Try this when you do them. You will probably hurt for a couple days. No matter which exercise you do, do the reps slow. At the top, hold for a 2 count, lower slowly. Then hold the stretch for 15 seconds. yes. You should feel the stretch, then squeeze hard at the top. Pick a weight that you fail at rep 6-7, and push through to 10-12. Do a standing or straight leg calf press, and a sitting one. Do three sets of each. If you work them hard enough and properly, you shouldn't be able to do them twice a week, because you won't want to hurt for 7 days.