Joe Wicks, the fitness coach and nutritional guru, will take listeners back to his challenging childhood in a candid conversation with the host of Desert Island Discs, Lauren Laverne, on the BBC Radio 4 show on Sunday.

Filled with emotion and close to tears, the 33-year-old from Epsom, Surrey, whose online PE classes have now reached an international audience of millions, confides that in a moment of sorrow and frustration he once said he hated his father, Gary, a recovering drug addict.

“I was just so angry at the time because he had relapsed again,” Wicks admits. “I only said it once, and I have never really admitted that [I said that]. It was just a reaction and I felt so bad afterwards. I didn’t hate my dad. What a horrible thing to say.”

Wicks said he has since managed to move on, finding sympathy for his father and recognising the difficult childhood he has survived.

“I have had that anger, and that has completely passed. The antidote to addiction is connection and love. It has allowed me to find peace,” he says. “He is clean today. Narcotics Anonymous has worked for my dad, although he has had times when he has relapsed. I have more empathy now. He needs me to tell him I love him. I am learning to pull him closer. Unconditional love is so important for people with addiction.”

Wicks is now able to take pride in the life stories of both his parents. Choosing music from Bob Marley that reminds him of his father, and a track by Van Morrison that reminds him of life at home with his mother, Raquela Mosquera, Wicks says he would take a guitar with him during his time as a castaway so that he could learn to play his favourite songs.

The council home he lived in with his siblings was on a noisy estate, and Wicks explains that he always imagines someone in a similarly confined space when he puts together his daily 9am fitness shows for YouTube.