What are the best core-strengthening exercises for beginners? for better balance, strength, and preventing injuries.

Yoga: Yoga is great for core strength and balance.

See below: There are many great core strengthening exercises. I would recommend a visit with a physical therapist or personal trainer to learn proper technique. One of the best exercises are called planks. To do this lay on your stomach and lift your belly and legs off the ground with your forarms and toes on the ground. Try holding this postion for 15-30 seconds at a time.