A reduction in the number of interchanges means NRL forwards have had to shed kilos in a hurry, writes Brad Walter.

MARK RIDDELL hasn't had a drink since New Year's Eve, Ashton Sims has given up pizza and Chinese takeaways and several other NRL forwards are also shedding weight in preparation for the reduction in the number of interchanges this season.

With each team able to make only 10 replacements during a game instead of 12, players such as Riddell and Sims are expected to endure longer stints on the field and the former St George Illawarra teammates have slimmed dramatically over the summer.

Gone are the double chin and spare tyre that earned Riddell, Parramatta's first-choice hooker, the nickname "Piggy", while Sims is the fittest he has ever been after making the move to Brisbane at the end of last season.

"It's been good for me, the Broncos are really big on skin-fold testing and getting your body fat down and I think I'm benefiting from it," said Sims, who estimates he has lost about five kilograms.

"The main thing for me has just been eating the right things. I used to be all right during the week but then I'd go out and wreck it on the weekends by getting a pizza on Friday night and then Chinese on Saturday night. I'd have an entree, a main - the lot."

Riddell, who once famously told Dragons coaching director Laurie Daley and a dietitian that he drank about 40 schooners a week and then when they thanked him for his honesty added that he hadn't mentioned the bourbon and cokes, has dropped 8kg after abstaining from alcohol for the longest period of his adult life.

Still harbouring the old-fashioned belief that a player's time off at the end of the season is exactly that and should therefore not involve fitness work or the restrictions on eating and drinking they have to endure while playing, Riddell usually has to start from scratch when he returns to training and this time wasn't much different.

"I certainly wouldn't say he was in great shape," Eels coach Michael Hagan said. "But when the changes to the interchange rule were first mooted we spoke about the need for Piggy to spend more time on the field and he's certainly taken that on board and made some changes to what he was doing. I think he'd had any number of people make suggestions to him in the past about what he needed to do but at the end of the day it's up to him."

Under the new rule, Hagan estimated that props would still be rotated as often but hookers and back-rowers would now have to play for significantly longer periods.

Sims, who will tonight make his Broncos debut in a trial at Rockhampton against North Queensland, said he was expecting to play 55 to 60 minutes per match in the front row this season.

"It's only two less interchanges but it is going to make a massive difference because most coaches like to have two up their sleeve near the end of a game so every club will want their forwards to be able to go harder for longer," Sims said.

Offered a release by Dragons coach Nathan Brown last season, Sims said the move was a chance for him to re-ignite what had been a promising career and he has set his sights on playing representative football.

"I feel like Wayne Bennett has made a really big impact on me already, just with my attitude towards football," he said. "It was only a couple of days after I was told I could look for another club that Wayne rang me so I flew up here to have a look around and that was really how it all came about. I nearly fell off the lounge when I realised it was him.

"At first I thought someone was mucking around with me and I said, 'Who is this really?' but everyone knows his voice, it's sort of deep, so when he said, 'No, it is Wayne Bennett' I thought someone's done a really good impersonation or it really is him. You only hear about him down in Sydney and Wollongong so for him to ring me was really good. It was very shocking when he told us he was leaving at the end of the season but I'm going to pick his brain as much as I can before then."