Graham Rowntree has urged England's players to put more focus on fitness and agility during their pre-World Cup training camp.
Having run in 18 tries in five games during this year's Six Nations, the Red Rose are expected to once more deploy an attack-focused game during the showpiece tournament on home soil.
In order to do so, England's forwards coach is determined to get the best out of each member of the squad by prioritising pace and skill over bulk and brawn.
"Is the game changing? You look at how it's changing around the world, how often forwards have the ball in hand," he is quoted as saying by the Daily Mail. "The times a forward and a back with exchange passes, the times passes go to second-row forwards.
"You admire great defence, but you can't keep running into brick walls and hope to succeed. So there's more attacking rugby going on. We certainly don't want our boys to get any bigger. I think we have plateaued there. We are asking for a greater output from all of them.
"What is crucial is there cannot be any wastage. You cannot be carrying additional weight. But I don't want my guys up front getting much bigger than they are."
England will head to Denver next week for the next stage of their fitness drive ahead of their World Cup opener on September 18.