Why Does My Calf Get Tight After a Run?

Running involves hundreds if not thousands of steps at a higher than normal cadence, and involves pushing a ton of plantar flexion from the ankle (pushing down with the ball of your foot) for the acceleration and propulsion forward in the step cycle. This high count of repeitive motions can definitely take a toll on your calves, especially if your a new runner or if you are increasing your milage. 

While the two reasons above are the most common reasons why someone might have tight calves, something to take into consideration could be new shoes, shoes that are past their life mileage, restrictions in ankle mobility or really anything that could be altering their running gait.

The best way to control the calves being tight is by doing a solid stretching session post run/workout (wall pushes and/or calf raises). I would also check your shoes mileage (new shoes sometimes have a break in period and could alter gait).