Why flexibility is important? Without agility, flexibility and normal range of motion in the joints, the body is more prone to injury. Low flexibility reduces the body’s capacity for work and increases the risk for injury and illness. Reduced flexibility and range of motion is usually first experienced as fatigue and later on by injury or disease. To ensure full body stability and balance, the range of motion and flexibility in each joint should be normal. This is best accomplished using a structured and well balanced strength training program performed on biomechanically well designed strength training machines (such as X-Force).