Brantley Gilbert is well-known for his ardent support for U.S. troops and veterans, and he's putting his muscle where his mouth is to help bring awareness to a very serious veterans' cause.

Gilbert posted the video above to Facebook on Friday (Feb. 26) to let his fans know about the 22Kill campaign, in support of which he will do 22 pushups every day for 22 days. The campaign exists to call attention to the problems so many veterans have in re-adjusting to society after their service has ended, highlighting the fact that an average of 22 veterans take their own lives every day in the United States.

The "One Hell of an Amen" singer was called out by his good friend Justin Patterson, who served as an Army sniper until 2008, when his vehicle was destroyed by a roadside bomb. He earned four Bronze Stars and three Purple Hearts during his five years in Iraq and two years in Afghanistan. Patterson suffered a traumatic brain injury and suffered from PTSD so severe that he was barely able to leave his house for two years, but he eventually began to work with the Wounded Warrior Project.

He didn't know who Gilbert was when he met him at a motorcycle ride to support that cause, but he was so inspired by the star's support that he gave him his first Purple Heart in appreciation. Gilbert repaid him by giving him seats to the CMT Awards that year.

Gilbert is challenging his fans to support veterans by their own participation in 22Kill.

"This is how it works: You get called out, you get to call somebody else out," he says. "So BG Nation, I challenge you to do 22 pushups in 22 days. Send us your videos. I'll see y'all soon."

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