A pair of Singaporean dog groomers working in B.C.'s Lower Mainland are putting their military training to use as they prepare to conquer a grueling ultramarathon in honour of old and unwanted pets.

Serene Lee and Nicholas Khoo, the owners of Suds 'n' Scissors dog grooming in Coquitlam, have been feverishly training for months to compete in the Squamish 50, which crosses some of the toughest terrain in the Sea-to-Sky region.

The 80.5-kilometre race has 3,300 metres of climbing and descending, and leaves even the most experienced runner weak in the knees.

Even though Khoo and Lee have participated in several marathons, they are not veterans in the backcountry. They did their first trail run only a few months ago, and are training six days a week to prepare for the challenge.

"It's brutal. I'm not going to sugarcoat anything," Khoo, 47, says of the prep work.

He and his partner alternate between long runs of up to 40 kilometres, hills and stair work – using a friend's high-rise as a makeshift training facility.

The animal lovers aren't just running for themselves – they're raising money and awareness for S.A.I.N.T.S., an end-of-life sanctuary for old, sick and unwanted dogs in Mission, B.C.

The volunteer-run farm takes in animals that no one else wants, and it's a cause that that hits close to home for the couple, who own a rescue Cocker Spaniel.

"It just touches my heart that these animals are not really adoptable because everyone wants a puppy," Lee said.

They've set up a GoFundMe page and are hoping to raise at least $3,000 for the sanctuary, so that every step they take is a journey that also helps animals in need.

You can follow their journey on their Facebook page, the SOLE Mates Miles for SAINTS

"With their military training and the training they've been doing I think they'll do pretty well," said race co-director Geoff Langford.

"Plus it's a good cause so I want to see them finish for sure."

With a report from CTV Vancouver’s Scott Hurst