Farmer, fireman, challenger extraordinaire and underwear model - Norway's double Olympic sculling champion Olaf Tufte does not fit the bill of your average professional sportsman.

The 36-year-old complements his rowing training by dragging trees and sacks of grain across his farm and will enter his fifth Olympic Games in London without a win at any major event since success in Beijing in 2008.

Not that form should worry Tufte. His victory in China followed a similar pattern in the preceding years with the tall Norwegian now renowned for his ability to ramp up the pace when it matters.

"I've been struggling with health issues and energy levels," he told Reuters in an interview. "My body has not been at its best so I'm working hard and I haven't given up. A lot of people are counting on me to get back in form."

Some of those who will not be counting on Tufte however are the group of close friends he will line up against on Dorney Lake on July 28, including the popular favorite Mahe Drysdale from New Zealand, the Czech Republic's Ondrej Synek and Alan Campbell of Britain.

With years of racing against each other, the leading single scullers often talk about a respect and support for their rivals, visiting their homes and training together for what is regarded as one of the toughest events in the rowing regatta.

For Tufte his success has come from a variety of training methods including cross-country skiing, dragging trees, chopping wood with an axe and running with sacks of grain on his back, which can exacerbate his asthma.

His prowess in this field comes to the fore every year when he hosts the Tufte Farmers' Challenge, inviting top athletes from across Norway to take him on in competition sawing, chopping wood, pulling cars and tyre flipping.

The continued success and quirky approach - pictures on his website show him wearing a winter hat and modeling "Olaf Tufte" underpants - has helped Tufte to lift his own profile and the profile of the sport within Norway, attracting more people to take part.

Following his victory over Synek and the now five-times world rowing champion Drysdale in Beijing, Tufte returned to form a "Team Tufte" to help train younger athletes including two who are favorites for a medal in London in the double scull.

Nils Jakob Hoff and Kjetil Borch won the final world cup race before London on June 17, having led from the front to beat many of the crews who are likely to make up the Olympic final.

"Rowing is not a big sport in Norway but at every Olympics the heat gets turned up because of the medals," Tufte said. "I started a team after Beijing called Team Tufte and the young boys who won in the double are in the middle of a media storm.

"For me, the level will be higher in London than Beijing and there...will be a wider field. I think we're up to 10 or 12 people who could make the final (six places), and that obviously makes it a lot tougher."

Few of those will have as much experience as Tufte. Having finished eighth in a four in 1996 in Atlanta, the father of two who stands at 1.93 meters and weighs 95 kgs won silver in Sydney and world championship gold in 2001 and 2003.

With this in mind, his rivals have warned that you can never count Tufte out. In Beijing he rowed through the field in the sprint for the finish to leave the favorites standing.

"I would be glad to be as optimistic as the people around me are," Tufte said. "My body is not on top at the moment but a little more energy and improved technique and I'll be getting the right speed. It's about the little things now.

"I'm going to be even more focused and even more serious. I haven't given up, I'll be there."

(Editing by Clare Fallon)