The calf being an immensly hard core shock absorber can be triggered by either a sudden explosive movement or a series of repetitive movements. If you experience it tighten up suddenly, this is typically your brains decision to pull it tight to protect itself from further harm.

Things that can help speed up recovery:

1. Stop doing the exercise or movement that may have caused it in the first place. Continuing on it is more likely to make the injury worse requiring a longer rehabilitation period.
2. Rest from weight baring activities. Evaluate, test and diagnose the injury to confirm what’s going on underneath.
3. Put in place a strength / conditioning and mobility program. Slowly return back to movement in a gentle, controlled, structured way to avoid repeating the same injury twice.

Irrespective of whether you have a quad, hamstring or calf injury, soft tissue injuries tend to come in 3 levels of grades:
Grade 1. Small level of soft tissue damage, possible to continue with sports providing it doesn't get worse. 
Grade 2. A medium muscle strain which you really need to consider whether it's wise to continue.
Grade 3. A full rupture, you'll know if it's a full rupture as you'd be likely to be carried off rather than walk.  

Grade sprains  / strains arent always as easy to determine as 1,2 or 3. Sometimes it can be a 1.4/5 or a 2.3 or 2.4. Never the less, anything in the 2's must be evaluated very seriously as you certainly don't want a low level 2 becoming a high level 2 simply for the sake of hitting your target training run. Needless to say, the higher the grade, the longer it'll take to repair and recover. Some of us learn this the hard way!

Let’s get on top of it properly and get you back moving with confidence.