James Haskell has praised Eddie Jones' new fitness regime and believes England will reap the rewards of their hard work in the near future.
Haskell, who played for England against Wales and Uruguay in their dismal 2015 World Cup campaign, believes the new regime being implemented by Jones is 'more relevant' to their style of play.
"We did so much fitness work before the World Cup but it wasn't relevant because our games never went to those levels," Haskell said.
"It was very tough. But the ball-in-play time during the World Cup didn't bring the games to the intensity we wanted.
"That was probably the hardest fitness camp I have ever been involved with.
"What we are trying to do now is build a fitness that is relevant to the style we want to play and play at that intensity. That is the difference."
Jones was appointed as England coach in November 2015 and recently admitted the players do not make the grade for international rugby when it comes to their fitness.
However, since his arrival the Australian has brought in several new coaching staff, something which the England flanker also believes has benefited the players.
"The coaches have empowered the players, enabled them to improve and letting them be themselves," Haskell added. "They are letting us do stuff, be positive and have the senior players run things.
"England is not a place you want to be comfortable and relaxed. It is one thing being beaten by a better team but it is another thing not to show the right attitude. Eddie is driving a certain style of play."
And the intense fitness regime doesn't stop out on the practice field. Player performance is now heavily scrutinized with the latest technology to get the very best out of each player.
"We all wear the GPS vests, the heart-rate monitors and all that kind of stuff," Haskell revealed.
"We review training in terms of how quickly you get back into position and re-set, what your explosive metres are, how many high-speed metres you have.
"From the first session to where we are now, four weeks later, you can see that progression. Whenever I am playing, I am thinking about it now.
"A lot of people have fitness inside them but it is about being able to go to that place repeatedly and understand what it feels like to suffer.
"Some of the best players don't test particularly well but they are able to dig in during those intense moments when the play has been in play for four or five minutes. Everything about training is very intense. So I do feel in a better place."