Stretch at the end of the exercise! Avoid muscle soreness and improve posture!
9 diagrams teach you to stretch correctly 
9 diagrams teach you to stretch correctly 9 diagrams teach you to stretch correctly 9 diagrams teach you to stretch correctly 9 diagrams teach you to stretch correctly 9 diagrams teach you to stretch correctly 9 diagrams teach you to stretch correctly 9 diagrams teach you to stretch correctly 9 diagrams teach you to stretch correctly Source: People's Daily
