On Thursday, the 42-year-old busted out a difficult workout on her Instagram stories, showing off her toned physique and skill in the gym.
Mulroney's trainer, Danielle Milner, a strength and conditioning specialist at Catalyst Health in Toronto, originally posted the videos which saw the Canadian star effortlessly performing a TRX routine.
TRX, which stands for Total Body Resistance Exercise, is "a revolutionary workout method that uses your body weight and gravity as resistance to build strength, balance, coordination, flexibility, core and joint stability."
To break a sweat, the stylist and marketing consultant rocked a very Canadian ensemble — a red ball cap, red sports bra and white leggings. In the clips, Mulroney grabbed the TRX equipment, pulling herself up and down to give her arms and core a killer workout.
On the stories, Milner wrote: "Try this TRX circuit: repeat 3x! 20 reverse flyes, 20 TRX triceps, 20 inverted rows, 20 side spider abs, 20 plank to pikes," referring to the exercises she gave Mulroney in case fans wanted to try it at home.
This isn't the first time the mother-of-three showed off her strength on social media. Last week, Mulroney posted an Instagram video of a gruelling core workout curated by Milner.
The stylist flaunted her svelte figure in lavender workout gear and wore her long brunette hair in a sleek braid.
Fans adored Mulroney's workout style and begged to know her fitness secrets.
"You make it look so gracefully easy, but it's not. Love your workout outfit!" commented a follower.
"Love the purple getup! Looking styling! But how did you get so strong? Spill the details!" wrote another.
"Inspiring. You also inspired me to try Pilates and I’ve now been doing it for nearly three years. I love it and what it has done for and to my body! So thanks!" a fan told Mulroney.
"A girl could only dream of a core like yours, how do you do it?" said someone else. "That colour also looks great on you."