But she it wasn't always this way. After the birth of her third child the Ontario mom found herself battling an underactive thyroid condition which was playing havoc with her body and her health.
She says: “Throughout my 2nd and 3rd pregnancies, I couldn't keep weight on. My thyroid was over-active and totally out of whack. I only gained 10 pounds for both, unlike my first pregnancy, gaining 22lbs.”
Her doctor explained the seriousness of the situation and placed her on daily medication.
However Julie decided to take matters into her own hands and hit the gym, determined to pack on the mass through weight training.
She says: “I started going to the local YMCA joining in on classes and programs they offered, and at this same point I changed my eating habits. I began with a moderate program going to the gym 4 sometimes 5 days a week.
I started with the high energy step classes and kick boxing, moving up to a Rock Bottom class and 20-20-20 class. This is where I got introduced to free weights and I got hooked.
I loved seeing the changes my body was making, and it became almost like my addiction. I wanted and craved more change. I wanted to see my muscles work together and see the definition in my muscle groups.”
By 2008 she had entered her first contest and placed a hugely creditable 3rd in the London & Western Ontario NYTRO Fitness Classic Championships.
Friends told her she had packed on so much muscle that it was time to move up to the women's bodybuilding category – but this is one muscle mom for whom the initially controversial physique category was tailor-made.
She said: “I was told straight from the judges that I should try bodybuilding. I hold a lot of muscle - too much to continue competing in Figure.
“I would have to get bigger for bodybuilding or lose the muscle I worked so hard to get. Lose muscle? Not even an option in my mind.
“I chose to maintain what I had, because I did not want to go down the path of a bodybuilder. I liked the sparkles and glitter of the suits, being able to have hair, make-up, jewelry and heels on.
“To me, that was the physique that I strived for. I am a women, that holds more muscle and have the ability to train and diet down and not lose my sexy curves - total bonus for me.
“As I am sure you can imagine how absolutely excited I was, when Women's Physique was introduced. Ecstatic, is more like the word I would describe myself as. I feel like this is a category that was designed especially for me.”
It was a great call. In April 2012 she took first place GNC Stratford Championships and has gone, literally, from strength to strength.
And as can be seen from her new video her competitors better look out in 2013 too!
She said: “I am proud of everything I have achieved and worked for. I have curves, sex appeal, positive stage presentation, lots of muscle and I can dance.
“I am the total package. I continue to learn something new every day and I enjoy inspiring others to be their best! I am so very proud to represent women who aspire to be strong, powerful and sexy.”
Julie Lockhart is sponsored by FUSION BODYBUILDING.