Never perform a static stretch before going out for a run on cold muscle. One should always have a good 5-10 minute light jog then stretch. If you are doing more of a dynamic stretching then you can perform these on a colder muscle because the dynamic stretching is as much a warmup as a stretch. I cannot emphasis this enough especially for morning runners but even those who are evening runners. Frankly, I find that if my runners go out slow for the first 5 minutes then move the pace up you rarely need a pre-run stretch. But then most all my runners are post run stretchers.
The benefits of spending 10-15 minutes post run stretching are tremendous. You work to lengthen the fiber that want to contract post work releasing any pent up lactic acid in the fiber. I follow stretching with a session on a foam roller to work out any knotting in the muscle fiber. Once stretched, the icing is in order if you subscribe to that and a post workout recovery meal to feed the muscle.
I broke a rule by saying never
I know there are several runners who hop out the door and perform a deep set of static stretches just after hopping out of bed and never suffer an injury. These folks are the exception rather than the rule. More than likely they are genetically disposed to have a great set of loose muscle fibers and are less likely to suffer from fiber tears when cold.
A perfect plan would have you warm up for 10 minutes, stretch, run, warm down, stretch, roll and eat.
Shannon84
As far as the tight calves, this IS one of the most common issues with runners. I would run/walk for 10 minutes then stop and stretch the calves on a curb. Make sure that you are not pushing to the point of pain. Also you will want to hit all three calf muscles so start with heal neutral and stretch, then turn in slightly and stretch ad turn out slightly and stretch. Finally, make sure that you are hitting the calf muscles post run with a good stretch. Get a foam roller and roll the calf muscle again inner outer and mid to work out any knots in the muscle.