England rugby players are more likely to get injured under coach Eddie Jones.
Players were twice as likely to be injured when training with England last season than the average since 2002 and those injuries kept them out of the game five times longer.
The RFU injury report follows a year in which several players were sent back to their clubs unable to play after serious injuries sustained on England duty, leading to criticism of coach Eddie Jones' methods.
Details on all injuries sustained by English professional players in club and international matches and training have been recorded and analysed since 2002 in the Professional Rugby Injury Surveillance Project (PRISP) and its report for 2017-18.
The document was produced in conjunction with Premiership Rugby and the players' association.
Although the 2017-18 figures concerning England came with the caveat that the relatively small sample meant the results could be skewed, they showed the incidence of injuries during on-pitch training was more than double the average.
The mean length of absence was 579 days per 1000 hours, compared to the overall mean of 96 days per 1000 hours. The injuries appear to be becoming more severe, or perhaps treated more sympathetically, as those suffering injuries in England matches were absent for an average of 30 days compared to 19 days during the overall study period.
Last May, Bath owner Bruce Craig said the level of injuries sustained on England training camps was "totally unacceptable" after young prop Ben Obano suffered knee ligament damage expected to keep him out of the game for a year.
He was one of several players who were sent back injured to their clubs and the fifth from Bath in recent seasons. Wasps flanker Sam Jones was forced to retire last year after suffering a catastrophic broken leg during a judo session with England in 2016.
England coach Eddie Jones, who took over after the 2015 World Cup, hardly endeared himself to club owners when he responded to Craig's criticism by saying they "had no right" to tell him how to prepare his team.
The latest figures are not likely to placate them either but Nigel Melville, the RFU's interim CEO, said action is being taken after discussions with the Professional Game Board.
"Obviously international rugby is played at a greater intensity so training is at a greater intensity so we are trying to manage that transition," he told journalists.
"I think that's starting to show some positive signs. It's early days but we did recognise a problem and working with the clubs' conditioners and coaches, we think has improved the situation."
Melville said it was not just a question of Jones's training methods but also looking at pre-training preparation.
The report showed that the overall number of injuries in all competitions was slightly higher than the yearly average but that there had been a steep rise in the number of more severe injuries leading to lengthy absences.
For the seventh consecutive season, the most commonly reported match injury in the Premiership was concussion, accounting for 20 percent of all injuries, though there was a slight fall in incidents from the previous year.
The report said it was too early to draw conclusions from the lowering of the tackle height experiment being trialled in the Championship Cup in a bid to cut down the number of concussions but that there was still a concern that high tackles were not being policed firmly enough by officials.
"If there is a desire to change player behaviour to reduce the risk of concussion, we believe that the threshold for receiving a card for a high tackle is currently too high," the report said.
RFU medical services director Simon Kemp, who has been at the forefront of the battle to recognise and minimise concussion risk, said varying interpretations of a high tackle were not helping.
"Around the world you are three times more likely to see a yellow card given for a deliberate knock on than a high tackle," he said.
The PRISP report identified four priorities for continued injury reduction. These were looking at potential law changes, the application of laws, a better understanding of injury risk in training and more research on the risk posed by artificial pitches.
The report comes after news that a fourth French player has died within eight months from injuries sustained in a match. Nathan Soyeux, a 23-year-old student, passed away in Dijon on Monday after suffering injuries in a game in November.
A spokesman for World Rugby said the governing body particularly welcomed the reduction in concussions, saying in a statement: "We will continue to collaborate with all unions and international players on evidence-based solutions to mitigate injury risk as demonstrated via the wide-ranging programmes being implemented in 2019."