Australian rower James Tomkins has experienced many different conditions in his previous five Olympics and believes the Beijing heat and humidity will be the toughest he has faced.

The three-times Olympic champion, who is tipped to carry the Australian flag at the Beijing opening ceremony today, said he also planned to retire after the Games but would like to return to rowing in some way after a break.

"The course is good, it's just the heat and humidity are pretty poor, probably the toughest conditions that I've experienced," the 42-year-old told Reuters in an interview.

Tomkins competed in his first Olympic Games in Seoul at the age of 23, finishing fifth in the eight, before winning gold in the "Oarsome Foursome" in 1992 and 1996.

His Olympic progress was then disrupted as his pairs partner and friend Drew Ginn injured his back in the build-up to their home Games in Sydney, leaving Tomkins to win bronze with a new partner. But the two were reunited to win in Athens with a display of near-perfect technique.

"A lot has changed," Tomkins said of his more than 20 years at the top of the sport, noting the development of the Chinese.

"They've had a massive push, obviously for the Games, and the standard and the depth of their team is phenomenal."

The Chinese squad, which has never before won an Olympic rowing gold medal, is a genuine challenger in several events in Beijing. But Tomkins said the home advantage can work both ways.

"We had a big push going into the Sydney Olympics and it seems to have carried on afterwards," he said of the Australian rowing team which will be the only country to contest all 14 events. "It probably does (increase the nerves) a little bit but it's also a massive boost."

Rowing opens tomorrow with Tomkins' eight racing a day later.