Core exercises are an important part of strength training that builds muscles in your pelvis, abdomen, and spine. Building a strong core helps you to maintain good posture, boosts your mobility and endurance, alleviates lower back pain, and helps you avoid falls and injury as you get older. Some examples of core exercises include reverse crunches, planks, bridges, and prone arm and leg raises. Activities such as yoga, Pilates, swimming, beach volleyball, kayaking, and surfing also provide a good core workout.