The Kathmandu Adventure Series advertises itself as a race for "weekend warriors looking for some physical, out of the ordinary fun and a true sense of accomplishment".
Its appeal to people with "any fitness level" is what enticed two old Winmalee High students to have a go in the race, to be held this weekend.
Carrick O'Connell and his mate Ben Rayner, 30-year-olds from Glenbrook and Winmalee respectively, call themselves the "Broke Dads" team, which they say accurately describes their current life circumstances.
It will be their first attempt at adventure racing.
Mr O'Connell said he started training last November, both to get fit and to lose weight. Some 10 kilos lighter later, he is ready to compete.
The race, on August 2-3, will be held somewhere in the Lower Blue Mountains but the exact course will not be revealed until the morning of the race. This evens up the contest by ensuring no-one can get an unfair advantage by practising on the course beforehand.
Teams of two will alternatively run, mountain bike and kayak, completing the course as quickly as possible, which is typically anywhere between two and six hours.
O'Connell and Rayner think their mountain bike leg might be their strongest, but they have also been putting a lot of time into running.
"I can run a consistent speed for a long period of time while he's a sprinter," Mr O'Connell said. So the pair have been training together twice a week, encouraging one to improve his speed and the other his endurance.
The kayak leg may be more problematic. Mr O'Connell said he has been in a kayak before, but not for some time and not competitively.
"So I suppose for the race I just need to do the same things but a lot faster," he said.
The adventure series touts itself as "the perfect starting point for those looking to experience the adrenalin rush and sense of achievement that the sport of adventure racing has to offer".
Entry is $105 per team, which includes race maps, an end of race meal, kayaks, paddles and floatation devices plus a chance to win part of a prize pool of $20,000.
Details, email firstname.lastname@example.org.