Cardio empty is correct. But eat something, say, half an hour to an hour before lifting. Some do carbs, some do protein, some do both.

Men often consume carbs AFTER, but in women, this may not be as helpful - many women (myself included) get fat when we try to get in post-workout carbs, althouth pre-workout carbs can work fine.

Currently, I do creatine with dextrose, and then a small whey shake just before lifting (fast digesting, both), followed by real (slow digesting) food after, no carbs after.

Couple of threads for you:
http://forum.lowcarber.org/showthread.php?t=187470
and
http://forum.lowcarber.org/showthread.php?t=194433