At his heaviest, Hearn was almost 19st (266lbs) and so weighed more than several of the top heavyweight boxers in his stable.

The 44-year-old notes that Matchroom’s ambitious broadcast deal with fledgling streaming service DAZN in 2021 made him significantly busier in his work life, giving him little time to focus on his fitness.

“The workload trebled,” Hearn told Men’s Health UK, “And I just thought to myself, one, ‘You can’t do this for very long if you continue living the same lifestyle,’ and two, ‘You might die.’

“As extreme as that sounds, I’ve got a history of heart problems in the family.

6Hearn has noticeably lost weight from his past picturesCredit: Mark Robinson/Matchroom6His transformation is impressiveCredit: David Venni / Men’s Health UK

“I’ve got a job that’s full of stress. I’m not really sleeping. My diet’s s***. I’m not training that much. I’m overweight. It’s all the classic signs of a short lifespan.”

Hearn began to turn things around by running regularly and cutting back on his alcohol intake.

This strategy saw him lose 2st (28lbs), but only made him more ambitious to keep progressing.

He therefore embarked on a ten-week campaign to build muscle mass aided by his long-time trainer Kai Peacock, Men’s Health coach Tom Kemp and Men’s Health editor Andrew Tracey.

6A small team of coaches helped HearnCredit: David Venni / Men’s Health UK6He says he is now in the best shape of his lifeCredit: David Venni / Men’s Health UK

“I always said that the reason my arms are so small and I don’t have any muscle mass is down to my genetics,” Hearn said.

“I always used that as an excuse because my dad’s not really a big guy either. But it’s actually a load of rubbish.”

Indeed, Hearn’s arm and shoulder muscle has grown drastically as a result of his work in the ten weeks.

His dumbbell bench press doubled from 20kg to 40kg and he also managed to take two minutes off of his best 5k time, which is now just over 22 minutes.

6Hearn is adamant he will remain committed in 2024 and beyondCredit: David Venni / Men’s Health UK

Hearn concluded: “When I wake up in the morning, I go into the bathroom and I get a glimpse of myself and go, ‘F***ing hell yeah.’

“That’s good enough. That makes me feel great for the day.

“Right now, physically, I feel better than I’ve ever felt in my life, and I’m 44 years old.

“I’m excited to see what’s going to happen in six months, what’s going to happen in 12 months, what’s going to happen in three years.”