Khloé Kardashian Spills the BOSU Ball Workout She Uses to Get Defined Abs

Khloé Kardashian just dropped her current ab workout routine, and it's not for the faint of heart. In a May 4 Instagram post, Kardashian goes into detail about the exercises she does to build strength. Warming up in hot-pink Fabletics leggings and a matching Nike sports bra, she tells the camera, "Bracing myself because Don gets a little crazy," referring to celebrity trainer Don Brooks, the creator of the "Donamatrix" training method. She then pans to Brooks, who rubs his hands together and says, "Let the games begin."

Kardashian begins with lateral kicks using resistance bands and a BOSU ball, which she's included in many of her workout sessions. According to her, this equipment activates her glutes and core before she jumps into more intense movements. From here, she breaks her routine down into four quarters, with three sets and 20 reps of each exercise, along with an additional "overtime" segment.

The first quarter consists of a BOSU ball power-knee exercise, with Kardashian lifting one knee up and back down directly behind her with the other planted in the middle of the ball. The next quarter is more ab-focused, with lower-abdominal leg scissors. Kardashian reminds her followers to "keep your stomach drawn in tightly, rib cage down, and remember to breathe" for optimal results.

Third, Brooks demonstrates a curtsy lunge, pushing through his front leg to step up onto the BOSU ball. Kardashian explains that this will "get your heart rate up while working your lower body and core," following Brooks's lead. In the fourth quarter, she runs in place on the ball, saying, "My heart rate was in my brain with this one." BOSU ball knee tucks with resistance bands serve as the final "overtime" exercise, strengthening the obliques.

"That was crazy, but the best kind of crazy," Kardashian says at the end of the video. "That was an intense workout, and I'm exhausted, but I'll get a second wind." She adds that she always feels "so accomplished" afterward, usually drinking a protein smoothie and taking a much-needed breather. "I hope everyone has a great day and does something active — doesn't matter how big or small. Any step is the right step."

Directions: For each quarter below, you'll do 20 reps of the exercise on each leg (using the BOSU ball, if you have one). Repeat this combination three times, then move onto the next quarter. When you're done, make sure to cool down or stretch.