Age affects flexibility and mobility as the body's soft tissues naturally lose elasticity over time, leading to stiffer joints and decreased range of motion. This decline is often accelerated by a sedentary lifestyle and can result in increased risk of injuries and decreased physical performance. Regular physical activity, particularly stretching and strength training, can help counteract these effects by maintaining muscle and joint function. Incorporating flexibility exercises as part of the fitness routine is critical to promoting longevity in movement and enhancing the quality of life.