By MIKE PETRUCCI

My backpack is weighted down with bricks. My mouth tastes like saltwater. I am on my hands and knees, soaking wet and crawling in sand. It’s around 2 a.m. along an empty stretch of the Atlantic Ocean, one hour into the GORUCK Challenge. We’re in Rehoboth Beach, Delaware, for the boot-camp event, a 10+ hour team feat led by a former Green Beret.

Earlier in the night I had signed something called a “Death Waiver,” a mandatory sheet of legalese put together by the organizer. Now, I am following the glow of a headlamp, my hands in sand, working to keep up with a group of motivated, crazed men.

GORUCK Events LLC holds “challenges” like this all over the country. They started as participatory “product tests for GORUCK gear,” which is the namesake line of packs and military-inspired softgoods the company sells. But the GORUCK Challenge, which I completed on May 7 this year, has evolved into a growing series in its own right. This year, the events are in most every major city in the country.

My “class,” a group of 15 men from around the East Coast, began our GORUCK experience at 1 a.m. We shouldered the company’s backpacks — a mandatory piece of gear for everyone involved — and tromped off into the night. What lay ahead, I did not know at the time, would change me for life.

It took us 13 hours to finish our challenge. Along the way, we jumped into dark ocean waters, ran, crawled, climbed over obstacles and rocks, did push-ups with our feet raised, hoisted up huge logs, and carried our teammates on our backs. We moaned and worked to stay motivated. We got weird looks from townspeople in Rehoboth Beach, a sleepy community “invaded” for one night by the GORUCK group.

Near the end, there were 14 of us left standing — one guy had dropped out, and the rest of us were squinting to see the finish line. I was pushed like never before and discovered what I am made of, mental and physical both. I got emotional and teary at the end of the Challenge, I will admit. What can I say, this experience triggered something in me.

The military boot camp event was something of a revival for me — I feel no longer bound to a world where things are impossible! I’d never done anything like it before. But now, I can’t wait to do it again!

—Mike Petrucci is based in Washington D.C. He is currently training for the GORUCK Ascent, a 100-hour event in Colorado. He is hoping to raise $1,000 for the Green Beret Foundation, a charity affiliated with the GORUCK events.