Dave, standing burns no more calories than sitting. Learned that 50 years ago in my Anatomy and Physiology classes. You just get tired faster, IMO, and though you may sing better because you can move your diaphragm slightly more, you can achieve the same thing while sitting atop a stool like DonM and I did for years. Some folks think it makes them look more professional, but I disagree wholeheartedly with this assessment. When makes you look professional, on a stage, or at floor level is your overall appearance and your ability to connect with your audiences - nothing more nothing less.

Just my .02 cents worth,

Gary