The Douglas region will feature heavily in this year's Ironman Cairns with the Great Barrier Reef Drive to be showcased to an international audience of millions.

The bike leg of the triathlon will take competitors on a two lap tour up the Captain Cook Highway to Port Douglas this year, before returning back to Cairns for a three lap course around Cairns' inner city. 

The stretch of highway - which was re-branded the Great Barrier Reef Drive as part of a campaign spear-headed by Tourism Port Douglas and Daintree - will be showcased heavily during the event.

The tourism body's CEO, Doug Ryan said the international sporting event was a great way to promote Port Douglas.

"We'll be working closely with event organisers and Tourism Events Queensland to ensure they can use the Great Barrier Reef Drive name as often as they can," he said.

"It's a  fabulous promotional outcome.

"The amount of exposure the drive gets at the event is phenomenal."

The Cairns Ironman brought an estimated nine million dollars into far north Queensland and Mr Ryan said the Douglas region got its fair share of the spoils last year.

He said a high volume of competitors chose to visit Port Douglas to recuperate after the gruelling race.

"You can always tell who they are," he said. "They wear their visors and walk funny down the main street after all that running."

More than 3200 competitors are expected to compete in this year's Ironman, with the 3.8-kilometre swim leg now starting in Palm Cove. 

"It is extremely exciting to bring this new course to the athletes and community," Ironman Asia-Pacific CEO Geoff Meyer said.

"The changes will also provide a more sustainable platform for the continued rapid growth of the event by reducing traffic management and tidal flow considerations in future years."

Several major sporting events in the Douglas region lead into Ironman Cairns, held on Sunday, June 8.

The Coral Coast 5150 triathlon and RRR Mountain Bike Challenge are held on June 1 in Port Douglas, along with the Great Barrier Reef Ocean Challenge which starts in Palm Cove and finishes at Four Mile Beach.