You cannot isolate the outer edge of the calves completely, but there are ways to position your feet and ankles so that you can emphasize the outer part while performing calf exercises. It is important to strength train the inner edges too for balance and symmetry so that your calves look good and functional optimally.
Outer Calf Foam Rolling
Before a workout, it is ideal to use a foam roller. Foam rolling decreases muscle density and gives you a massage to better prepare your muscles for a warm-up. Foam roll the outer calves by lying sideways on the floor with a foam roller under your outer knee, perpendicular to the leg. Prop up your upper body with both forearms on the floor so that your shoulders are twisted slightly to the left, and then pull yourself forward with your arms so that the roller moves down your outer calf. Then, do a short five- to 10-minute aerobic warm-up such as marching in place or walking on a treadmill.
Weighted Plates Standing Calf Raises
After warming up, you can begin resistance training exercises for the outer calves. Using weighted plates to stand on with only one side of the foot causes you to emphasize the outer calves as you do the exercise because of the position of the ankle. This exercise also increases ankle stability. To begin, place two large plates on the floor 6 inches apart. Stand with the outer edge of your feet on the plates and the inner edge of your feet on the floor, then rise onto the balls of your feet. Perform eight to 12 repetitions.
Seated Calf Raises
You can also use weighted plates to emphasize the outer edge of the calves when performing seated calf raises. Seated calf raises emphasize the calves in a different manner and thus exercisers often perform standing and seated calf raises together in a calf workout. To perform seated calf raises for the outer calves, sit with your feet on two plates as positioned in the standing calf raises exercise and your knees bent so the thighs are parallel to the floor. Hold the bar of a barbell on your lap just above each knee with your palms facing inward, and then rise onto the balls of your feet. Perform eight to 12 repetitions.
High Incline Calf Walking
High incline calf walking is an effective exercise for developing mass in both the inner and outer edges of the calves. Set the treadmill to the highest incline and walk slowly. Exaggerate the motion each time you push off the ball of your foot to take a step. Walk for five to 10 minutes on the treadmill. Do a total of three sets and rest for three minutes between sets.