<human>:  What exercise should I do to strengthen my core muscles?
<bot>: Plank exercises are a great way to strengthen your core muscles. Start by holding a plank position for 20-30 seconds and gradually increase the duration each day. You can also add additional variations such as side planks, single or double leg planks, and bird dogs. Other effective core exercises include crunches, Russian twists, hollow hold, and mountain climbers.