The calf muscle is made up of 2 muscles:

1. Gastrocnemius

2. Soleus

The gastrocnemius is the larger calf muscle compared to the soleus. The soleus is the smaller flat muscle which lies underneath the gastrocnemius.

The gastrocnemius is important in powerful explosive movements as it is mostly made up of type 2 fibers. The soleus is mostly made up of type 1 fibers where it is important in endurance.