Runners following a training program tend to focus on building endurance and speed. Yet, a flexible body is more efficient, sees more gains in strength and endurance, enjoys more range of motion, is less injury-prone, recovers more quickly, and simply feels better. Regular stretching is a must.
Before stretching, always jog at least 10 minutes to warm up the muscles. Never stretch "cold" muscles. Also, you should always take time to stretch after a run.
Studies suggest using just one form of stretching is not as beneficial as using a variety of stretching routines. Using a variety of stretching exercises will allow athletes and runners to experience the full effects of stretching.