Fitness trainer Autumn, most well known for creating the 21 Day Fix plan, has merged her love of both country music and building up a sweat to create Country Heat - a low-impact, high-energy workout.

While Autumn has long been a fan of the country sound, she wanted to make her new programme even more special by enlisting veteran singer Jo Dee to pen a song for the regime's soundtrack.

"Jo Dee and I had already been friends, we’d been in touch, we had already met at Beachbody headquarters about a year earlier, and that was the first thing I said was 'Oh my gosh, can we get Jo Dee to do an original song?'" Autumn smiled to Nashvillegab.com. "I went to her house and sat with her for a couple hours, talked about the feel I wanted the song to have, and the feel I wanted the line dance to have that was going to go with it. She was throwing ideas out there, and then over the next few months she would send me rough cuts of vocals, and 'Do you like this?' and that sort of thing."

The process resulted in Jo Dee penning Night Crawl, and Autumn choreographing a high octane line dance to go alongside it.

"As soon as she sent me the first rough cut of Night Crawl, I was like 'Yes! That’s gonna be fantastic!'" Autumn added. "And I think the line dance that I created to go with it is just so much fun."

While Night Crawl obviously has pride of place in the Country Heat workout, Autumn thought long and hard about which other country songs she wanted to include.

After much deliberation, she opted for tracks from Kenny Chesney, Jason Aldean and Tim MCGraw among many others.

"I’m a huge country fan, so I listen to it literally 24/7," she explained. "That’s usually what’s playing when I’m in the car, and I just picked my favourite songs and my favourite artists that make me want to dance. They’re the best of the best and their music is so fun and just makes you want to move and makes you happy."