After being diagnosed and treated for osteoporosis, spondyloarthritis and hypogonadism Welch tells PEOPLE he felt that he had been given a second chance at life
Every morning, Missouri elementary school teacher Kim Welch, 37, starts his day by going to the gym, alternating between upper body and leg exercises, sometimes throwing in elliptical workouts.
Later in the evening, he typically runs for more than an hour and has a habit of sprinkling in calisthenic training throughout the day -- and even if the temperatures are below zero or sweltering, he'll be out there completing muscle-ups and chin-ups on the playground.
Although there are a number of knuckle pushup-related Guinness World Records already, there's never been an attempt at completing the most in 12 hours. So that's exactly the task Welch set for himself -- and on Aug. 11, he was able to do 6,050 in that time period, averaging 10 per minute.
When reached for comment by PEOPLE, a Guinness World Record spokesperson confirmed that they had received an application for the title and are "currently awaiting evidence to review."
What makes it an even more remarkable achievement is that just 17 years ago, Welch says he couldn't even lift a gallon of milk.
While squatting weight in high school gym class, Welch, 18, felt his right knee become uncomfortable. He stubbornly worked through the ache, but became concerned when it continued to worsen.
"That was a different level of pain," he tells PEOPLE. "Just felt like someone literally got a hammer and just beat your leg to death. It was hard to sleep just because it was always a throbbing pain deep inside the bone."
He wrestled with rheumatologists and endocrinologists for over a year to find out why he was stuck in a constant state of chronic pain. Despite having no answers, he enrolled in the University of Missouri-Kansas City (UMKC) pre-pharmacy program. After freshman year, he was forced to drop out when he could no longer walk around the campus.
"It felt like someone was just jabbing my knees and elbows with knives," he says. "It made my arm and hands go numb because it's just overwhelming."
Welch spent a year at home obsessively working to heal his body. He went to the library and checked out books about diet and exercise and set daily goals such as walking down the street to get better.
"I was trying to do sit-ups and crunches," he says with a laugh. "I'll never forget, I literally slid off the bed and I ended up tearing my stomach and I got a hernia. I'm like, 'What is going on? My body is falling apart.' "
Finally, in the winter of 2008, when he was 20, doctors at Mayo Clinic diagnosed him with osteoporosis, spondyloarthritis, an inflammatory disease that can worsen over time, and hypogonadism, which can impact muscle and bone mass. These diagnoses helped explain his years of debilitating pain -- and gave him a path forward.
"Up until then, I always thought I was mentally strong," he says. "It seemed like every week I was going to different doctors and specialists everywhere. It messed with my mind."
"It took a little while, but then my life started turning around," Welch says. "I almost became a new person. If you go through some crazy stuff, it just changes you."
Welch went back to school, earning his education degree from the University of Central Missouri, and after graduation he began teaching third grade at Gatz Brown Elementary in Moberly. He also started working out two to three times a day and took up obstacle course racing after a suggestion from his brother.
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When a shoulder injury forced him to switch from regular pushups to knuckle pushups, Welch began researching world records. Discovering that no one had yet claimed the 12-hour knuckle pushup record, he decided to go for it.
"I felt like I had a strong mindset and pain is one thing," he says. "When you train so much, you figure out strategies with your mind when you start suffering."
"I start thinking about why I'm doing this. This is to make God and my parents proud. They didn't give up on me," he explains. "I'm reliving past events. I'm going back to the time I was sitting in that house. I'm going back to the time where I'm suffering at school."
Partnering with Family Life Fellowship church, Welch livestreamed his 12-hour pushup marathon, taking quick breaks every 10 pushups to sip Gatorade or nibble on protein bars.
"I did that for several hours," he says with a chuckle. "I was able to keep that pace. But after a few thousand, my arms started going numb and like I was trying to shake them loose because they just didn't work."
By the end, his elbows were swollen and bruised, sticking out "like Popeye." But when he looked up to see a crowd gathered inside the church to cheer him on, it was all worth it.
"I was close to crying," he says. "I was like, golly dang, the whole community came out and they were cheering."