triceps surae

So why is that? Well, we don't know, but I have a theory.

And part of the reason is to do with the makeup of the calf muscle itself.

You see your Achilles tendon is that big tendon that inserts into your heel bone on the back of your foot.

And it comes from two muscles, your soleus and your gastrocnemius.

Your gastrocnemius is the big muscle, the calf muscle that you can see.

And the soleus sits underneath that closer to the bone.

The two come together to form the Achilles tendon before it inserts into the heel.

Slower, endurance, walking, standing, running slowly, that's your soleus.