Shoulder pads and standing tall for max calf size.
Keep your legs straight and chase a full stretch to a full extension every rep.
With the load on shoulder pads and your knees locked straight, this machine puts the gastrocnemius under stretch and load through the biggest range you can give it, heels sinking below the platform and driving to a full toe point. The fixed path means you can go heavy without balancing anything, and heavy loaded stretch is exactly what stubborn calves respond to. It is the standard mass builder for calves for a reason.
Both, for different parts. Standing with straight legs hits the gastrocnemius, the muscle you actually see, seated with bent knees hits the deeper soleus. If you only pick one for size, pick standing.
Slower than you think, especially the lowering. Two to three seconds down into a full heel-drop stretch, brief pause, then drive up. Fast bouncy half reps are why most people's calves never change.
It usually just means you are reaching a peak contraction they are not used to. Ease off the hold slightly, stay hydrated, and it tends to settle as the muscle adapts.
