Not necessarily. The results of several recent studies have shown that stretching before strenuous activity is not a surefire way to prevent injuries. Surprisingly, improving your general fitness has a bigger impact on preventing training-related injuries in the lower limbs.

This is not meant to discourage people from keeping good flexibility in their joints and muscles. You still need to warm up before heading out for your jog. This can be as simple as bouncing lightly on the balls of your feet. Also, "walk before you run" in order to gradually increase your heart rate. Once you've warmed up, you can start your jog.

Most health experts agree that stretching has more of an effect when muscles are warmed up. So you might want to consider stretching after your jog.