July 10 (UPI) -- A serial Guinness World Record breaker completed a marathon in under 6 hours while under the weight of a staggering 125 T-shirts.

David Rush, who holds the most concurrent Guinness World Records titles, said he decided to take on the title for the most t-shirts worn during a marathon after setting the half-marathon version of the record with 137 T-shirts at the 2025 Famous Idaho Potato Half Marathon.

"In the heat of that victory, I felt invincible. I thought, 'If I can do this for 13 miles, I can easily double it.' That was a classic case of pride coming before a very painful fall," Rush wrote online.

Rush spent months training for the attempt by running with heavy weights and thick layers of clothing.

He ran the 2026 YMCA Famous Idaho Potato Marathon on May 16 while wearing 125 shirts.

Rush said he had one major health scare during the attempt when he started to overheat and ran out of ice. He ended up stopping at a golf course along the marathon route.

"Patrick, one of my support runners, sprinted into the pro shop to beg for emergency ice. That ice was the only reason I didn't end up in the hospital," he said.

Rush ended up finishing the race with a time of 5 hours, 54 minutes, and 50 seconds -- leaving him with only 5 minutes to spare before the Guinness World Records cut-off time of 6 hours.

"The process of peeling 125 shirts off my body felt like an exorcism," he said. "My skin was red, raw and crisscrossed with bloody, five-inch-long chafing marks where the bottom of the shirts had ground against my skin for six hours. My back was indented from the constant pressure of 43 pounds of clothing."

Guinness World Records has now confirmed that Rush officially broke the previous record of 100 T-shirts.