Thought of the week - Staying Sharp

My physical therapist tells me that sitting on the edge of my chair is healthy. It keeps my back straight and in a healthy pose. I like to sit at the edge of a chair to keep myself alert as well. Not to sink into a comfortable, lazy position which might influence my attitude for the day.

How do you stay awake for your day? How do you stay sharp and on the "edge of your seat"?