England delivered one of their most dynamic performances for years to beat Australia in Sydney in June and, responding to fundamental changes in the refereeing of the breakdown, the first two weeks of Premiership games have displayed a high-paced approach unrecognisable for the much of the turgid fare on offer last season.
"Last summer I thought that we could improve our fitness in certain areas. It's definitely better now and it needs to be," Johnson said.
"The guys came in recently and were tested and the results were the best since I've been here. Some of them had world-class statistics a year ago but others who weren't quite there have improved.
"What we've seen in the first two weeks of the Premiership has been great - the continuity in the games, the ability to keep the ball and run it, and the speed at the breakdown."
At Twickenham Johnson and members of the RFU's backroom staff were displaying the GPS monitors that they are using to monitor every aspect of players' fitness and mobility.
Players at eight of the 12 Premiership clubs are this season wearing mobile-phone sized GPS monitors, housed between their shoulders in specially-designed vests, in matches. The International Rugby Board gave special dispensation for the experiment, overruling their own law outlawing hard objects.
The RFU has been using the devices in training and Johnson says the information they provide is a huge help.
"The numbers we get back mean we can see exactly whether a player is at his peak in terms of speed, heart-rate, recovery, it evens measures jumps and starts and means we can monitor performance but also exactly control what sort of training volume and intensity each players has," Johnson said.
Already the information gleaned has led to a rethink of some long-established routines as what were previously considered to be light run-outs on the day before a test, and even pre-match warm-ups, were discovered to be more physically taxing than the conditioning coaches wanted.
Johnson, however, knows that technology goes only so far.
"Fitness-wise we are up there now but the key thing is what the score is when we play teams like New Zealand," he said.
The All Blacks, who have beaten England eight times in a row and fresh from a Tri-Nations clean sweep, are the first visitors in the November internationals when England also take on Samoa, Australia and South Africa.
"In a way it's good that we've got New Zealand first," Johnson said. "I'm not fazed by what I've seen in the Tri-Nations but what I've told the players is that we have to get back to test match intensity from the start.
"We talked about it before the summer tour to Australia and New Zealand but the players have to experience it for themselves.
"Even in the midweek games the players were saying afterwards that it was the fastest pace they had experienced.
"In the first test against Australia we started slowly but we were much quicker out of the blocks in the second.
"After Sydney a lot of guys now understand what it takes to win a test with an 80-minute performance."