Whether cooking chicken, pork, steak, or any other type of meat, let it rest for half the time it took to grill. For example, a steak grilled for 18 minutes should rest for nine.
Once the meat is done cooking, it's still extremely hot, meaning its runny juices haven't quite set. When you cut into it, they'll spew everywhere, leaving dry, tough meat.
However, if you let the meat rest for about as half as long as it took to cook, the muscle fibers inside relax, distributing the juices and producing a tender piece of meat.