Holding a plank is a challenge, but holding a plank with your knees bent is equally challenging! Keep your knees tucked under your hips and your core engaged. I sometimes like to incorporate this as a hold on on leg after a tabletop set of glute work with the working leg up in the air (such as my go to set), but it’s a great core exercise as well.
After holding the position for a while, you can alternate stepping one leg at a time back into a full plank position, then take up the tempo to a run for a transition into a full plank.
