HOUSTON – It’s that time again!

The annual Chevron Houston Marathon is happening Sunday, and runners have been prepping for the big day.

Temperatures are expected to be in the 30s Sunday morning.

Despite facing the chilly temperatures and gusty winds on Friday, Memorial Park was packed with runners was are ready to tackle the 26.2 miles.

Mark Barr was amped and ready to go, despite fighting the wind and cold.

“Yeah, a little bit windy, hoping it’s not so windy on race day,” Barr said.

Perhaps, it’s the extra push he needs to achieving his yearly goal -- running in the Houston Marathon.

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And he’s doing it in his own way.

“I’m an above-the-knee amputee,” said Barr.

Barr lost his leg to bone cancer, when he was just 14 years old. Since then, he’s overcome the odds, challenging himself through sports.

“Sports is a huge part of my identity,” he said.

And this Sunday, it’s ready, set, go as he joins thousands of other runners to compete in the largest single day sporting event in the city.

Running 26.2 miles, he’ll be competing with other athletes with disabilities.

“So, we’ll be the first people on the race course, and it’ll be great, there will be space so we don’t trip on people,” he said.

But he wasn’t the only one getting in some last-minute training.

“I’ve run five marathons,” said Emily Thomas.

Thomas came out with her girlfriends all bundled up. The chilly temperatures were a nice change for her.

“Actually, I really like it, I prefer to run in the cold, it’s easier to shed layers then be hot the whole time,” she said.

It’s a sentiment a lot of runners are sharing.

As they each, prepare in their own way, marking their own path, for the big day.

Officials say up to 27,000 people are anticipated to run this year.