For the last two years, Hobart's former Olympic rower has not only led the gruelling event but set a course record for the bike leg only to be run down in the marathon.

Last year he eventually finished ninth in 8:10:32 - the best result by a Tasmanian and third fastest by an Australian.

And on Sunday, just three weeks after winning Ironman Italy, Wurf, 36, shaved another chunk off that record as he came fifth in 8:06:41.

Tackling a 3.8-kilometre swim, 180km ride and 42.2km run, Wurf recorded the second fastest bike leg of 4:15:05 and began the run in third place, 3:08 off the lead.

A marathon later, he finished 15:29 behind German Jan Frodeno (7:51:13), who added to his two previous wins in 2015 and '16.

Wurf, who was also a WorldTour pro cyclist, has spent the last two weeks in Kona preparing for the race.

Launceston's Joe Gambles finished 36^th in his fifth ironman world title as a professional triathlete.

"Although I feel that I have never put together my best performance here, I have never become disheartened and instead I have looked at each race as a learning experience," he said on Facebook this week.

The 37-year-old, who came second second at the 2011 ITU Long Distance Triathlon World Championships and third at the Ironman 70.3 World Championship the following year, thanked family and friends for supporting his racing.

Three Tasmanians are set to join the Australian women's rowing program.

Huon clubmates Sarah Hawe and Georgia Nesbitt will join Tamar's Ciona Wilson at the women's National Training Centre in Penrith after the latest intake announced by Rowing Australia this week.

All three attended the recent world championships in Austria where Hawe, 32, was a member of the gold medal-winning women's four, Nesbitt, 27, stroked the lightweight women's double to ninth and Wilson, 27, was a reserve for the women's eighth which finished second.