Calves push your toes down. This is very important for sprinting, jumping, reversing direction, and stability. Strengthen you calves to increase your acceleration and jumping. Sever your achilles tendon, and all you can do is walk slowly. I tore my achilles several years ago. Here is a list of calf strengthening exercises that I made, progressing from easiest to hardest. Reps should be in the 20-50 range since the calf muscles have very high endurance (except plyos, where quality is more important than quantity). 3-10 sets per session (1-3 exercises). Recovery time is pretty quick and can be less then 24 hours between training sessions for low intensity exercises. Plyos and heavy weight training should be several days of recovery and no more than twice a week. If you are sore the next day, do something light and easy to help recovery and then do something high intensity the next day.
Band pushes - loop a towel, long rubber strap, or bicycle tube around your toes and push while pulling with your arms.
Knee lifts - while sitting, push toes against floor and lift knees, hold at top.
Standing heel raises from floor
Heel raises from a step. Stretch at bottom.
1-leg standing heel raises from floor
1-leg heel raises from a step.
1-leg heel raises while holding a dumbbell in one hand.
Hop in place
Juggle a soccer ball with only one leg.
(It took me about 2 years after surgery to do the following safely)
Hop forward, backwards, sideways.
Hop over a soccer ball, back and forth or side to side
Sprint up a hill
Raquetball, tennis, basketball (hard court sports with change of direction)
If you just want big calves, then do 5 sets of 25 reps of seated calf raises, then do 5 sets of standing calf raises, then do 5 more sets of donkey calf raises or one leg weighted heel raises. Wait two or three days, then repeat with more weight. Once a week, do 6 reps of seated calf raises (A) as heavy and explosively as you can, then run over to the standing calf raises (B) and do 12 reps, smooth and controlled, then back for 6 more of A, then do 40 super slow reps of heel raises (C) on a board or step with a good deep stretch, then back to A to B to A to C to A to B to A to C. No rest just A-B-A-C-A-B-A-C-A-B-A-C. You must do B and C slowly, or you will not be able to do A. The theory is the fast twitch fibers are recovering while the slow twitch ones are working. Reality - 10 minutes of pure hell and several days of walking funny.