When American Bo Van Pelt first arrived on the professional scene in 1999, the gym was a relatively foreign concept to most golfers.

Not anymore.

Van Pelt will be aiming to defend his Perth International title this week when he contests the $2million event at Lake Karrinyup Country Club.

But he faces stiff competition in the form of world No.21 Dustin Johnson, who is part of the new-age golfing prototype taking over the game.

Standing at 193cm, Johnson is an athletic marvel who has established a reputation as being one of the biggest drivers.

He can also dunk a basketball in bare feet and perform a standing long jump that would put him in the top seven percentile of NBA players.

Van Pelt says golfers need to be both extremely fit and skillful if they are to succeed at the elite level.

And having an athletic predisposition definitely helps.

“Twenty years ago, the average height was probably 5’8 or 5’9 (172cm or 175cm),” Van Pelt said.

“Now you see guys 6’4 (193cm) that were good athletes in other sports. You’re just going to see more and more of that.

“When I first got on tour in ’99, there were not that many guys in the gym working out.

“It wasn’t hard to find space in there.

“Now you go in there sometimes and it’s too busy. You can’t even find a spot to go in there and work out.

“The younger kids coming up, that’s just part of their routine.

“They start getting these customised workouts when they are in junior high.

“Then they go to college and then by the time they come on tour, it’s kind of part of their DNA.”

Van Pelt was forced to withdraw from August’s USA PGA Championship due to a hip injury.

The 38-year-old has used the past six weeks to recover, and says he feels good heading into the Perth International, which tees off on Thursday.

The world No.44 said the wear-and-tear injury proved how fit you needed to be to play professional golf week in, week out.

“We are playing a lot and walking five to seven miles a day and it just kind of caught up with me at the PGA,” he said.

“It was kind of lingering all summer.

“It had kind of started in my foot, my achilles tendon and went up to my hip.

“Fortunately I didn’t have any tears.”

Other notable names to contest this year’s Perth International include England’s Paul Casey, South Africa’s Branden Grace and Australian Brett Rumford.