coastal rowing for L.A."

Coastal rowing uses wider hulls with a levelled off stern to allow water to flow out of the boat.