"Doing push-ups on an exercise ball totally changed my arms," the 33-year-old wrote on her blog.
Khloe is now seven months pregnant so is currently giving the move a miss, but she warns anyone who’s keen to try that "your arms will feel like Jell-O when you're done”.
To give a try yourself, set yourself up near a wall and press your heels against it for stability. Plank on the exercise ball with your hands shoulder-width distance apart. Keep your body in a tight, straight line and press down with you elbows bending beside your body. Use your momentum to bounce back into a plank position and repeat the process.
Khloe says that she does 30 to 50 whopping reps at a time.
But the move isn’t for everyone – if you have wrist, elbow or shoulder issues (or, like Khloe, you've got a baby on board) it might be best to stick to an ol’ fashion push up. You can make it harder by doing it on a bosu ball instead.
The mum-to-be has previously snippets of her hardcore workouts, including the arm heavy session below.
Who else is inspired to hit the gym ASAP?!