The type of exercise most beneficial for building bone density includes resistance training and weight-bearing activities. Exercises like weightlifting, running, and bodyweight exercises, such as squats and lunges, create stress on the bones, prompting them to strengthen in response. High-impact activities where the body works against gravity effectively stimulate bone formation, reducing the risk of osteoporosis and fractures. Additionally, incorporating balance and flexibility training can help prevent falls, further protecting bone health. Therefore, a well-rounded program combining these elements is essential for maintaining strong, healthy bones over time.