The reality TV star was spotted heading to her car on Tuesday (27 August) after a workout session and sporting an eye-catching slogan top, which was emblazoned with the word 'twerk', and a pair of grey jogging bottoms.
She also wore a pair of black biker boots and carried a small black handbag, while tying her long dark locks up into a messy bun and ditching her make-up in favour of a natural and fresh face.
Kylie is clearly committed to her gym routine, as she and the rest of her large family - including sisters Kendall, Khloe, Kourtney and Kim - are regularly seen leaving an intense workout in Los Angeles, ensuring that their enviable bodies are kept in shape.
Given that Kylie - who celebrated her 16th birthday this month with an Alice In Wonderland themed bash - is also a part-time model and has even starred in a music video recently for new group The Boy Band Project, it's no wonder that she is keen to stay fit.
And since she is wearing that T-shirt, perhaps she is also incorporating some twerking into her workout too?!
Although the dance craze known as twerking has been around for a number of years, it has become particularly popular lately after pop star Miley proved to have a special talent for it in a YouTube video uploaded earlier this year.
The former Hannah Montana actress then took her moves to the main stage on Sunday (25 August) at the MTV Video Music Awards, where she performed a rather controversial routine alongside R&B singer Robin Thicke.
We wonder if that performance could be another one of the reasons behind Kylie's fun exercise outfit?
Also caught leaving the gym yesterday was older sister Khloe, who kept a low profile following reports of relationship troubles, and Kylie's father Bruce Jenner.
What do you think of Kylie's T-shirt? Let us know below, as the best comment each week wins £50!