At 187 centimetres and 102 kilograms, Trent Morrow is not going to win any Olympic medals for marathon running, but the AIS was keen to get involved with the 39-year-old Sydneysider when he approached it for help to break a world record.

Morrow, who runs as "Marathon Man" raising funds for cancer charities, is attempting to run the most number of official marathons in a calendar year, starting with seven in a week, from January 1.

The world record stands at 114, but an American runner is already up to 140 marathons for this year, with that figure likely to go beyond 150 before the year ends.

Breaking that will be a logistical nightmare, but it is the physical and mental challenges that the AIS is keen to monitor as Morrow pushes himself to the limit.

The recovery physiologist at the AIS, Matt Driller, said he was excited about studying Morrow's journey. Their partnership started on Monday with baseline testing, which looked at blood readings, fat levels and oxygen use.

"He's crazy all right, but he's obviously a tough guy," Dr Driller said.

"He's done 78 marathons already, he's done some big desert marathons and backed up day to day, so he's shown he can do it - and I guess the other guys have shown it's possible.

"The main reason we're interested is that it's such an extreme case. He's obviously going to be digging himself into a big hole, overtraining, so if we can pick up little markers - whether it's in the blood or stuff from psychological questionnaires, or even physical tests … when he's about to dig himself into a hole, we can apply that to all the athletes that we work with."

Morrow received nutritional advice and tips to help him avoid injuries. His progress will be monitored with regular questionnaires about his mental state, as well as by measuring his body weight and resting heart rate.

Morrow, a pharmaceutical sales manager, started running six years ago when he realised he was 30 kilograms overweight. It only took him a short while to become hooked on setting himself and achieving a challenge.

His best time for a marathon distance of 42.2 kilometres is three hours, 56 minutes - not bad for someone who looks more suited to football - but Morrow is not too concerned about the clock.

"I don't think I'll do myself any favours if I go out there and try to set a new personal best every marathon.

"It's about conserving that energy and … making sure that I get through each event and I'm in a position to go rest and recover and turn up the next day at that start mark."

Organising the logistics has been a full-time job, with Morrow planning to travel to 20 countries to find enough races. "The strategy is all about looking for those events which tail into each other, and where I can realistically travel from one part of the country to the next.

"The majority of the year will be in the US, [and] that comes with its own challenges - Australians only have a tourist visa capacity of 90 days."

His other challenge will be his running outfit. Morrow plans on wearing the Marathon Man suit for as many races as possible, but it may not tick the boxes for comfort.

"He's going to be doing some pretty hot marathons, and it doesn't look like the most thermally effective suit,'' Dr Driller said.