(Photo Credit: Sebastian Kim/GQ)

After playing two of the most influential Americans, Jackie Robinson and James Brown, actor Chadwick Boseman is a long way from the days when he first started acting.

"I think the most stressful time of my life was when I was in New York and I didn't have money to pay my rent," the 37-year-old actor told the October issue of GQ. "I was going to the mailbox every day waiting for the check to come. When you don't have money, when you've got, like, a jar full of change and each day it's, 'OK, I've got enough to get on the train' and 'Maybe that check's gonna come today…' There's nothing more stressful than your stomach growling."

Added Boseman: "Interestingly enough, some of my best writing came when I was poor and hungry, living off water and oatmeal, mind clear."

How 'Get on Up' Star Chadwick Boseman Transformed Into James Brown

After spending his 20s and early 30s pursuing writing and directing, Boseman got his big break as an actor at 35, when he was cast as Robinson in "42." Two years later, he was playing the Godfather of Soul in "Get on Up."

Both roles were extremely physical. "I did the splits ninety-six times one day on 'Get on Up,'" Boseman revealed.

His portrayal as Brown is being touted as Oscar-worthy, but Boseman isn't exactly ready to rest on his laurels.

"I'm not kicking back enjoying the spoils," he told the magazine, "because it's like I don't think I've done my best work yet, you know what I'm saying? It ain't no time to rest right now."