If running a 5K footrace in the heat through Boston streets sounds challenging enough, imagine doing it on an empty stomach.

That’s what a group of Muslim volunteers will be doing this weekend during their third-annual Fasting 5K, a Cambridge-to-Roxbury trot right in the middle of the holy month of Ramadan. Proceeds combat childhood poverty.

During Ramadan, which runs this year from June 17 – July 17, Muslims forego food and liquids from dawn to dusk. While the observance makes the run a difficult task, it also aligns with the teachings of Islam, said Zahid Siddiqui, race co-founder.

“Ramadan is all about sacrificing, treating others like you would like to be treated and being good to your neighbor,” Siddiqui said. “During this time I think most Muslims always try to up their game.”

Siddiqui and other friends were hanging out in Boston in 2013 when they dreamed up the idea for the 5k, he said. It has since spread to six locations worldwide – Detroit, Austin and Washington, D.C., as well as Doha, Qatar and Huntington Beach in Southern California. About 200 runners are expected to take part this year.

In each city, races are timed to end near sundown so runners can drink Gatorade and eat granola bars – their first bits of sustenance since about 3:30 a.m., Siddiqui said.

Typically, he said, Muslims try to avoid exerting themselves during fasts, as even mowing the lawn can be a struggle with nothing to eat or drink.

“We always send out an email to the participants to make sure they get their fluids in the morning and make sure they’re eating a few bananas and pasta to keep them energized through the race,” he said. “We’re really stressing to run at your own pace.”

The relatively small network of runners has so far raised $45,000 in donations, each year focusing on children in need. F5K funds have stocked three computer labs with equipment for low-income youth, and last year helped purchase backpacks stuffed with school supplies for Boston students, in a collaboration with the Islamic Circle of North America Relief’s Boston outpost.

The fundraiser is a boost for ICNA Relief, said Malika Rushda, a leader in the city’s branch. It also comes, she said, during the Muslim equivalent of Christians’ charity efforts around the Holidays.

“There is a spirit similar to the Christmas season of giving, and I think these young people, they’re making that sacrifice which I think is incredible. I couldn’t imagine fasting and running,” Rushdan said. “It takes tremendous strength and endurance. They’re really raising awareness and a tenant of our faith is to care for humanity.”

Where: Runners will travel from the Islamic Society of Boston in Cambridge to the Islamic Society of Boston Cultural Center in Roxbury.

When: Saturday, July 11, 7 p.m. – 8:30 p.m.

How to help: Registration for the race is closed, but you can still head to Fasting5K.org to donate.