The TRX Alt Knee Drive plank is a challenging core exercise that also engages the shoulders, chest, and arms. Begin by adjusting the TRX straps to mid-length and securing the handles at approximately knee height. Assume a plank position facing away from the anchor point with your feet in the foot cradles of the TRX straps. Engage your core muscles and maintain a straight line from head to heels. Then, drive one knee towards your chest while keeping the other leg extended, using your core to pull the knee in as close to your chest as possible. Return the leg to the starting position and repeat on the other side. Alternate legs for the desired number of repetitions while focusing on maintaining stability and control throughout the exercise.