5-Minute Core-Strengthening Workout For Runners

• Lying on your back, extend your arms out to your side as an anchor. Bring your knees up to a 90-degree angle.
• Starting the movement from your core, rotate your knees to the left, stopping just before they touch the floor. Slowly bring legs back to center, then lower the legs rotating to the right.
• Continue alternating side for one minute.

Tip: If your back feels strained from this, place your feet on the floor with bent knees and rotate your knees back and forth, keeping your feet on the ground.