Cross Body Mountain Climbers
To do Cross Body Mountain Climbers, start in the high plank position with your hands under your shoulders and your feet about hip-width apart. Your body should be in a nice straight line from your head to your heels.
Then drive one knee in and across your body toward your opposite elbow. Feel your abs working to draw your knee in as the muscles around your rib cage work to help you twist to bring the knee across your body.
Place the foot back out and move into the plank position then tuck the other knee in and across your body.
Do not run as you would with regular mountain climbers but take a bit more time to really feel your core working as you pull the knee across.