The type of exercise most beneficial for improving flexibility is typically stretching. This practice can be categorized into static, dynamic, and proprioceptive neuromuscular facilitation (PNF) stretching. Stretching exercises enhance the elasticity of muscles and connective tissues, improving overall range of motion and reducing the risk of injuries. Regularly including these exercises in a fitness routine can help maintain joint health and support athletic performance, making flexibility training an essential aspect of comprehensive physical fitness.