Seated vs Standing Calf Raise — The Muscle You Can't See

Standing calf raises train both calf muscles: the gastrocnemius on top and the soleus hidden underneath. Sit down and bend your knees - the gastrocnemius crosses the knee, so it goes slack, while the soleus (attached below the knee) keeps working. Straight knee trains both. Bent knee leaves the deep one. The violet highlight shows the deep soleus in the 3D model.