In this paper theories, types and methods of stretching both in recreational as well as professional sport, flexibility development and modern stretching methods will be shown. In the first part key segments and function of the human body and the locomotor system are described. Flexibility, along with its forms and methods, is described. Factors upon which the level of flexibility depends on, like joint structure, body temperature, age, sex, etc., are also noted. Stretching physiology is described as well as the processes human body and locomotor system go through during stretching exercises. Types of stretching are listed and explained. Proprioceptive neuromuscular facilitation method is thoroughly explained because it represents most used method for flexibility training nowadays. Important points of how to stretch properly both in recreational purposes and in professional sport are also noted. Purpose of this work is to point out the importances of stretching in professional sport, as well as ones in recreational sport. In that regard, researches which discuss stretching in sport have been found. Those researches show that stretching can positively impact sports performance, quality and life and reduce the risk of injury. Modern stretching programs, pilates and yoga, are pointed out and explained. Also, their application both in recreational and professional sport is noted.