Your adductors (inner thighs) also play a primary role in stabilizing your knee and hip joints during running. This multi-joint exercise targets your adductors, hip flexors, and abs.
How to do it: Lie faceup with the ball between your bent knees, feet flexed. Place your hands behind your head and focus on squeezing your ankles and knees into the ball. Brace your abs in tight and crunch up, lifting your head and shoulders off the floor as you bring the ball in towards your chest. Slowly lower back down to your start position.