Worcester Warriors head coach Richard Hill says they will be among the fittest teams in the Premiership.
He admits some of the new boys have found it hard going at Sixways and says they will have to step up a level for the return to the top flight.
He told BBC Hereford and Worcester: "They are in a full-time professional programme and it is tough.
"This programme has to be one of the hardest in the Premiership. The way our coaches are working them is gruelling."
He added: "Some of them are quite grateful of the weekend, they collapse and don't do much but lie in bed."
Hill says his new players have fitted in well, but it had been even harder for some for them to adjust to training at Sixways.
"The 11 new players have come in and have added something," he said.
"They all have a good work ethic, one or two are not used to the intensity of this sort of training
"Ben Gulliver has joined us from the (Cornish) Pirates and he says we certainly train harder than the Pirates have.
"What I am delighted about is, touch wood, after four weeks of high intensity we have only picked up one small injury."