Well, not as good as many believe, according to a study in the most recent issue of The Cochrane Database of Systemic Reviews.   The study brings to light the debate about whether stretching before exercise can reduce soreness.

The BBC reports that ?The available evidence suggests that stretching before or after exercise does not prevent muscle soreness in young healthy adults.?

Is this a reason to cut stretching out completely?  Absolutely not.  Even if other studies conclude that stretching does not prevent soreness, it does provide some "painkilling" effects after the onset of soreness.  Moreover, injury prevention is the primary reason for stretching, and while there are some naysayers, injuries resulting from cold, tight muscles are much more prevalent than those from warmed-up and stretched-out body parts.