Jennifer Aniston and Justin Theroux are obsessed with martial arts workouts.

Jennifer Aniston and Justin Theroux

Jennifer Aniston and Justin Theroux

The former 'Friends' star - who tied the knot with the 44-year-old actor in August - has enjoyed been enjoying yoga-style exercise Budokon for years and has now tempted Justin to join her for similar training to improve their upper body strength and cardio.

An insider said: "They've become great sparring partners.

"Jen's been into Budokon for years, and she and Courteney [Cox] used to do classes with well-respected martial arts teacher Cameron Shayne.

"Jen swears by it for upper body strength and cardio - and Justin's really into it now, too.

"It's fast becoming an obsession for them."

Justin is said to have been initially "reluctant" to join in with the martial arts alongside his 46-year-old wife because he was scared of harming her.

The source added to the National Enquirer: "Jen's been into martial arts for years. She's been urging Justin to try it with her for a long time, but he was reluctant because he hated the idea of hurting her.

"But since he tried these new routines he's become as hooked as Jen."