Organisers of New Zealand's biggest marathon are calling on entrants to dig deep this year - into their pockets as well as in physical endurance.
Figures released by sponsor ASB show just 10 per cent of the 12,000 entrants in the Auckland Marathon last year raised money for charity.
Of the estimated 36,000 runners who took part in the London Marathon, 80 per cent ran for charity.
Realbuzz Group's Dominic Boekweit, who manages the charitable side of the marathon, said the English race was one of the biggest fundraising events in the world.
"Scenes over there are huge. Even some New Zealand charities go over there to take part."
Auckland's size meant the local race was unlikely to reach the scale of London's, but he hoped to increase the percentage of the field running for a good cause.
Money raised in the Auckland field has grown since the programme started in 2012.
Then, a total of $150,000 was raised; by 2014 that had risen to $1.5 million.
But last year it slumped to $1m, which Boekweit said was because of the clash between the marathon and the Rugby World Cup final.
This year, runners who would like to do their bit for charity can choose from the "Gold Runner" or the "Own Place Runner" programmes.
Runners in the gold category commit to fundraising a minimum of $1500-$2000 for their chosen charity.
Runners in the latter programme can support their charity without a minimum target.
This year there are close to 30 charities to choose from, including the Heart Foundation, the Mental Health Foundation, Child Cancer Foundation, Hospices of Auckland, the Cancer Society and the Starship Foundation.
Starship plans to use any money raised to fund its squad of Clown Doctors.
Much like Patch Adams, the doctor depicted by actor Robin Williams in a film of the same name, the group of clowns helps bring humour into hospital wards.
Starship said the clowns brought much-needed laughter to young patients, like Whanganui boy Duane Izett.
Born with arthrogryposis, a condition that affects his limb joint mobility, Duane has had to go to hospital for check-ups and surgeries every six months since he was 4 months old.
Mum Nadia Lacy said a clown doctor helped put a smile on his face after his latest surgery.
"The Clown Doctors came into our room and cracked a few jokes; it was the first time Duane had smiled since he'd been out of the operating theatre."
She said Duane often looked forward to seeing one of the clowns. They helped "lighten the mood and are great for adding a playful atmosphere on the wards".
Starship Foundation's community fundraising executive Krissy Garnham said every person running for the charity was a "superhero" for thousands of young patients.
"You really do not need to be a super athlete to make a difference. You just need to be a superhero fundraiser."
• For more information on how to run for charity go to aucklandmarathon.co.nz/run-charity