You've been doing: Machine calf raises
Switch to: Barbell standing calf raises
A calf-raise machine may allow you to pile on the weight, but that's only because it's doing part of the work for you. And while that makes your lifting easier, it also prevents your calves from doing their main job, which is balancing your body as you move. The end result? You lose a major stimulus for muscle growth. Ever run in the sand till your calves burned? That's the kind of workout you'll get with the barbell standing calf raise, which forces your calves to stabilize you with a heavy load on your shoulders - ensuring the hard work you do is all your own.
HERE'S WHAT YOU DO
Set up a barbell in a squat rack as if you were going to do squats. Take the bar off the rack, set your feet about shoulder-width apart, and bend your knees slightly . Drive the balls of your feet into the floor while powerfully raising your heels, as in a normal calf raise . Hold the position for five seconds, and then slowly lower your heels to the floor. That's one rep. Perform three to four sets of 10-12 reps, resting one minute between sets.