Stretch is one of the most misunderstood activities in fitness. Because it is mostly assoicated with the "bend down and touch your toes" variety of exercise its importance is frequently overlooked and the benefits it can provide are lost.
As muscles grow and as they age, they change. A balanced stretching routine helps provide even more muscle growth along muscle fibers and increased flexibility, both of which provide a fuller range of motion, greater freedom to move our body as we wish and provide us with more power when we ask it to do somthing.
In addition to this strectching also helps achieve:
Increased flexibility in the joints.
Better circulation to the muscles and joints being stretched.
Increased energy levels (as better circulation brings in more oxygen and glycogen).
Better coordinated movements.
Increased speed and power.