Having strong calf muscles are what gives our lower legs that often sought after well-defined look, but having strong calf muscles also aids running and walking by allowing for ankle extension. While many of us find working the quadriceps (front thigh) and hamstrings (back thigh) a natural part of our workout routine, do not underestimate the power of working this group of muscles.
Two of the major muscles that make up the calves include the gastronemius (the outer calf) and the soleus (the inner calf). By doing a variety of calf strength training exercises and stretches you are ensuring that you are targeting all muscles involved.