The American couple murdered in an ISIS-claimed car attack in Tajikistan quit their office jobs last year and were in the midst of pursuing their lifelong dream of cycling around the world when they were killed.

Jay Austin and Lauren Geoghegan, both 29 and living in Washington, DC, chronicled their adventures on a blog called “Simply Cycling” where they wrote that they’d decided to take on the globe on two wheels, “because life is short and the world is big and we want to make the most of our youth and good health before they’re gone.”

Before embarking on the trip, New York-born Austin worked in the Department of Housing and Urban Development for seven years, his mother, Jeanne Santovasco, told The Washington Post.

“He was just a gentle soul who cared about the world and not leaving any footprint and leaving it a better place,” she said in an interview on Tuesday.

In 2012, Austin was the subject of a video for Reason.com about the 145-square-foot tiny house he built and lived in.

His girlfriend, Geoghegan, grew up in California and graduated from Georgetown in 2010 and worked in the school’s admissions office until taking off on her whirlwind trip with Austin.

Her parents, Robert and Elvira Geoghegan, said in a statement that her trip “was typical of her enthusiastic embrace of life’s opportunities, her openness to new people and places and her quest for a better understanding of the world.”

On their blog, they described the kindness and generosity of people they encountered in Africa, Europe and Asia — but also some tough days.

“Badness exists, sure, but even that’s quite rare. By and large, humans are kind. Self-interested sometimes, myopic sometimes, but kind. Generous and wonderful and kind. No greater revelation has come from our journey than this,” Austin wrote.

The slain couple had planned to continue traveling for another year “or two or three,” they’d written. “But only if we’re enjoying it.”

“For them to be in this one place where they decided to kill people is unfathomable to us,” said Austin’s mother.

About a week ago the pair had posted on Instagram about Tajikistan being a tough place to cycle.

“It’s cold and windy and mountainous,” Austin wrote, adding that Geoghegan had caught a nasty stomach bug and was having difficulty biking

Then on Sunday, assailants rammed a car into cyclists in the countryside south of the capital, Dushanbe, before pouncing on them with knives.

Rene Wokke from the Netherlands and Markus Hummel from Switzerland were also killed.

The Islamic State claimed responsibility for the attack, which would make it the terror group’s first in former Soviet Central Asia.

But authorities in Tajikistan didn’t accept the claim, blaming the attack on a banned political party instead.

A US State Department spokesman condemned the “senseless attack on civilian cyclists,” adding that Washington was ready to assist with an investigation.

The US Embassy in Dushanbe are welcoming visitors to sign a condolence book for the couple, it wrote on Facebook.

“We’ll be forever be inspired by their kindness and open mindedness and their happiness,” one cyclist wrote in the book.