Malcolm Johnson prepares to run the Boston Marathon

It's an ultimate test of strength and resilience.

"I think I'm doing it for a purpose," NBC10 Boston reporter Malcolm Johnson said. "It's something bigger than myself. It's a chance to give back."

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That's part of the reason why Johnson chose Boston as his first ever marathon.

"This is going to go to help kids who need it the most. Kids who have life altering diseases, medical expenses that are pretty lofty," he said.

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Johnson is running for Boston Children's Hospital. The money he's raising will help support kids and their families who are undergoing medical care.

Our own Matt Prichard and Malcolm Johnson sat down to discuss how they've been getting ready to run in the Boston Marathon and the charities they're doing it for.

The training hasn't always been easy. He's done practice runs in the cold and sometimes snowy weather.

"Your mind might say no, but you just go through it and you do it day after day after day -- eventually it becomes autopilot," Johnson said.

But he said part of the process is learning about yourself.

"You get to see what kind of athlete you are," Johnson said. "When you're at mile 15, 16 and 17 -- farther than my threshold has even been -- I start to test the waters and boundaries of what I'm physically able to do."

And he hopes to take that mindset into a successful Marathon Monday.

"Do things that scare you a little bit and you'll probably get a version of yourself that you didn't know was there," Johnson said.