Do you often wake up from LD with elevated pulse?

...if you were running/flying? Often wake up in sweat?

If this is the case, you are getting overly excited/emotional in your lucid dreams. This isn't detrimental to your health or anything, but it will cause you to wake up prematurely. You can have fun and be emotional, but try to keep them in check. Just practice learning that balance of emotion, so you are able to stay in the dream state longer. Don't worry, this is normal stuff.