Two muscles, two knee positions. Training calves only standing leaves one of them out.
PrimarySecondaryNot worked
Gastrocnemius, the visible diamond, crosses both knee and ankle: it only works fully with the leg straight. Soleus, underneath, crosses only the ankle — it dominates as soon as the knee bends. Hence two families of movement: standing for one, seated for the other.
Twelve to twenty sets a week, half straight-legged and half bent-knee. Full range matters most: drop well below horizontal and hold a second at the top. Calves take high frequency, three or four times a week without trouble.
Bouncing off the Achilles between reps. Control the descent and hold the bottom — the bounce trains tendon elasticity, not muscle.
Names are the ones the app uses.