causes of sudden calf pain whilst running?

[Skandia]

Only on run 3 week 2 but just at the end of the 4th 90 secs I got sudden onset of severe calf pain in R leg. It felt like cramp but didn't go away. Had to limp home. Still in pain now an hour later.

Any tips to avoid it happening again? And how to recover now?

[Grammadog1947 Graduate]

This addresses night-time calf cramps...but it is good advice, and may be helpful...Stretching and hydration (water) are keys, especially in this heat... dummies.com/how-to/content/...