Wow! Really appreciate the input from everyone! I'm just gonna run this by you guys just to make sure I have it right.
Va is defined as the highest speed that an a/c can be at where abrupt control movements will just cause it to stall, not break. In our C172's, Va is 90 (for the basic empty weight) to 105 (at max gross weight), and if we use abrupt control movements at or higher than whatever speed pertains to our weight, we risk structural damage.
Does it sound like I have it right?