I would just add to JMan to squeeze for about 2 sec pause and add a similar pause at the bottom of the rep (without the squeeze of course). This is supposed to remove the Achilles tendon from carrying the load. I use to do a tri set with 10 reps toes pointed out, ten pointed in, and finish with 10 straight. Pretty killer superset. I had to stop doing standing loaded because my back, but these worked pretty good and I recently had a competitive bodybuilder tell me I had nice calves, so I think it works.