"I saw the email, then I looked at how long it was and I did not read it," former World No.1 Dustin Johnson said.

The American ranked fourth for driving distance on the PGA Tour last season with an average of 312 yards.

On Tuesday, the United States Golf Association (USGA) and the Royal & Ancient (R&A) jointly released the Distance Insights Report.

The report claimed golf has a distance problem and that ever-increasing length was "detrimental to the game".

"To be honest ... I looked at it and it was like 18 pages or something. I didn't even try to read it," 20-time US Tour winner Johnson said before this week's Pebble Beach Pro-Am.

The report said that since 2013, the average driving distance on the PGA Tour and European Tour have increased at a rate of about one yard (0.9 metres) per year, now averaging 294 yards.

β€œTo be honest ... I looked at it and it was like 18 pages or something. I didn't even try to read it.” – Dustin Johnson

Top women have shown a similar rate of increase, now averaging more than 250 yards on the LPGA Tour.

The report promised an industry-wide review and with a possible "bifurcation" of the rules, which could lead to elite and recreational players using clubs and balls manufactured to different regulations.

The governing bodies said they planned to conduct further research and get feedback from manufacturers before deciding upon any changes to equipment regulations.

But Johnson said the biggest hitters, including himself, World No.1 Brooks Koepka and Rory McIlroy, would still smash it past their peers.

"I don't see that changing," the 2016 US Open winner said.

"And to be honest, it's not like the scores are lower than they used to be or that they're any different."

Five time-major winner Phil Mickelson agreed with Johnson while taking aim at the USGA and R&A, questioning their experience in professional golf.

"I struggle with some of our governing bodies," defending Pebble Beach Pro-Am champion Mickelson said.

"I struggle with it because we're the only professional sport in the world that is governed by a group of amateurs (golfers) and that leads to some questionable directions that we go down."

- Evin Priest, Australian Associated Press