John Cena is releasing a series of children's books.

The 40-year-old professional wrestler has revealed he plans to make his debut as an author with the release of a new line of children's stories published by Random House Books for Young Readers.

The series will follow the lives of a boisterous family of monster trucks named Elbow Grease, Pinball, Flash, Crash, and Tank, and the first book - entitled 'Elbow Grease' - will centre around the first of the trucks, who is smaller than his four brothers but on a mission to prove that he has the guts, grit, and gumption to do big things.

In a press release, John said of the series: ''With 'Elbow Grease' and the books to follow, I want to offer kids a fun and engaging way to learn about the power of ambition, dedication, and heart. These concepts have been transformative in my life, from my childhood up to now, and it's so important to me to pass the positivity on and help our youngest generation see that right mindset is key to achievement.''

The book is being illustrated by Howard McWilliam, and is due for release on October 9 this year.

Despite launching the book series for children, John - who is engaged to fellow wrestler Nikki Bella - previously admitted he doesn't think he'd make a good father.

Asked if his stance on having a baby has changed, he said: ''Right now it hasn't changed. I can barely raise myself, so I just don't know how good a dad I'll be. I guess that's my biggest fear.''

However, the sport star has nothing but good things to say about his 33-year-old fiancée - who is the twin sister of Brie Bella - though, as he said he's ''very fortunate'' to have her by his side.

He added: ''I was very fortunate to find a partner that I want to share my life with who is as driven as I am. We are literally working our tails off.''